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Kamtam DN, Binkley MS, Kapula N, Sadeghi C, Nesbit S, Md HHG, Chang J, Maxim PG, Diehn M, Loo BW, Shrager JB. First in human Phase I Clinical Trial of Stereotactic Irradiation to Achieve Lung Volume Reduction (SILVR) in Severe Emphysema. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00479-6. [PMID: 38615887 DOI: 10.1016/j.ijrobp.2024.03.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/14/2024] [Accepted: 03/30/2024] [Indexed: 04/16/2024]
Abstract
PURPOSE Only a subset of patients with severe emphysema qualify for lung volume reduction surgery or endobronchial valves. We previously demonstrated that Stereotactic Ablative Radiotherapy (SABR) of lung tumors reduces lung volume in treated lobes by creating localized lung fibrosis. We aimed to determine the safety and, secondarily, explore the efficacy of Stereotactic Irradiation for Lung Volume Reduction (SILVR) over 18 months following intervention in patients with severe emphysema. METHODS AND MATERIALS We conducted a single-arm prospective clinical trial in eligible patients with severe emphysema treated with unilateral SABR (45 Gy in three fractions) to a target within the most emphysematous region. Primary outcome was safety i.e., incidence of grade≥3 adverse events. Secondary outcomes of efficacy were also explored. RESULTS Eight subjects received the intervention. Median (range) baseline characteristics were age 73 years (63-78), FEV1% 28.5% (19.0-42.0), DLCO% 40% (24.0-67.0), and BODE index 5.5 (5-9). The incidence of grade≥3 adverse events was 3/8 (37.5%). The relative Δtarget lobe volume was -23.1% (-1.6,-41.5) and -26.5% (-20.6,-40.8) at six and 18 months, respectively. Absolute ΔFEV1% was greater in subjects with BODE index ≤5 vs. ≥6 (+12.0% vs. -2.0%). The mean baseline lung density (in Hounsfield units, reflecting the amount of preserved parenchyma) within the intermediate dose volume (V60BED3) correlated with the absolute Δtarget lobe volume at 18 months. CONCLUSIONS Stereotactic Irradiation for Lung Volume Reduction appears to be safe, with a signal for efficacy as a novel therapeutic alternative for patients with severe emphysema. SILVR may be most safe/effective in patients with lower BODE index and/or less parenchymal destruction.
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Affiliation(s)
- Devanish N Kamtam
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Michael S Binkley
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA
| | - Ntemena Kapula
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Cheyenne Sadeghi
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Shannon Nesbit
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Haiwei Henry Guo Md
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Joon Chang
- Division of Pulmonary Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine School of Medicine, Irvine, California, USA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA; VA Palo Alto Health Care System, Palo Alto, California, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA.
| | - Joseph B Shrager
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA; VA Palo Alto Health Care System, Palo Alto, California, USA.
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Ashraf MR, Melemenidis S, Liu K, Grilj V, Jansen J, Velasquez B, Connell L, Schulz JB, Bailat C, Libed A, Manjappa R, Dutt S, Soto L, Lau B, Garza A, Larsen W, Skinner L, Yu AS, Surucu M, Graves EE, Maxim PG, Kry SF, Vozenin MC, Schüler E, Loo BW. Multi-Institutional Audit of FLASH and Conventional Dosimetry With a 3D Printed Anatomically Realistic Mouse Phantom. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00433-4. [PMID: 38493902 DOI: 10.1016/j.ijrobp.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/03/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
PURPOSE We conducted a multi-institutional dosimetric audit between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3-dimensional (3D) printed mouse phantom. METHODS AND MATERIALS A computed tomography (CT) scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene (∼1.02 g/cm3) and polylactic acid (∼1.24 g/cm3) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid (∼0.64 g/cm3). Hounsfield units (HU), densities, and print-to-print stability of the phantoms were assessed. Three institutions were each provided a phantom and each institution performed 2 replicates of irradiations at selected anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. RESULTS Compared with the reference CT scan, CT scans of the phantom demonstrated mass density differences of 0.10 g/cm3 for bone, 0.12 g/cm3 for lung, and 0.03 g/cm3 for soft tissue regions. Differences in HU between phantoms were <10 HU for soft tissue and bone, with lung showing the most variation (54 HU), but with minimal effect on dose distribution (<0.5%). Mean differences between FLASH and CONV decreased from the first to the second replicate (4.3%-1.2%), and differences from the prescribed dose decreased for both CONV (3.6%-2.5%) and FLASH (6.4%-2.7%). Total dose accuracy suggests consistent pulse dose and pulse number, although these were not specifically assessed. Positioning variability was observed, likely due to the absence of robust positioning aids or image guidance. CONCLUSIONS This study marks the first dosimetric audit for FLASH using a nonhomogeneous phantom, challenging conventional calibration practices reliant on homogeneous phantoms. The comparison protocol offers a framework for credentialing multi-institutional studies in FLASH preclinical research to enhance reproducibility of biologic findings.
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Affiliation(s)
- M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Kevin Liu
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jeannette Jansen
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland
| | - Brett Velasquez
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Luke Connell
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Joseph B Schulz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Aaron Libed
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Aaron Garza
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - William Larsen
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California
| | - Stephen F Kry
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston, USA
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland; Radiotherapy and Radiobiology Sector, Radiation Therapy Service, University Hospital of Geneva, Geneva, Switzerland.
| | - Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California.
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Ko RB, Abelson JA, Fleischmann D, Louie JD, Hwang GL, Sze DY, Schüler E, Kielar KN, Maxim PG, Le QT, Hara WH, Diehn M, Kothary N, Loo BW. Pulmonary interstitial lymphography: A prospective trial with potential impact on stereotactic ablative radiotherapy planning for early-stage lung cancer. Radiother Oncol 2024; 191:110079. [PMID: 38163486 DOI: 10.1016/j.radonc.2023.110079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 12/29/2023] [Indexed: 01/03/2024]
Abstract
This prospective feasibility trial investigated pulmonary interstitial lymphography to identify thoracic primary nodal drainage (PND). A post-hoc analysis of nodal recurrences was compared with PND for patients with early-stage lung cancer; larger studies are needed to establish correlation. Exploratory PND-inclusive stereotactic ablative radiotherapy plans were assessed for dosimetric feasibility.
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Affiliation(s)
- Ryan B Ko
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Oakland University William Beaumont School of Medicine, Auburn Hills, MI, USA.
| | - Jonathan A Abelson
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Coastal Radiation Oncology, San Luis Obispo, CA, USA.
| | - Dominik Fleischmann
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - John D Louie
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Gloria L Hwang
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel Y Sze
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Emil Schüler
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Department of Radiation Physics, Division of Radiation Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Kayla N Kielar
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Varian Medical Systems, Stanford, CA, USA
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Department of Radiation Oncology, University of California, Irvine, CA, USA
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Wendy H Hara
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Nishita Kothary
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA.
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Gensheimer MF, Gee H, Shirato H, Taguchi H, Snyder JM, Chin AL, Vitzthum LK, Maxim PG, Wakelee HA, Neal J, Das M, Chang DT, Kidd E, Hancock SL, Shultz DB, Horst KC, Le QT, Wong S, Brown E, Nguyen N, Liang R, Loo BW, Diehn M. Individualized Stereotactic Ablative Radiotherapy for Lung Tumors: The iSABR Phase 2 Nonrandomized Controlled Trial. JAMA Oncol 2023; 9:1525-1534. [PMID: 37707820 PMCID: PMC10502697 DOI: 10.1001/jamaoncol.2023.3495] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/11/2023] [Indexed: 09/15/2023]
Abstract
Importance Stereotactic ablative radiotherapy (SABR) is used for treating lung tumors but can cause toxic effects, including life-threatening damage to central structures. Retrospective data suggested that small tumors up to 10 cm3 in volume can be well controlled with a biologically effective dose less than 100 Gy. Objective To assess whether individualizing lung SABR dose and fractionation by tumor size, location, and histological characteristics may be associated with local tumor control. Design, Setting, and Participants This nonrandomized controlled trial (the iSABR trial, so named for individualized SABR) was a phase 2 multicenter trial enrolling participants from November 15, 2011, to December 5, 2018, at academic medical centers in the US and Japan. Data were analyzed from December 9, 2020, to May 10, 2023. Patients were enrolled in 3 groups according to cancer type: initial diagnosis of non-small cell lung cancer (NSCLC) with an American Joint Committee on Cancer 7th edition T1-3N0M0 tumor (group 1), a T1-3N0M0 new primary NSCLC with a history of prior NSCLC or multiple NSCLCs (group 2), or lung metastases from NSCLC or another solid tumor (group 3). Intervention Up to 4 tumors were treated with once-daily SABR. The dose ranged from 25 Gy in 1 fraction for peripheral tumors with a volume of 0 to 10 cm3 to 60 Gy in 8 fractions for central tumors with a volume greater than 30 cm3. Main outcome Per-group freedom from local recurrence (same-lobe recurrence) at 1 year, with censoring at time of distant recurrence, death, or loss to follow-up. Results In total, 217 unique patients (median [IQR] age, 72 [64-80] years; 129 [59%] male; 150 [69%] current or former smokers) were enrolled (some multiple times). There were 240 treatment courses: 79 in group 1, 82 in group 2, and 79 in group 3. A total of 285 tumors (211 [74%] peripheral and 74 [26%] central) were treated. The most common dose was 25 Gy in 1 fraction (158 tumors). The median (range) follow-up period was 33 (2-109) months, and the median overall survival was 59 (95% CI, 49-82) months. Freedom from local recurrence at 1 year was 97% (90% CI, 91%-99%) for group 1, 94% (90% CI, 87%-97%) for group 2, and 96% (90% CI, 89%-98%) for group 3. Freedom from local recurrence at 5 years ranged from 83% to 93% in the 3 groups. The proportion of patients with grade 3 to 5 toxic effects was low, at 5% (including a single patient [1%] with grade 5 toxic effects). Conclusions and Relevance The results of this nonrandomized controlled trial suggest that individualized SABR (iSABR) used to treat lung tumors may allow minimization of treatment dose and is associated with excellent local control. Individualized dosing should be considered for use in future trials. Trial Registration ClinicalTrials.gov Identifier: NCT01463423.
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Affiliation(s)
- Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Harriet Gee
- Sydney West Radiation Oncology Network, Sydney, New South Wales, Australia
- University of Sydney, Sydney, New South Wales, Australia
| | - Hiroki Shirato
- Department of Radiation Oncology, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Hiroshi Taguchi
- Department of Radiation Oncology, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - John M Snyder
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Alexander L Chin
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Lucas K Vitzthum
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, California
| | - Heather A Wakelee
- Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Joel Neal
- Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Millie Das
- Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Daniel T Chang
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Elizabeth Kidd
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Steven L Hancock
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - David B Shultz
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Kathleen C Horst
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Samantha Wong
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Eleanor Brown
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Ngan Nguyen
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Rachel Liang
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
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Barghouth PG, Melemenidis S, Montay-Gruel P, Ollivier J, Viswanathan V, Jorge PG, Soto LA, Lau BC, Sadeghi C, Edlabadkar A, Zhang R, Ru N, Baulch JE, Manjappa R, Wang J, Le Bouteiller M, Surucu M, Yu A, Bush K, Skinner L, Maxim PG, Loo BW, Limoli CL, Vozenin MC, Frock RL. FLASH-RT does not affect chromosome translocations and junction structures beyond that of CONV-RT dose-rates. Radiother Oncol 2023; 188:109906. [PMID: 37690668 PMCID: PMC10591966 DOI: 10.1016/j.radonc.2023.109906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/12/2023]
Abstract
BACKGROUND AND PURPOSE The impact of radiotherapy (RT) at ultra high vs conventional dose rate (FLASH vs CONV) on the generation and repair of DNA double strand breaks (DSBs) is an important question that remains to be investigated. Here, we tested the hypothesis as to whether FLASH-RT generates decreased chromosomal translocations compared to CONV-RT. MATERIALS AND METHODS We used two FLASH validated electron beams and high-throughput rejoin and genome-wide translocation sequencing (HTGTS-JoinT-seq), employing S. aureus and S. pyogenes Cas9 "bait" DNA double strand breaks (DSBs) in HEK239T cells, to measure differences in bait-proximal repair and their genome-wide translocations to "prey" DSBs generated after various irradiation doses, dose rates and oxygen tensions (normoxic, 21% O2; physiological, 4% O2; hypoxic, 2% and 0.5% O2). Electron irradiation was delivered using a FLASH capable Varian Trilogy and the eRT6/Oriatron at CONV (0.08-0.13 Gy/s) and FLASH (1x102-5x106 Gy/s) dose rates. Related experiments using clonogenic survival and γH2AX foci in the 293T and the U87 glioblastoma lines were also performed to discern FLASH-RT vs CONV-RT DSB effects. RESULTS Normoxic and physioxic irradiation of HEK293T cells increased translocations at the cost of decreasing bait-proximal repair but were indistinguishable between CONV-RT and FLASH-RT. Although no apparent increase in chromosome translocations was observed with hypoxia-induced apoptosis, the combined decrease in oxygen tension with IR dose-rate modulation did not reveal significant differences in the level of translocations nor in their junction structures. Furthermore, RT dose rate modality on U87 cells did not change γH2AX foci numbers at 1- and 24-hours post-irradiation nor did this affect 293T clonogenic survival. CONCLUSION Irrespective of oxygen tension, FLASH-RT produces translocations and junction structures at levels and proportions that are indistinguishable from CONV-RT.
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Affiliation(s)
- Paul G Barghouth
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pierre Montay-Gruel
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland; Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Patrik G Jorge
- Institute of Radiation Physics/CHUV, Lausanne University Hospital, Switzerland
| | - Luis A Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brianna C Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cheyenne Sadeghi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anushka Edlabadkar
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Richard Zhang
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Ning Ru
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Janet E Baulch
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marie Le Bouteiller
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amy Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Richard L Frock
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Ashraf MR, Melemenidis S, Liu K, Velasquez BD, Manjappa R, Soto LA, Dutt S, Skinner L, Yu SJ, Surucu M, Graves EE, Maxim PG, Schueler E, Loo BW. Anatomically Realistic 3D Printed Mouse Phantom for Multi-Institutional Benchmarking of FLASH and CONV Irradiation. Int J Radiat Oncol Biol Phys 2023; 117:e697. [PMID: 37786044 DOI: 10.1016/j.ijrobp.2023.06.2178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) It is reported that about US$28B/year is spent on pre-clinical studies that are not reproducible. FLASH studies may suffer from the same reproducibility crisis due to the non-standard nature of the FLASH beamlines and the lack of dosimeters that can function at ultra-high dose-rates. There have been reports of different outcomes with regard to the FLASH effect across different institutions, even though similar beamlines, temporal structure, and nominal dose levels were used. This brings up the question of the accuracy of dosimetry under FLASH conditions for a fair comparison between FLASH and CONV. To answer this question, we develop and characterize an anatomically realistic 3D-printed mouse phantom to be used in a multi-institutional dosimetric benchmarking effort. MATERIALS/METHODS Mesh files for bony anatomy, lungs, and soft tissue derived from a CT scan of a mouse were converted to an editable 3D model. The 3D model was cut along the coronal plane and modified to allow the inclusion of radiographic film. A multi-material approach was employed to print the phantom. A dual-nozzle 3D printer was used, where one of the nozzles used Acrylonitrile butadiene styrene (ABS) to mimic soft tissue and the other nozzle used Polyactic acid (PLA) to mimic bone density. The two materials were used together in a single print. Lungs were approximated by lightweight PLA and were printed separately and inserted into corresponding cavities in the phantom. Hounsfield Units (HU) and print-to-print stability were verified. Radiographic films were laser cut for different anatomical sites. Two institutes took part in this study with data pending from 3 more institutions. The institutes were instructed to deliver 10 Gy to the plane of the film for the whole abdomen, whole lung, and brain irradiations. 2D dose maps were compared between FLASH and CONV, and the deviation from the prescribed dose was also measured. RESULTS The 3D-printed soft tissue, bone, and lung densities were measured to be ∼ 1.01 g/cc, 1.22 g/cc, and 0.44 g/cc, respectively. For soft tissue and bone, the Hounsfield unit (HU) difference from one print to another was < 10 HU. The greatest variation was within the lungs (54 HU), but this had a minimal effect on the dose distribution (<1%). For the two institutions that completed the survey, the maximum average difference between FLASH and CONV for all irradiations was 0.75 Gy (7.48%). The maximum average difference from the prescribed dose for all irradiations was 0.7 Gy (7.20%) across both institutions. The largest discrepancy was generally observed to be for lung irradiation, indicating that lack of treatment planning systems limits our ability to prescribe accurately in areas of inhomogeneities. CONCLUSION A 3D printed anatomically realistic mouse phantom was developed, characterized, and used in a multi-institutional dosimetric benchmarking effort. Such a study is paramount for the clinical translation of FLASH as it facilitates reduced variability from one institution to another.
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Affiliation(s)
- M R Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, CA
| | - S Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - K Liu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - B D Velasquez
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | | | - L A Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - S Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - L Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - S J Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - M Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - E E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - P G Maxim
- University of California, Irvine, Irvine, CA
| | | | - B W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
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7
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Ashraf MR, Skinner L, Melemenidis S, Dworkin ML, Wu YF, No HJ, Manjappa R, Yu SJ, Surucu M, Graves EE, Maxim PG, Loo BW. Technical Infrastructure for Clinical Translation of Electron FLASH. Int J Radiat Oncol Biol Phys 2023; 117:e639. [PMID: 37785904 DOI: 10.1016/j.ijrobp.2023.06.2046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) For safe clinical translation of electron FLASH, hardware tools for real-time beam control and software tools for treatment planning are necessary. The purpose of this study is to prototype high-throughput hardware for real-time beam control, along with accurate beam modeling of a modern clinical Linac configured to deliver FLASH dose-rates. MATERIALS/METHODS For real-time beam current monitoring, a beam current transformer (BCT) was initially coupled to a fast digitizer and its linearity was established by varying dose per pulse. The radiation pulse width was modified, and this change was measured using the BCT. The BCT was then used to measure the variability of dose per pulse and pulse width due to a mistuned linear accelerator system. Next, the BCT was interfaced with a field programmable gate array (FPGA) which provides the ability for high-throughput and deterministic control of the Linac based on dose accumulation. For beam modeling, the program, TOol for PArticle Simulation (TOPAS), was used to obtain beam parameters by using Bayesian optimization of the beam energy, source size, angular, and energy spread via comparison of simulated and representative dose profiles. The beam model would then be employed to calculate 3D dose distribution in a CT scan of a 3D-printed anatomically realistic mouse phantom. RESULTS The area under the current-time curve from the BCT exhibited excellent linearity (response = 12.80 nC/Gy) up to 2.5 Gy/Pulse (R2 = 0.99). The peak beam current for the electron FLASH beam was measured to be ∼10 mA for an instantaneous dose-rate of ∼5×105 Gy/s. The measured radiation pulse width agreed with the expected value (3.7 μs). The pulse width was then shortened and the measurement by the BCT indicated pulse widths of 1.8 μs and 0.5 μs corresponding to 0.7 Gy/pulse and 0.3 Gy/pulse, respectively. The beamline exhibited a ramp-up in dose per pulse and pulse width when using the automatic frequency controller (AFC). For the first pulse, the dose delivered was ∼0.1-0.3 Gy and the pulse width was 0.6 μs. The output stabilized to nominal values of dose and pulse width after 3-4 pulses. This ramp-up was mitigated by manually tuning the RF resonance with the AFC disabled, after which the BCT exhibited constant output and pulse width. The beam modeling work is in progress. CONCLUSION We demonstrated that a BCT can provide real-time measurement of per-pulse output suitable as input for FLASH beam control based on dose accumulation. The next steps are to quantify the accuracy of the dose control mechanism with the FPGA-based hardware. Potential failure modes will be identified and mitigated in parallel with the development of the hardware. A 3D-printed mouse phantom has been constructed to facilitate beam modeling work for treatment planning (in progress). On completion of this work, it is expected that we will have key infrastructure elements needed to move towards an eventual FDA investigational device exemption for clinical trials.
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Affiliation(s)
- M R Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - L Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - S Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - M L Dworkin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Y F Wu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - H J No
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - R Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - S J Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - M Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - E E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - P G Maxim
- University of California, Irvine, Irvine, CA
| | - B W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA; Stanford Cancer Institute, Stanford, CA
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8
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Ashraf MR, Melemenidis S, Liu K, Grilj V, Jansen J, Velasquez B, Connell L, Schulz JB, Bailat C, Libed A, Manjappa R, Dutt S, Soto L, Lau B, Garza A, Larsen W, Skinner L, Yu AS, Surucu M, Graves EE, Maxim PG, Kry SF, Vozenin MC, Schüler E, Jr BWL. Multi-Institutional Audit of FLASH and Conventional Dosimetry with a 3D-Printed Anatomically Realistic Mouse Phantom. ArXiv 2023:arXiv:2309.16836v1. [PMID: 37808098 PMCID: PMC10557797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
We conducted a multi-institutional audit of dosimetric variability between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3D-printed mouse phantom. A CT scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene ($~1.02 g/cm^3$) and polylactic acid ($~1.24 g/cm^3$) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid ($~0.64 g/cm^3$). Hounsfield units (HU) and densities were compared with the reference CT scan of the live mouse. Print-to-print reproducibility of the phantom was assessed. Three institutions were each provided a phantom, and each institution performed two replicates of irradiations at selected mouse anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. Compared to the reference CT scan, CT scans of the phantom demonstrated mass density differences of $0.10 g/cm^3$ for bone, $0.12 g/cm^3$ for lung, and $0.03 g/cm^3$ for soft tissue regions. Between phantoms, the difference in HU for soft tissue and bone was <10 HU from print to print. Lung exhibited the most variation (54 HU) but minimally affected dose distribution (<0.5% dose differences between phantoms). The mean difference between FLASH and CONV from the first replicate to the second decreased from 4.3% to 1.2%, and the mean difference from the prescribed dose decreased from 3.6% to 2.5% for CONV and 6.4% to 2.7% for FLASH. The framework presented here is promising for credentialing of multi-institutional studies of FLASH preclinical research to maximize the reproducibility of biological findings.
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9
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Gutkin PM, Skinner L, Jiang A, Donaldson SS, Loo BW, Oh J, Wang YP, von Eyben R, Snyder J, Bredfeldt JS, Breneman JC, Constine LS, Faught AM, Haas-Kogan D, Holmes JA, Krasin M, Larkin C, Marcus KJ, Maxim PG, McClelland S, Murphy B, Palmer JD, Perkins SM, Shen CJ, Terezakis S, Bush K, Hiniker SM. Feasibility of the Audio-Visual Assisted Therapeutic Ambience in Radiotherapy (AVATAR) System for Anesthesia Avoidance in Pediatric Patients: A Multicenter Trial. Int J Radiat Oncol Biol Phys 2023; 117:96-104. [PMID: 37001762 DOI: 10.1016/j.ijrobp.2023.03.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/12/2023] [Accepted: 03/22/2023] [Indexed: 05/11/2023]
Abstract
PURPOSE The Audio-Visual Assisted Therapeutic Ambience in Radiotherapy (AVATAR) system was the first published radiation therapy (RT)-compatible system to reduce the need for pediatric anesthesia through video-based distraction. We evaluated the feasibility of AVATAR implementation and effects on anesthesia use, quality of life, and anxiety in a multicenter pediatric trial. METHODS AND MATERIALS Pediatric patients 3 to 10 years of age preparing to undergo RT at 10 institutions were prospectively enrolled. Children able to undergo at least 1 fraction of RT using AVATAR without anesthesia were considered successful (S). Patients requiring anesthesia for their entire treatment course were nonsuccessful (NS). The PedsQL3.0 Cancer Module (PedsQL) survey assessed quality of life and was administered to the patient and guardian at RT simulation, midway through RT, and at final treatment. The modified Yale Preoperative Anxiety Scale (mYPAS) assessed anxiety and was performed at the same 3 time points. Success was evaluated using the χ2 test. PedsQL and mYPAS scores were assessed using mixed effects models with time points evaluated as fixed effects and a random intercept on the subject. RESULTS Eighty-one children were included; median age was 7 years. AVATAR was successful at all 10 institutions and with photon and proton RT. There were 63 (78%) S patients; anesthesia was avoided for a median of 20 fractions per patient. Success differed by age (P = .04) and private versus public insurance (P < .001). Both patient (P = .008) and parent (P = .006) PedsQL scores significantly improved over the course of RT for patients aged 5 to 7. Anxiety in the treatment room decreased for both S and NS patients over RT course (P < .001), by age (P < .001), and by S versus NS patients (P < .001). CONCLUSIONS In this 10-center prospective trial, anesthesia avoidance with AVATAR was 78% in children aged 3 to 10 years, higher than among age-matched historical controls (49%; P < .001). AVATAR implementation is feasible across multiple institutions and should be further studied and made available to patients who may benefit from video-based distraction.
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Affiliation(s)
- Paulina M Gutkin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Medical College of Wisconsin, Wauwatosa, Wisconsin
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Alice Jiang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Sarah S Donaldson
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Justin Oh
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Yi Peng Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - John Snyder
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Jeremy S Bredfeldt
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - John C Breneman
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Louis S Constine
- Department of Radiation Oncology and Pediatrics, James P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York
| | - Austin M Faught
- Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Daphne Haas-Kogan
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Jordan A Holmes
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Matthew Krasin
- Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Charlene Larkin
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Karen J Marcus
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California
| | - Shearwood McClelland
- Departments of Radiation Oncology and Neurologic Surgery, University Hospitals Seidman Cancer Center, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Blair Murphy
- Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon
| | - Joshua D Palmer
- Department of Radiation Oncology, Ohio State University School of Medicine, Columbus, Ohio
| | - Stephanie M Perkins
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
| | - Colette J Shen
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Stephanie Terezakis
- Department of Radiation Oncology, University of Minnesota School of Medicine, Minneapolis, Minnesota
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Susan M Hiniker
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
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Zou W, Zhang R, Schüler E, Taylor PA, Mascia AE, Diffenderfer ES, Zhao T, Ayan AS, Sharma M, Yu SJ, Lu W, Bosch WR, Tsien C, Surucu M, Pollard-Larkin JM, Schuemann J, Moros EG, Bazalova-Carter M, Gladstone DJ, Li H, Simone CB, Petersson K, Kry SF, Maity A, Loo BW, Dong L, Maxim PG, Xiao Y, Buchsbaum JC. Framework for Quality Assurance of Ultrahigh Dose Rate Clinical Trials Investigating FLASH Effects and Current Technology Gaps. Int J Radiat Oncol Biol Phys 2023; 116:1202-1217. [PMID: 37121362 PMCID: PMC10526970 DOI: 10.1016/j.ijrobp.2023.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/28/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023]
Abstract
FLASH radiation therapy (FLASH-RT), delivered with ultrahigh dose rate (UHDR), may allow patients to be treated with less normal tissue toxicity for a given tumor dose compared with currently used conventional dose rate. Clinical trials are being carried out and are needed to test whether this improved therapeutic ratio can be achieved clinically. During the clinical trials, quality assurance and credentialing of equipment and participating sites, particularly pertaining to UHDR-specific aspects, will be crucial for the validity of the outcomes of such trials. This report represents an initial framework proposed by the NRG Oncology Center for Innovation in Radiation Oncology FLASH working group on quality assurance of potential UHDR clinical trials and reviews current technology gaps to overcome. An important but separate consideration is the appropriate design of trials to most effectively answer clinical and scientific questions about FLASH. This paper begins with an overview of UHDR RT delivery methods. UHDR beam delivery parameters are then covered, with a focus on electron and proton modalities. The definition and control of safe UHDR beam delivery and current and needed dosimetry technologies are reviewed and discussed. System and site credentialing for large, multi-institution trials are reviewed. Quality assurance is then discussed, and new requirements are presented for treatment system standard analysis, patient positioning, and treatment planning. The tables and figures in this paper are meant to serve as reference points as we move toward FLASH-RT clinical trial performance. Some major questions regarding FLASH-RT are discussed, and next steps in this field are proposed. FLASH-RT has potential but is associated with significant risks and complexities. We need to redefine optimization to focus not only on the dose but also on the dose rate in a manner that is robust and understandable and that can be prescribed, validated, and confirmed in real time. Robust patient safety systems and access to treatment data will be critical as FLASH-RT moves into the clinical trials.
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Affiliation(s)
- Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Rongxiao Zhang
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Emil Schüler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Paige A Taylor
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Eric S Diffenderfer
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Tianyu Zhao
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Ahmet S Ayan
- Department of Radiation Oncology, Ohio State University, Columbus, OH, USA
| | - Manju Sharma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
| | - Shu-Jung Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Weiguo Lu
- Department of Radiation Oncology, University of Texas Southwestern, Dallas, TX, USA
| | - Walter R Bosch
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Christina Tsien
- Department of Radiation Oncology, McGill University Health Center, Montreal, QC, Canada
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Julianne M Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eduardo G Moros
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | | | - David J Gladstone
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Heng Li
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD, USA
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, NY, USA
| | - Kristoffer Petersson
- Department of Radiation Oncology, MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Amit Maity
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey C Buchsbaum
- Radiation Research Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institute of Health, Bethesda, MD, USA
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11
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Barghouth PG, Melemenidis S, Montay-Gruel P, Ollivier J, Viswanathan V, Jorge PG, Soto LA, Lau BC, Sadeghi C, Edlabadkar A, Manjappa R, Wang J, Le Bouteiller M, Surucu M, Yu A, Bush K, Skinner L, Maxim PG, Loo BW, Limoli CL, Vozenin MC, Frock RL. FLASH-RT does not affect chromosome translocations and junction structures beyond that of CONV-RT dose-rates. bioRxiv 2023:2023.03.27.534408. [PMID: 37034651 PMCID: PMC10081175 DOI: 10.1101/2023.03.27.534408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The molecular and cellular mechanisms driving the enhanced therapeutic ratio of ultra-high dose-rate radiotherapy (FLASH-RT) over slower conventional (CONV-RT) radiotherapy dose-rate remain to be elucidated. However, attenuated DNA damage and transient oxygen depletion are among several proposed models. Here, we tested whether FLASH-RT under physioxic (4% O 2 ) and hypoxic conditions (≤2% O 2 ) reduces genome-wide translocations relative to CONV-RT and whether any differences identified revert under normoxic (21% O 2 ) conditions. We employed high-throughput rejoin and genome-wide translocation sequencing ( HTGTS-JoinT-seq ), using S. aureus and S. pyogenes Cas9 "bait" DNA double strand breaks (DSBs), to measure differences in bait-proximal repair and their genome-wide translocations to "prey" DSBs generated by electron beam CONV-RT (0.08-0.13Gy/s) and FLASH-RT (1×10 2 -5×10 6 Gy/s), under varying ionizing radiation (IR) doses and oxygen tensions. Normoxic and physioxic irradiation of HEK293T cells increased translocations at the cost of decreasing bait-proximal repair but were indistinguishable between CONV-RT and FLASH-RT. Although no apparent increase in chromosome translocations was observed with hypoxia-induced apoptosis, the combined decrease in oxygen tension with IR dose-rate modulation did not reveal significant differences in the level of translocations nor in their junction structures. Thus, Irrespective of oxygen tension, FLASH-RT produces translocations and junction structures at levels and proportions that are indistinguishable from CONV-RT.
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Affiliation(s)
- Paul G. Barghouth
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pierre Montay-Gruel
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Patrik G. Jorge
- Institute of Radiation Physics/CHUV, Lausanne University Hospital, Switzerland
| | - Luis A. Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brianna C. Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cheyenne Sadeghi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anushka Edlabadkar
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marie Le Bouteiller
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amy Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter G. Maxim
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Billy W. Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
| | - Richard L. Frock
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
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12
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Whelan B, Trovati S, Wang J, Fahrig R, Maxim PG, Hanuka A, Shumail M, Tantawi S, Merrick J, Perl J, Keall P, Loo BW. Bayesian optimization to design a novel x-ray shaping device. Med Phys 2022; 49:7623-7637. [PMID: 35904020 DOI: 10.1002/mp.15887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/23/2022] [Accepted: 07/12/2022] [Indexed: 12/27/2022] Open
Abstract
PURPOSE In radiation therapy, x-ray dose must be precisely sculpted to the tumor, while simultaneously avoiding surrounding organs at risk. This requires modulation of x-ray intensity in space and/or time. Typically, this is achieved using a multi leaf collimator (MLC)-a complex mechatronic device comprising over one hundred individually powered tungsten 'leaves' that move in or out of the radiation field as required. Here, an all-electronic x-ray collimation concept with no moving parts is presented, termed "SPHINX": Scanning Pencil-beam High-speed Intensity-modulated X-ray source. SPHINX utilizes a spatially distributed bremsstrahlung target and collimator array in conjunction with magnetic scanning of a high energy electron beam to generate a plurality of small x-ray "beamlets." METHODS A simulation framework was developed in Topas Monte Carlo incorporating a phase space electron source, transport through user defined magnetic fields, bremsstrahlung x-ray production, transport through a SPHINX collimator, and dose in water. This framework was completely parametric, meaning a simulation could be built and run for any supplied geometric parameters. This functionality was coupled with Bayesian optimization to find the best parameter set based on an objective function which included terms to maximize dose rate for a user defined beamlet width while constraining inter-channel cross talk and electron contamination. Designs for beamlet widths of 5, 7, and 10 mm2 were generated. Each optimization was run for 300 iterations and took approximately 40 h on a 24-core computer. For the optimized 7-mm model, a simulation of all beamlets in water was carried out including a linear scanning magnet calibration simulation. Finally, a back-of-envelope dose rate formalism was developed and used to estimate dose rate under various conditions. RESULTS The optimized 5-, 7-, and 10-mm models had beamlet widths of 5.1 , 7.2 , and 10.1 mm2 and dose rates of 3574, 6351, and 10 015 Gy/C, respectively. The reduction in dose rate for smaller beamlet widths is a result of both increased collimation and source occlusion. For the simulation of all beamlets in water, the scanning magnet calibration reduced the offset between the collimator channels and beam centroids from 2.9 ±1.9 mm to 0.01 ±0.03 mm. A slight reduction in dose rate of approximately 2% per degree of scanning angle was observed. Based on a back-of-envelope dose rate formalism, SPHINX in conjunction with next-generation linear accelerators has the potential to achieve substantially higher dose rates than conventional MLC-based delivery, with delivery of an intensity modulated 100 × 100 mm2 field achievable in 0.9 to 10.6 s depending on the beamlet widths used. CONCLUSIONS Bayesian optimization was coupled with Monte Carlo modeling to generate SPHINX geometries for various beamlet widths. A complete Monte Carlo simulation for one of these designs was developed, including electron beam transport of all beamlets through scanning magnets, x-ray production and collimation, and dose in water. These results demonstrate that SPHINX is a promising candidate for sculpting radiation dose with no moving parts, and has the potential to vastly improve both the speed and robustness of radiotherapy delivery. A multi-beam SPHINX system may be a candidate for delivering magavoltage FLASH RT in humans.
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Affiliation(s)
- Brendan Whelan
- ACRF Image-X Institute, School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, Australia.,Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA
| | - Stefania Trovati
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA.,Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA.,Varian Medical Systems, Palo Alto, California, USA
| | - Rebecca Fahrig
- Innovation, Advanced Therapies, Siemens Healthineers, Forchheim, Germany.,Department of Computer Science 5, Friedrich-Alexander Universitat, Erlangen, Germany
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California, USA
| | - Adi Hanuka
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Muhammad Shumail
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Sami Tantawi
- SLAC National Accelerator Laboratory, Menlo Park, California, USA.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California, USA
| | - Julian Merrick
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Joseph Perl
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Paul Keall
- ACRF Image-X Institute, School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California, USA.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California, USA
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13
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Jorge PG, Melemenidis S, Grilj V, Buchillier T, Manjappa R, Viswanathan V, Gondré M, Vozenin MC, Germond JF, Bochud F, Moeckli R, Limoli C, Skinner L, No HJ, Wu YF, Surucu M, Yu AS, Lau B, Wang J, Schüler E, Bush K, Graves EE, Maxim PG, Loo BW, Bailat C. Design and validation of a dosimetric comparison scheme tailored for ultra-high dose-rate electron beams to support multicenter FLASH preclinical studies. Radiother Oncol 2022; 175:203-209. [PMID: 36030934 DOI: 10.1016/j.radonc.2022.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE We describe a multicenter cross validation of ultra-high dose rate (UHDR) (>= 40 Gy/s) irradiation in order to bring a dosimetric consensus in absorbed dose to water. UHDR refers to dose rates over 100-1000 times those of conventional clinical beams. UHDR irradiations have been a topic of intense investigation as they have been reported to induce the FLASH effect in which normal tissues exhibit reduced toxicity relative to conventional dose rates. The need to establish optimal beam parameters capable of achieving the in vivo FLASH effect has become paramount. It is therefore necessary to validate and replicate dosimetry across multiple sites conducting UHDR studies with distinct beam configurations and experimental set-ups. MATERIALS AND METHODS Using a custom cuboid phantom with a cylindrical cavity (5 mm diameter by 10.4 mm length) designed to contain three type of dosimeters (thermoluminescent dosimeters (TLDs), alanine pellets, and Gafchromic films), irradiations were conducted at expected doses of 7.5 to 16 Gy delivered at UHDR or conventional dose rates using various electron beams at the Radiation Oncology Departments of the CHUV in Lausanne, Switzerland and Stanford University, CA. RESULTS Data obtained between replicate experiments for all dosimeters were in excellent agreement (±3%). In general, films and TLDs were in closer agreement with each other, while alanine provided the closest match between the expected and measured dose, with certain caveats related to absolute reference dose. CONCLUSION In conclusion, successful cross-validation of different electron beams operating under different energies and configurations lays the foundation for establishing dosimetric consensus for UHDR irradiation studies, and, if widely implemented, decrease uncertainty between different sites investigating the mechanistic basis of the FLASH effect.
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Affiliation(s)
- Patrik Gonçalves Jorge
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Thierry Buchillier
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Maude Gondré
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- CHUV - Radiation-oncology Laboratory, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles Limoli
- Department of Radiation Oncology, University of California, Irvine, CA 92697, USA
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hyunsoo Joshua No
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yufan Fred Wu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Emil Schüler
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, CA 92697, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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14
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Schüler E, Acharya M, Montay-Gruel P, Loo BW, Vozenin MC, Maxim PG. Ultra-high dose rate electron beams and the FLASH effect: From preclinical evidence to a new radiotherapy paradigm. Med Phys 2022; 49:2082-2095. [PMID: 34997969 PMCID: PMC9032195 DOI: 10.1002/mp.15442] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/14/2021] [Accepted: 12/17/2021] [Indexed: 12/30/2022] Open
Abstract
In their seminal paper from 2014, Fauvadon et al. coined the term FLASH irradiation to describe ultra-high-dose rate irradiation with dose rates greater than 40 Gy/s, which results in delivery times of fractions of a second. The experiments presented in that paper were performed with a high-dose-per-pulse 4.5 MeV electron beam, and the results served as the basis for the modern-day field of FLASH radiation therapy (RT). In this article, we review the studies that have been published after those early experiments, demonstrating the robust effects of FLASH RT on normal tissue sparing in preclinical models. We also outline the various irradiation parameters that have been used. Although the robustness of the biological response has been established, the mechanisms behind the FLASH effect are currently under investigation in a number of laboratories. However, differences in the magnitude of the FLASH effect between experiments in different labs have been reported. Reasons for these differences even within the same animal model are currently unknown, but likely has to do with the marked differences in irradiation parameter settings used. Here, we show that these parameters are often not reported, which complicates large multistudy comparisons. For this reason, we propose a new standard for beam parameter reporting and discuss a systematic path to the clinical translation of FLASH RT.
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Affiliation(s)
- Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA,Graduate School of Biomedical Sciences, The University of Texas, Houston, TX 77030 USA
| | - Munjal Acharya
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
| | - Billy W. Loo
- Department of Radiation Oncology and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland,Corresponding authors: Peter G. Maxim, PhD, Department of Radiation Oncology, University of California, Irvine, Irvine, CA 713-563-4019, , Marie-Catherine Vozenin, PhD, Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Switzerland. +41 216925901,
| | - Peter G. Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA,Corresponding authors: Peter G. Maxim, PhD, Department of Radiation Oncology, University of California, Irvine, Irvine, CA 713-563-4019, , Marie-Catherine Vozenin, PhD, Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Switzerland. +41 216925901,
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15
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Guerrieri P, Jacob NK, Maxim PG, Sawant A, Van Nest SJ, Mohindra P, Dominello MM, Burmeister JW, Joiner MC. Three discipline collaborative radiation therapy (3DCRT) special debate: FLASH radiotherapy needs ongoing basic and animal research before implementing it to a large clinical scale. J Appl Clin Med Phys 2022; 23:e13547. [PMID: 35104025 PMCID: PMC8992943 DOI: 10.1002/acm2.13547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 11/15/2022] Open
Affiliation(s)
- Patrizia Guerrieri
- Department of Radiation Oncology, Bon Secours Mercy Health, Youngstown, Ohio, USA
| | | | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California, USA
| | - Amit Sawant
- Department of Radiation Oncology, University of Maryland, Baltimore, Maryland, USA.,Maryland Proton Treatment Center, Baltimore, Maryland, USA
| | - Samantha J Van Nest
- Department of Radiation Oncology, Weill Cornell Medicine, New York, New York, USA
| | - Pranshu Mohindra
- Department of Radiation Oncology, University of Maryland, Baltimore, Maryland, USA.,Maryland Proton Treatment Center, Baltimore, Maryland, USA
| | | | - Jay W Burmeister
- Department of Oncology, Wayne State University, Detroit, Michigan, USA.,Gershenson Radiation Oncology Center, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan, USA
| | - Michael C Joiner
- Department of Oncology, Wayne State University, Detroit, Michigan, USA
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16
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Sodji QH, Harris JP, Quon A, Modlin LA, Lau B, Jiang A, Trakul N, Maxim PG, Diehn M, Loo BW, Hiniker SM. Detection of Recurrence after Thoracic Stereotactic Ablative Radiotherapy Using FDG-PET-CT. Clin Lung Cancer 2022; 23:282-289. [DOI: 10.1016/j.cllc.2022.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/10/2022] [Accepted: 01/17/2022] [Indexed: 11/29/2022]
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17
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Sodji QH, Ko R, von Eyben R, Owen SG, Capaldi DPI, Bush K, Binkley MS, Alrowais F, Pickthorn B, Maxim PG, Gensheimer MF, Diehn M, Loo BW. Acute and Late Esophageal Toxicity Following Stereotactic Ablative Radiotherapy to Thoracic Tumors near or Abutting the Esophagus. Int J Radiat Oncol Biol Phys 2021; 112:1144-1153. [PMID: 34942312 DOI: 10.1016/j.ijrobp.2021.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/29/2021] [Accepted: 12/08/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the incidence of acute and late esophageal toxicity in patients with thoracic tumors near or abutting the esophagus treated with stereotactic ablative radiotherapy (SABR). METHODS AND MATERIALS Among patients with thoracic tumors treated with SABR, we identified those with tumors near or abutting the esophagus. Using the linear-quadratic model with an α/ß ratio of 10, we determined the correlation between dosimetric parameters and esophageal toxicity graded using the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. RESULTS Out of 2200 patients treated with thoracic SABR, 767 patients were analyzable for esophageal dosimetry. We identified 55 patients with tumors near the esophagus (52 evaluable for esophagitis grade), 28 with PTV overlapping the esophagus. Median follow-up and overall survival were 16 and 23 months respectively. Thirteen patients (25%) developed temporary grade 2 acute esophageal toxicity, 11 (85%) of whom had PTV overlapping the esophagus. Symptoms resolved within 1-3 months in 12 patients, and 6 months in all patients. No grade 3-5 toxicity was observed. Only 3 patients (6%) developed late or persistent grade 2 dysphagia or dyspepsia of uncertain relationship to SABR. Cumulative incidence of acute esophagitis was 15% and 25% at 14 days and 60 days respectively. Acute toxicity correlated on univariate analysis with esophageal Dmax, D1cc, D2cc, Dmax/Dprescription and whether the PTV was overlapping the esophagus. Esophageal Dmax (BED10) < 62 Gy, D1cc (BED10) < 48 Gy, D2cc (BED10) < 43 Gy, and Dmax/Dprescription < 85% was associated with <20% risk of grade 2 acute esophagitis. Only 2 local recurrences occurred. CONCLUSIONS Although 25% of patients with tumors near the esophagus developed acute esophagitis (39% of those with PTV overlapping the esophagus), these toxicities were all grade 2 and all temporary. This suggests the safety and efficacy of thoracic SABR for tumors near or abutting the esophagus when treating with high conformity and sharp dose gradients.
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Affiliation(s)
- Quaovi H Sodji
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Ryan Ko
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A..
| | - Susie G Owen
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Dante P I Capaldi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Michael S Binkley
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Fahad Alrowais
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Bill Pickthorn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine, CA, U.S.A
| | - Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, U.S.A
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, U.S.A.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, U.S.A.
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18
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Benson KRK, Sandhu N, Zhang C, Ko R, Toesca DAS, Lee PE, Von Eyben R, Diehn M, Gensheimer M, Maxim PG, Bush K, Loo BW, Soltys SG, Pollom EL, Chang DT. Local Recurrence Outcomes of Colorectal Cancer Oligometastases Treated With Stereotactic Ablative Radiotherapy. Am J Clin Oncol 2021; 44:559-564. [PMID: 34534143 DOI: 10.1097/coc.0000000000000864] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE The aim of this study was to report local failure (LF) outcomes and associated predictors in patients with oligometastatic colorectal cancer (CRC) treated with stereotactic ablative radiotherapy (SABR). MATERIALS AND METHODS We retrospectively reviewed patients with CRC metastases to the brain, liver, spine, or lung treated with SABR between 2001 and 2016. Time to LF was summarized using cumulative incidence of LF curves with death as a competing risk. RESULTS The analysis included a total of 130 patients and 256 lesions. Of the metastases treated, 129 (50%) were brain, 50 (20%) liver, 49 (19%) spine, and 28 (11%) lung. Median gross tumor volume was 24 mL for liver metastases, 2 mL for brain metastases, 4 mL for spine metastases, and 1 mL for lung metastases. The overall 1, 2, and 3-year cumulative incidence of LF rates were 21.6% (16.5, 27.1), 28.2% (22.3, 34.4), and 31.5% (25.2, 38.0), respectively. LF was highest among the liver metastases (1 y: 26.0%, 2 y: 38.5%), followed by spine (1 y: 25.1%, 2 y: 31.1%), brain (1 y: 20%, 2 y: 25.2%), and lung (1 y: 13.7%, 2 y: insufficient data). Metastases from right-sided primary CRC were significantly more likely to have LF (P=0.0146, HR=2.23). Biologically effective dose>70 Gy, defined using a standard linear quadratic model using α/β ratio of 10 on the individual lesion level, and pre-SABR chemotherapy were also significant predictors of LF (P= 0.0009 and 0.018, respectively). CONCLUSIONS CRC metastases treated with SABR had significantly higher rates of LF if they originated from right-sided primary CRC, compared with left-sided. Liver metastases had the highest rates of LF compared with other metastatic sites. Thus, CRC liver metastases and metastases from right-sided CRC may benefit from more aggressive radiotherapy.
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Affiliation(s)
- Kathryn R K Benson
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Navjot Sandhu
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Carrie Zhang
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Ryan Ko
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Diego A S Toesca
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Phoebe E Lee
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Rie Von Eyben
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Michael Gensheimer
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN
| | - Karl Bush
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Scott G Soltys
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Erqi L Pollom
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
| | - Daniel T Chang
- Department of Radiation Oncology, Stanford Cancer Institute, Stanford, CA
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19
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Poirier Y, Mossahebi S, Becker SJ, Koger B, Xu J, Lamichhane N, Maxim PG, Sawant A. Radiation shielding and safety implications following linac conversion to an electron FLASH-RT unit. Med Phys 2021; 48:5396-5405. [PMID: 34287938 DOI: 10.1002/mp.15105] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/03/2021] [Accepted: 07/12/2021] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Due to their finite range, electrons are typically ignored when calculating shielding requirements in megavoltage energy linear accelerator vaults. However, the assumption that 16 MeV electrons need not be considered does not hold when operated at FLASH-RT dose rates (~200× clinical dose rate), where dose rate from bremsstrahlung photons is an order of magnitude higher than that from an 18 MV beam for which shielding was designed. We investigate the shielding and radiation protection impact of converting a Varian 21EX linac to FLASH-RT dose rates. METHODS We performed a radiation survey in all occupied areas using a Fluke Biomedical Inovision 451P survey meter and a Wide Energy Neutron Detection Instrument (Wendi)-2 FHT 762 neutron detector. The dose rate from activated linac components following a 1.8-min FLASH-RT delivery was also measured. RESULTS When operated at a gantry angle of 180° such as during biology experiments, the 16 MeV FLASH-RT electrons deliver ~10 µSv/h in the controlled areas and 780 µSv/h in the uncontrolled areas, which is above the 20 µSv in any 1-h USNRC limit. However, to exceed 20 µSv, the unit must be operated continuously for 92 s, which corresponds in this bunker and FLASH-RT beam to a 3180 Gy workload at isocenter, which would be unfeasible to deliver within that timeframe due to experimental logistics. While beam steering and dosimetry activities can require workloads of that magnitude, during these activities, the gantry is positioned at 0° and the dose rate in the uncontrolled area becomes undetectable. Likewise, neutron activation of linac components can reach 25 µSv/h near the isocenter following FLASH-RT delivery, but dissipates within minutes, and total doses within an hour are below 20 µSv. CONCLUSION Bremsstrahlung photons created by a 16 MeV FLASH-RT electron beam resulted in consequential dose rates in controlled and uncontrolled areas, and from activated linac components in the vault. While our linac vault shielding proved sufficient, other investigators would be prudent to confirm the adequacy of their radiation safety program, particularly if operating in vaults designed for 6 MV.
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Affiliation(s)
- Yannick Poirier
- University of Maryland School of Medicine, Baltimore, MD, USA.,McGill University, Montreal, QC, Canada
| | - Sina Mossahebi
- University of Maryland School of Medicine, Baltimore, MD, USA
| | | | | | - Junliang Xu
- University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Peter G Maxim
- University of California Irvine, School of Medicine, Irvine, CA, USA
| | - Amit Sawant
- University of Maryland School of Medicine, Baltimore, MD, USA
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20
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Soto LA, Casey KM, Wang J, Blaney A, Manjappa R, Breitkreutz D, Skinner L, Dutt S, Ko RB, Bush K, Yu AS, Melemenidis S, Strober S, Englemann E, Maxim PG, Graves EE, Loo BW. FLASH Irradiation Results in Reduced Severe Skin Toxicity Compared to Conventional-Dose-Rate Irradiation. Radiat Res 2021; 194:618-624. [PMID: 32853385 DOI: 10.1667/rade-20-00090] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/18/2020] [Indexed: 01/08/2023]
Abstract
Radiation therapy, along with surgery and chemotherapy, is one of the main treatments for cancer. While radiotherapy is highly effective in the treatment of localized tumors, its main limitation is its toxicity to normal tissue. Previous preclinical studies have reported that ultra-high dose-rate (FLASH) irradiation results in reduced toxicity to normal tissues while controlling tumor growth to a similar extent relative to conventional-dose-rate (CONV) irradiation. To our knowledge this is the first report of a dose-response study in mice comparing the effect of FLASH irradiation vs. CONV irradiation on skin toxicity. We found that FLASH irradiation results in both a lower incidence and lower severity of skin ulceration than CONV irradiation 8 weeks after single-fraction hemithoracic irradiation at high doses (30 and 40 Gy). Survival was also higher after FLASH hemithoracic irradiation (median survival >180 days at doses of 30 and 40 Gy) compared to CONV irradiation (median survival 100 and 52 days at 30 and 40 Gy, respectively). No ulceration was observed at doses 20 Gy or below in either FLASH or CONV. These results suggest a shifting of the dose-response curve for radiation-induced skin ulceration to the right for FLASH, compared to CONV irradiation, suggesting the potential for an enhanced therapeutic index for radiation therapy of cancer.
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Affiliation(s)
- Luis A Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305.,Cancer Biology Program, Stanford University School of Medicine, Stanford, California 94305
| | - Kerriann M Casey
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California 94305
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Alexandra Blaney
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California 94305
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Dylan Breitkreutz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305.,Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305
| | - Ryan B Ko
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
| | - Samuel Strober
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Edgar Englemann
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305.,Department of Pathology, Stanford University School of Medicine, Stanford, California 94305
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305.,Department of Pathology, Stanford University School of Medicine, Stanford, California 94305
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305.,Department of Pathology, Stanford University School of Medicine, Stanford, California 94305
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21
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Ko RB, Soto LA, von Eyben R, Melemenidis S, Rankin EB, Maxim PG, Graves EE, Loo BW. Evaluating the Reproducibility of Mouse Anatomy under Rotation in a Custom Immobilization Device for Conformal FLASH Radiotherapy. Radiat Res 2021; 194:600-606. [PMID: 32857849 DOI: 10.1667/rade-20-00095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/18/2020] [Indexed: 11/03/2022]
Abstract
The observation of an enhanced therapeutic index for FLASH radiotherapy in mice has created interest in practical laboratory-based FLASH irradiators. To date, systems capable of 3D conformal FLASH irradiation in mice have been lacking. We are developing such a system, incorporating a high-current linear accelerator to produce a collimated X-ray beam in a stationary beamline design, rotating the mouse about a longitudinal axis to achieve conformal irradiation from multiple beam directions. The purpose of this work was to evaluate the reproducibility of mouse anatomy under rotation at speeds compatible with conformal FLASH delivery. Three short-hair mice and two hairless mice were immobilized under anesthesia in body weight-specific contoured plastic molds, and subjected to three rotational (up to 3 revolutions/s) and two non-rotational movement interventions. MicroCT images were acquired before and after each intervention. The displacements of 11 anatomic landmarks were measured on the image pairs. The displacement of the anatomical landmarks with any of the interventions was 0.5 mm or less for 92.4% of measurements, with a single measurement out of 275 (11 landmarks × 5 interventions × 5 mice) reaching 1 mm. There was no significant difference in the displacements associated with rotation compared to those associated with moving the immobilized mouse in and out of a scanner or with leaving the mouse in place for 5 min with no motion. There were no significant differences in displacements between mice with or without hair, although the analysis is limited by small numbers, or between different anatomic landmarks. These results show that anatomic reproducibility under rotation speed corresponding to FLASH irradiation times appears to be compatible with conformal/stereotactic irradiation in mice.
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Affiliation(s)
- Ryan B Ko
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis A Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
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22
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Wang J, Wang L, Maxim PG, Loo BW. An automated optimization strategy to design collimator geometry for small field radiation therapy systems. Phys Med Biol 2021; 66. [PMID: 33657538 DOI: 10.1088/1361-6560/abeba9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/03/2021] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop an automated optimization strategy to facilitate collimator design for small-field radiotherapy systems. METHODS We developed an objective function that links the dose profile characteristics (FWHM, penumbra, and central dose rate) and the treatment head geometric parameters (collimator thickness/radii, source-to-distal-collimator distance[SDC]) for small-field radiotherapy systems. We performed optimization using a downhill simplex algorithm. We applied this optimization strategy to a linac-based radiosurgery system to determine the optimal geometry of four pencil-beam collimators to produce 5, 10, 15, and 20mm diameter photon beams (from a 6.7MeV, 2.1mmFWHM electron beam). Two different optimizations were performed to prioritize minimum penumbra or maximum central dose rate for each beam size. We compared the optimized geometric parameters and dose distributions to an existing clinical system (CyberKnife). RESULTS When minimum penumbra was prioritized, using the same collimator thickness and SDC (40cm) as a CyberKnife system, the optimized collimator upstream and downstream radii agreed with the CyberKnife system within 3-14%, the optimized output factors agreed within 0-8%, and the optimized transverse and percentage depth dose profiles matched those of the CyberKnife with the penumbras agreeing within 2%. However, when maximum dose rate was prioritized, allowing both the collimator thickness and SDC to change, the central dose rate for larger collimator sizes (10, 15, 20mm) could be increased by about 1.5-2 times at the cost of 1.5-2 times larger penumbras. No further improvement in central dose rate for the 5mm beam size could be achieved. CONCLUSIONS We developed an automated optimization strategy to design the collimator geometry for small-field radiation therapy systems. Using this strategy, the penumbra-prioritized dose distribution and geometric parameters agree well with the CyberKnife system as an example, suggesting that this system was designed to prioritize sharp penumbra. This represents proof-of-principle that an automated optimization strategy may apply to more complex collimator designs with multiple optimization parameters.
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Affiliation(s)
- Jinghui Wang
- Radiation Oncology, Stanford University School of Medicine, Stanford, California, UNITED STATES
| | - Lei Wang
- Radiation Oncology, Stanford University School of Medicine, Stanford, California, UNITED STATES
| | - Peter G Maxim
- Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana, UNITED STATES
| | - Billy W Loo
- Radiation Oncology, Stanford University School of Medicine, Stanford, California, UNITED STATES
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23
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Khan S, Bassenne M, Wang J, Manjappa R, Melemenidis S, Breitkreutz DY, Maxim PG, Xing L, Loo BW, Pratx G. Multicellular Spheroids as In Vitro Models of Oxygen Depletion During FLASH Irradiation. Int J Radiat Oncol Biol Phys 2021; 110:833-844. [PMID: 33545301 DOI: 10.1016/j.ijrobp.2021.01.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 12/15/2020] [Accepted: 01/26/2021] [Indexed: 12/15/2022]
Abstract
PURPOSE The differential response of normal and tumor tissues to ultrahigh-dose-rate radiation (FLASH) has raised new hope for treating solid tumors but, to date, the mechanism remains elusive. One leading hypothesis is that FLASH radiochemically depletes oxygen from irradiated tissues faster than it is replenished through diffusion. The purpose of this study was to investigate these effects within hypoxic multicellular tumor spheroids through simulations and experiments. METHODS AND MATERIALS Physicobiological equations were derived to model (1) the diffusion and metabolism of oxygen within spheroids; (2) its depletion through reactions involving radiation-induced radicals; and (3) the increase in radioresistance of spheroids, modeled according to the classical oxygen enhancement ratio and linear-quadratic response. These predictions were then tested experimentally in A549 spheroids exposed to electron irradiation at conventional (0.075 Gy/s) or FLASH (90 Gy/s) dose rates. Clonogenic survival, cell viability, and spheroid growth were scored postradiation. Clonogenic survival of 2 other cell lines was also investigated. RESULTS The existence of a hypoxic core in unirradiated tumor spheroids is predicted by simulations and visualized by fluorescence microscopy. Upon FLASH irradiation, this hypoxic core transiently expands, engulfing a large number of well-oxygenated cells. In contrast, oxygen is steadily replenished during slower conventional irradiation. Experimentally, clonogenic survival was around 3-fold higher in FLASH-irradiated spheroids compared with conventional irradiation, but no significant difference was observed for well-oxygenated 2-dimensional cultured cells. This differential survival is consistent with the predictions of the computational model. FLASH irradiation of spheroids resulted in a dose-modifying factor of around 1.3 for doses above 10 Gy. CONCLUSIONS Tumor spheroids can be used as a model to study FLASH irradiation in vitro. The improved survival of tumor spheroids receiving FLASH radiation confirms that ultrafast radiochemical oxygen depletion and its slow replenishment are critical components of the FLASH effect.
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Affiliation(s)
- Syamantak Khan
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Maxime Bassenne
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University, Stanford, California
| | | | | | - Peter G Maxim
- Department of Radiation Oncology, Indiana University, Indianapolis, Indiana
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Guillem Pratx
- Department of Radiation Oncology, Stanford University, Stanford, California.
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24
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Arbab M, Bartlett G, DesRosiers C, Maxim PG, Lautenschlaeger T. Early‐stage lung adenocarcinoma treated with stereotactic body radiation therapy using a combined deep inspiration breath hold and free breathing technique: case report and literature review. Prec Radiat Oncol 2020. [DOI: 10.1002/pro6.1101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Mona Arbab
- Department of Radiation Oncology Radiation Oncology Indiana University Health Indianapolis Indiana USA
| | - Gregory Bartlett
- Department of Radiation Oncology Radiation Oncology Indiana University Health Indianapolis Indiana USA
| | - Colleen DesRosiers
- Department of Radiation Oncology Radiation Oncology Indiana University Health Indianapolis Indiana USA
| | - Peter G Maxim
- Department of Radiation Oncology Radiation Oncology Indiana University Health Indianapolis Indiana USA
| | - Tim Lautenschlaeger
- Department of Radiation Oncology Radiation Oncology Indiana University Health Indianapolis Indiana USA
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25
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Binkley MS, Jeon YJ, Nesselbush M, Moding EJ, Nabet BY, Almanza D, Kunder C, Stehr H, Yoo CH, Rhee S, Xiang M, Chabon JJ, Hamilton E, Kurtz DM, Gojenola L, Owen SG, Ko RB, Shin JH, Maxim PG, Lui NS, Backhus LM, Berry MF, Shrager JB, Ramchandran KJ, Padda SK, Das M, Neal JW, Wakelee HA, Alizadeh AA, Loo BW, Diehn M. KEAP1/NFE2L2 Mutations Predict Lung Cancer Radiation Resistance That Can Be Targeted by Glutaminase Inhibition. Cancer Discov 2020; 10:1826-1841. [PMID: 33071215 PMCID: PMC7710558 DOI: 10.1158/2159-8290.cd-20-0282] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 08/12/2020] [Accepted: 09/16/2020] [Indexed: 11/16/2022]
Abstract
Tumor genotyping is not routinely performed in localized non-small cell lung cancer (NSCLC) due to lack of associations of mutations with outcome. Here, we analyze 232 consecutive patients with localized NSCLC and demonstrate that KEAP1 and NFE2L2 mutations are predictive of high rates of local recurrence (LR) after radiotherapy but not surgery. Half of LRs occurred in tumors with KEAP1/NFE2L2 mutations, indicating that they are major molecular drivers of clinical radioresistance. Next, we functionally evaluate KEAP1/NFE2L2 mutations in our radiotherapy cohort and demonstrate that only pathogenic mutations are associated with radioresistance. Furthermore, expression of NFE2L2 target genes does not predict LR, underscoring the utility of tumor genotyping. Finally, we show that glutaminase inhibition preferentially radiosensitizes KEAP1-mutant cells via depletion of glutathione and increased radiation-induced DNA damage. Our findings suggest that genotyping for KEAP1/NFE2L2 mutations could facilitate treatment personalization and provide a potential strategy for overcoming radioresistance conferred by these mutations. SIGNIFICANCE: This study shows that mutations in KEAP1 and NFE2L2 predict for LR after radiotherapy but not surgery in patients with NSCLC. Approximately half of all LRs are associated with these mutations and glutaminase inhibition may allow personalized radiosensitization of KEAP1/NFE2L2-mutant tumors.This article is highlighted in the In This Issue feature, p. 1775.
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Affiliation(s)
- Michael S Binkley
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Young-Jun Jeon
- Stanford Cancer Institute, Stanford, California
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea
| | | | - Everett J Moding
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Barzin Y Nabet
- Department of Radiation Oncology, Stanford University, Stanford, California
- Stanford Cancer Institute, Stanford, California
| | - Diego Almanza
- Cancer Biology Program, Stanford University, Stanford, California
| | - Christian Kunder
- Department of Pathology, Stanford University, Stanford, California
| | - Henning Stehr
- Department of Pathology, Stanford University, Stanford, California
| | - Christopher H Yoo
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Siyeon Rhee
- Department of Biology, Stanford University, Stanford, California
| | - Michael Xiang
- Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, California
| | | | - Emily Hamilton
- Cancer Biology Program, Stanford University, Stanford, California
| | - David M Kurtz
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Linda Gojenola
- Department of Pathology, Stanford University, Stanford, California
| | - Susie Grant Owen
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Ryan B Ko
- Department of Radiation Oncology, Stanford University, Stanford, California
| | | | - Peter G Maxim
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Natalie S Lui
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California
| | - Leah M Backhus
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California
| | - Mark F Berry
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California
| | - Joseph B Shrager
- Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California
| | - Kavitha J Ramchandran
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Sukhmani K Padda
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Millie Das
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Joel W Neal
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Heather A Wakelee
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Ash A Alizadeh
- Stanford Cancer Institute, Stanford, California
- Division of Oncology, Department of Medicine, Stanford University, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, Stanford, California
- Stanford Cancer Institute, Stanford, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University, Stanford, California.
- Stanford Cancer Institute, Stanford, California
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California
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26
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Kim YE, Gwak SH, Hong BJ, Oh JM, Choi HS, Kim MS, Oh D, Lartey FM, Rafat M, Schüler E, Kim HS, von Eyben R, Weissman IL, Koch CJ, Maxim PG, Loo BW, Ahn GO. Effects of Ultra-high doserate FLASH Irradiation on the Tumor Microenvironment in Lewis Lung Carcinoma: Role of Myosin Light Chain. Int J Radiat Oncol Biol Phys 2020; 109:1440-1453. [PMID: 33186615 DOI: 10.1016/j.ijrobp.2020.11.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To investigate whether the vascular collapse in tumors by conventional dose rate (CONV) irradiation (IR) would also occur by the ultra-high dose rate FLASH IR. METHODS AND MATERIALS Lewis lung carcinoma (LLC) cells were subcutaneously implanted in mice. This was followed by CONV or FLASH IR at 15 Gy. Tumors were harvested at 6 or 48 hours after IR and stained for CD31, phosphorylated myosin light chain (p-MLC), γH2AX (a surrogate marker for DNA double strand break), intracellular reactive oxygen species (ROS), or immune cells such as myeloid and CD8α T cells. Cell lines were irradiated with CONV IR for Western blot analyses. ML-7 was intraperitoneally administered daily to LLC-bearing mice for 7 days before 15 Gy CONV IR. Tumors were similarly harvested and analyzed. RESULTS By immunostaining, we observed that CONV IR at 6 hours resulted in constricted vessel morphology, increased expression of p-MLC, and much higher numbers of γH2AX-positive cells in tumors, which were not observed with FLASH IR. Mechanistically, MLC activation by ROS is unlikely, because FLASH IR produced significantly more ROS than CONV IR in tumors. In vitro studies demonstrated that ML-7, an inhibitor of MLC kinase, abrogated IR-induced γH2AX formation and disappearance kinetics. Lastly, we observed that CONV IR when combined with ML-7 produced some effects similar to FLASH IR, including reduction in the vasculature collapse, fewer γH2AX-positive cells, and increased immune cell influx to the tumors. CONCLUSIONS FLASH IR produced novel changes in the tumor microenvironment that were not observed with CONV IR. We believe that MLC activation in tumors may be responsible for some of the microenvironmental changes differentially regulated between CONV and FLASH IR.
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Affiliation(s)
- Young-Eun Kim
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Seung-Hee Gwak
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Beom-Ju Hong
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Gyeongbuk, Korea
| | - Jung-Min Oh
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Gyeongbuk, Korea
| | - Hyung-Seok Choi
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Myeoung Su Kim
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Dawit Oh
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Frederik M Lartey
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Marjan Rafat
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Emil Schüler
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Hyo-Soo Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Irving L Weissman
- Institute of Stem Cell and Regenerative Medicine, Stanford University School of Medicine, Stanford, California
| | - Cameron J Koch
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - G-One Ahn
- College of Veterinary Medicine, Seoul National University, Seoul, Korea.
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27
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Natarajan S, Levy K, Wang J, Chow S, Eggold J, Loo P, Manjappa R, Lartey FM, Schüler E, Skinner L, Rafat M, Ko R, Kim A, Rawi DA, von Eyben R, Dorigo O, Casey KM, Graves EE, Bush K, Yu AS, Koong AC, Maxim PG, Loo BW, Rankin EB. Abstract 5351: FLASH irradiation enhances the therapeutic index of abdominal radiotherapy in mice. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-5351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Radiation therapy is the most effective cytotoxic cancer therapy available for the treatment of localized tumors. However, radiation-induced toxicity to normal tissues limits the radiation dose and therefore the curative potential of radiotherapy. In particular, the highly radiosensitive intestine greatly limits the use of radiation for patients with intra-abdominal tumor diseases including women with ovarian cancer. Here we sought to investigate the safety and efficacy of FLASH radiation therapy in the treatment of widespread ovarian cancer peritoneal metastases. We performed abdominal irradiation on healthy and ovarian tumor-bearing mice at conventional (CONV, (0.07 Gy/sec)) or FLASH (200 Gy/sec) dose rates and examined gut function by stool counts, DNA damage in crypt cells by γ-H2AX staining, cell death and proliferation by TUNEL/ caspase-3 staining and BrdU immunohistochemistry respectively. We report that ultrahigh dose rate FLASH irradiation causes significantly less radiation-induced intestinal injury in both healthy and tumor-bearing mice compared to CONV dose rate irradiation. Abdominal FLASH reduced the mortality from gastrointestinal syndrome, preserved gut function and epithelial integrity as reflected by their stool counts and FITC-Dextran analysis. In addition, we found decreased cell death and enhanced proliferation of crypt base columnar cells (CBCs) following FLASH irradiation in comparison to CONV irradiation. We also detected reduced number of γ-H2AX foci in crypt cells indicating less DNA damage and/or increased DNA repair after FLASH compared to CONV irradiation. Importantly, FLASH and CONV irradiation have similar efficacy in the reduction of ovarian cancer peritoneal metastases. These findings suggest that FLASH irradiation has biological advantages compared to conventional dose rate irradiation in reducing radiation-induced intestinal injury within the irradiation field and therefore may be an effective strategy to enhance the therapeutic index of radiotherapy for the treatment of abdominal and pelvic tumor disease.
Citation Format: Suchitra Natarajan, Karen Levy, Jinghui Wang, Stephanie Chow, Joshua Eggold, Phoebe Loo, Rakesh Manjappa, Frederick M. Lartey, Emil Schüler, Lawrie Skinner, Marjan Rafat, Ryan Ko, Anna Kim, Duaa Al Rawi, Rie von Eyben, Oliver Dorigo, Kerriann M. Casey, Edward E. Graves, Karl Bush, Amy S. Yu, Albert C. Koong, Peter G. Maxim, Billy W. Loo, Erinn B. Rankin. FLASH irradiation enhances the therapeutic index of abdominal radiotherapy in mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5351.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Marjan Rafat
- 2Department of Vanderbilt University School of Engineering, Nashville, TN
| | - Ryan Ko
- 1Stanford University, Stanford, CA
| | - Anna Kim
- 1Stanford University, Stanford, CA
| | | | | | | | | | | | | | | | | | - Peter G. Maxim
- 4Indiana University School of Medicine, Indianapolis, IN
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28
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Griffin RJ, Ahmed MM, Amendola B, Belyakov O, Bentzen SM, Butterworth KT, Chang S, Coleman CN, Djonov V, Formenti SC, Glatstein E, Guha C, Kalnicki S, Le QT, Loo BW, Mahadevan A, Massaccesi M, Maxim PG, Mohiuddin M, Mohiuddin M, Mayr NA, Obcemea C, Petersson K, Regine W, Roach M, Romanelli P, Simone CB, Snider JW, Spitz DR, Vikram B, Vozenin MC, Abdel-Wahab M, Welsh J, Wu X, Limoli CL. Understanding High-Dose, Ultra-High Dose Rate, and Spatially Fractionated Radiation Therapy. Int J Radiat Oncol Biol Phys 2020; 107:766-778. [PMID: 32298811 DOI: 10.1016/j.ijrobp.2020.03.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/12/2022]
Abstract
The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biological underpinning of these emerging techniques and the technical/physical parameters that must be further defined to drive clinical practice through innovative biologically based clinical trials.
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Affiliation(s)
- Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Mansoor M Ahmed
- Division of Cancer Treatment and Diagnosis, Rockville, Maryland
| | | | - Oleg Belyakov
- International Atomic Energy Agency, Vienna International Centre, Vienna, Austria
| | - Søren M Bentzen
- Division of Biostatistics and Bioinformatics, University of Maryland, Baltimore, Maryland
| | - Karl T Butterworth
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, United Kingdom
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | | | - Valentin Djonov
- Bern Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Sylvia C Formenti
- Department of Radiation Oncology, Weill Cornell Medicine, New York, New York
| | - Eli Glatstein
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Chandan Guha
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York
| | - Shalom Kalnicki
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University Medical Center, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University Medical Center, Stanford, California
| | - Anand Mahadevan
- Department of Radiation Oncology, Geisinger Health Systems, Danville, Pennsylvania
| | - Mariangela Massaccesi
- Department of Radiation Oncology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | | | | | - Nina A Mayr
- Department of Radiation Oncology, University of Washington Medical Center, Seattle, Washington
| | | | - Kristoffer Petersson
- Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - William Regine
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mack Roach
- Department of Radiation Oncology & Urology, University of California, San Francisco, San Francisco, California
| | | | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, New York
| | - James W Snider
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Douglas R Spitz
- Free Radical & Radiation Biology Program, University of Iowa, Iowa City, Iowa
| | | | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital, Switzerland
| | - May Abdel-Wahab
- International Atomic Energy Agency Headquarters, Vienna International Centre, Vienna, Austria
| | - James Welsh
- Edward Hines VA Medical Center and Loyola University Stritch School of Medicine, Chicago, Illinois
| | - Xiaodong Wu
- Executive Medical Physics Associates, Miami, Florida; Shanghai Proton and Heavy Ion Center, Shanghai, China
| | - Charles L Limoli
- Department of Radiation Oncology, University of California-Irvine, Irvine, California.
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29
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Binkley MS, Koenig JL, Kashyap M, Xiang M, Liu Y, Sodji Q, Maxim PG, Diehn M, Loo BW, Gensheimer MF. Predicting per-lesion local recurrence in locally advanced non-small cell lung cancer following definitive radiation therapy using pre- and mid-treatment metabolic tumor volume. Radiat Oncol 2020; 15:114. [PMID: 32429982 PMCID: PMC7238662 DOI: 10.1186/s13014-020-01546-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We evaluated whether pre- and mid-treatment metabolic tumor volume (MTV) predicts per lesion local recurrence (LR) in patients treated with definitive radiation therapy (RT, dose≥60 Gy) for locally advanced non-small cell lung cancer (NSCLC). METHODS We retrospectively reviewed records of patients with stage III NSCLC treated from 2006 to 2018 with pre- and mid-RT PET-CT. We measured the MTV of treated lesions on the pre-RT (MTVpre) and mid-RT (MTVmid) PET-CT. LR was defined per lesion as recurrence within the planning target volume. Receiver operating characteristic (ROC) curves, cumulative incidence rates, and uni- and multivariable (MVA) competing risk regressions were used to evaluate the association between MTV and LR. RESULTS We identified 111 patients with 387 lesions (112 lung tumors and 275 lymph nodes). Median age was 68 years, 69.4% were male, 46.8% had adenocarcinoma, 39.6% had squamous cell carcinoma, and 95.5% received concurrent chemotherapy. Median follow-up was 38.7 months. 3-year overall survival was 42.3%. 3-year cumulative incidence of LR was 26.8% per patient and 11.9% per lesion. Both MTVpre and MTVmid were predictive of LR by ROC (AUC = 0.71 and 0.76, respectively) and were significantly associated with LR on MVA (P = 0.004 and P = 7.1e-5, respectively). Among lesions at lower risk of LR based on MTVpre, higher MTVmid was associated with LR (P = 0.001). CONCLUSION Per-lesion, larger MTVpre and MTVmid predicted for increased risk of LR. MTVmid was more highly predictive of LR than MTVpre and if validated may allow for further discrimination of high-risk lesions at mid-RT informing dose painting strategies.
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Affiliation(s)
- Michael S Binkley
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Julie L Koenig
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Mehr Kashyap
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Michael Xiang
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Yufei Liu
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Quaovi Sodji
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA. .,Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Stanford, California, USA.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA.
| | - Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, 875 Blake Wilbur Dr MC 5847, Stanford, CA, 94305, USA.
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McClelland S, Overton KW, Overshiner B, Bush K, Loo BW, Skinner LB, Watson GA, Holmes JA, Hiniker SM, Maxim PG. Cost Analysis of Audiovisual-Assisted Therapeutic Ambiance in Radiation Therapy (AVATAR)-Aided Omission of Anesthesia in Radiation for Pediatric Malignancies. Pract Radiat Oncol 2019; 10:e91-e94. [PMID: 31574319 DOI: 10.1016/j.prro.2019.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/29/2019] [Accepted: 09/06/2019] [Indexed: 01/16/2023]
Abstract
PURPOSE Because children cannot reliably remain immobile during radiation therapy (RT) for cancer anatomy targeting requiring millimeter precision, daily anesthesia plays a large role in each RT session. Unfortunately, anesthesia is a source of financial burden for patients' families and is invasive and traumatic. This study attempts to assess the cost-savings benefit of audiovisual-assisted therapeutic ambiance in radiation therapy (AVATAR)-aided omission of pediatric anesthesia in RT. METHODS AND MATERIALS The baseline time of anesthesia during RT was derived from documented anesthesia billing time during RT simulation at our institution and from the published literature. Current Procedural Terminology and relative value unit codes encompassing anesthesia-related charges from radiation oncology and anesthesia were analyzed in concert with this value to calculate the total cost of pediatric anesthesia per RT session. RESULTS The mean number of RT fractions administered per patient with AVATAR-directed anesthesia omission at our institution was 19.0, similar to the 17.6 previously reported. At a mean anesthesia time exceeding 30 minutes (with mean RT duration of 4 weeks), the cost of pediatric anesthesia per RT fraction in non-AVATAR sessions was $1,904.35, yielding a total RT treatment anesthesia cost of $38,087.00 per patient (including simulation). Patients at our institution were not billed for AVATAR-assisted RT. CONCLUSIONS The ability of AVATAR to obviate the need for daily anesthesia in pediatric RT provides substantial cost-savings. These findings argue for increased utilization of AVATAR and for analyses of RT targeting the accuracy of AVATAR versus conventional anesthesia-guided treatment of pediatric malignancies.
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Affiliation(s)
- Shearwood McClelland
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana.
| | - Kent W Overton
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Brian Overshiner
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Lawrie B Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Gordon A Watson
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jordan A Holmes
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Susan M Hiniker
- Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
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Simmons DA, Lartey FM, Schüler E, Rafat M, King G, Kim A, Ko R, Semaan S, Gonzalez S, Jenkins M, Pradhan P, Shih Z, Wang J, von Eyben R, Graves EE, Maxim PG, Longo FM, Loo BW. Reduced cognitive deficits after FLASH irradiation of whole mouse brain are associated with less hippocampal dendritic spine loss and neuroinflammation. Radiother Oncol 2019; 139:4-10. [DOI: 10.1016/j.radonc.2019.06.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 05/28/2019] [Accepted: 06/07/2019] [Indexed: 01/21/2023]
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Maxim PG, Keall P, Cai J. FLASH radiotherapy: Newsflash or flash in the pan? Med Phys 2019; 46:4287-4290. [DOI: 10.1002/mp.13685] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 06/22/2019] [Indexed: 12/23/2022] Open
Affiliation(s)
- Peter G. Maxim
- Department of Radiation Oncology Indiana University School of Medicine Indianapolis IN 46202USA
| | - Paul Keall
- ACRF Image X Institute University of Sydney Camperdown NSW 2006Australia
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Moding EJ, Liang R, Lartey FM, Maxim PG, Sung A, Diehn M, Loo BW, Gensheimer MF. Predictors of Respiratory Decline Following Stereotactic Ablative Radiotherapy to Multiple Lung Tumors. Clin Lung Cancer 2019; 20:461-468.e2. [PMID: 31377143 DOI: 10.1016/j.cllc.2019.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 05/08/2019] [Accepted: 05/29/2019] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Stereotactic ablative radiotherapy (SABR) is highly effective at controlling early stage primary lung cancer and lung metastases. Although previous studies have suggested that treating multiple lung tumors with SABR is safe, post-treatment changes in respiratory function have not been analyzed in detail. PATIENTS AND METHODS We retrospectively identified patients with 2 or more primary lung cancers or lung metastases treated with SABR and analyzed clinical outcomes and predictors of toxicity. We defined a composite respiratory decline endpoint to include increased oxygen requirement, increased dyspnea scale, or death from respiratory failure not owing to disease progression. RESULTS A total of 86 patients treated with SABR to 203 lung tumors were analyzed. A total of 21.8% and 41.8% of patients developed composite respiratory decline at 2 and 4 years, respectively. When accounting for intrathoracic disease progression, 12.7% of patients developed composite respiratory decline at 2 years. Of the patients, 7.9% experienced grade 2 or greater radiation pneumonitis. No patient- or treatment-related factor predicted development of respiratory decline. The median overall survival was 46.9 months, and the median progression-free survival was 14.8 months. The cumulative incidence of local failure was 9.7% at 2 years. CONCLUSION Although our results confirm that SABR is an effective treatment modality for patients with multiple lung tumors, we observed a high rate of respiratory decline after treatment, which may be owing to a combination of treatment and disease effects. Future studies may help to determine ways to avoid pulmonary toxicity from SABR.
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Affiliation(s)
- Everett J Moding
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Rachel Liang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Frederick M Lartey
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Arthur Sung
- Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA.
| | - Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA.
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Maxim PG, Tantawi SG, Loo BW. PHASER: A platform for clinical translation of FLASH cancer radiotherapy. Radiother Oncol 2019; 139:28-33. [PMID: 31178058 DOI: 10.1016/j.radonc.2019.05.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 01/19/2023]
Abstract
Pluridirectional high-energy agile scanning electronic radiotherapy (PHASER) is next-generation medical linac technology for ultra-rapid highly conformal image-guided radiation, fast enough to "freeze" physiological motion, affording improved accuracy, precision, and potentially superior FLASH radiobiological therapeutic index. Designed for compactness, economy, and clinical efficiency, it is also intended to address barriers to global access to curative radiotherapy.
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Affiliation(s)
- Peter G Maxim
- Department of Radiation Oncology, Indiana University School of Medicine, United States.
| | - Sami G Tantawi
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, United States.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, United States; Stanford Cancer Institute, Stanford University School of Medicine, United States.
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Hiniker SM, Sodji Q, Quon A, Gutkin PM, Arksey N, Graves EE, Chin FT, Maxim PG, Diehn M, Loo BW. FLT-PET-CT for the Detection of Disease Recurrence After Stereotactic Ablative Radiotherapy or Hyperfractionation for Thoracic Malignancy: A Prospective Pilot Study. Front Oncol 2019; 9:467. [PMID: 31214507 PMCID: PMC6555304 DOI: 10.3389/fonc.2019.00467] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/15/2019] [Indexed: 02/01/2023] Open
Abstract
Differentiating local recurrence from post-treatment changes on PET scans following stereotactic ablative radiotherapy (SABR) or hyperfractionation for lung tumors is challenging. We performed a prospective pilot study of 3-deoxy-3-[18F]-fluorothymidine (FLT)-PET-CT in patients with equivocal post-radiation FDG-PET-CT to assess disease recurrence. Methods: We prospectively enrolled 10 patients, 9 treated with SABR and 1 with hyperfractionated external beam radiotherapy for thoracic malignancy with subsequent equivocal follow-up FDG-PET-CT, to undergo FLT-PET-CT prior to biopsy or serial imaging. FLT-PET scans were interpreted by a radiologist with experience in reading FLT-PET-CT and blinded to the results of any subsequent biopsy or imaging. Results: Of the 10 patients enrolled, 8 were evaluable after FLT-PET-CT. Based on the FLT-PET-CT, a blinded radiologist accurately predicted disease recurrence vs. inflammatory changes in 7 patients (87.5%). The combination of higher lesion SUVmax and higher ratio of lesion SUVmax to SUVmax of mediastinal blood pool was indicative of recurrence. Qualitative assessment of increased degree of focality of the lesion also appears to be indicative of disease recurrence. Conclusion: Adjunctive FLT-PET-CT imaging can complement FDG-PET-CT scan in distinguishing post-treatment radiation changes from disease recurrence in thoracic malignancies. These findings support the investigation of FLT-PET-CT in a larger prospective study.
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Affiliation(s)
- Susan M Hiniker
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Quaovi Sodji
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Andrew Quon
- Department of Nuclear Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Paulina M Gutkin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States
| | - Natasha Arksey
- Department of Nuclear Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States
| | - Frederick T Chin
- Department of Nuclear Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Peter G Maxim
- Department of Radiation Oncology, Indiana University, Indianapolis, IN, United States
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, United States
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Prionas ND, von Eyben R, Yi E, Aggarwal S, Shaffer J, Bazan J, Eastham D, Maxim PG, Graves EE, Diehn M, Gensheimer MF, Loo BW. Increases in Serial Pretreatment 18F-FDG PET-CT Metrics Predict Survival in Early Stage Non-Small Cell Lung Cancer Treated With Stereotactic Ablative Radiation Therapy. Adv Radiat Oncol 2019; 4:429-437. [PMID: 31011689 PMCID: PMC6460103 DOI: 10.1016/j.adro.2018.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 11/14/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose Quantitative changes in positron emission tomography with computed tomography imaging metrics over serial scans may be predictive biomarkers. We evaluated the relationship of pretreatment metabolic tumor growth rate (MTGR) and standardized uptake value velocity (SUVV) with disease recurrence or death in patients with early-stage non-small cell lung cancer treated with stereotactic ablative radiation therapy (SABR). Methods and Materials Under institutional review board approval, we retrospectively identified patients who underwent positron emission tomography with computed tomography at diagnosis and staging and simulation for SABR. Two cohorts underwent SABR between November 2005 to October 2012 (discovery) and January 2012 to April 2016 (validation). MTGR and SUVV were calculated as the daily change in metabolic tumor volume and maximum standardized uptake value, respectively. Cox proportional hazard models identified predictors of local, regional, and distant recurrence and death for the combined cohort. MTGR and SUVV thresholds dichotomizing risk of death in the discovery cohort were applied to the validation cohort. Results A total of 152 lesions were identified in 143 patients (92 lesions in 83 discovery cohort patients). In multivariable models, increasing MTGR trended toward increased hazard of distant recurrence (hazard ratio, 6.98; 95% confidence interval, 0.67-72.61; P = .10). In univariable models, SUVV trended toward risk of death (hazard ratio, 11.8, 95% confidence interval, 0.85-165.1, P = .07). MTGR greater than 0.04 mL/d was prognostic of decreased survival in discovery (P = .048) and validation cohorts (P < .01). Conclusions MTGR greater than 0.04 mL/d is prognostic of death in patients with non-small cell lung cancer treated with SABR. Increasing SUVV trends, nonsignificantly, toward increased risk of recurrence and death. MTGR and SUVV may be candidate imaging biomarkers to study in trials evaluating systemic therapy with SABR for patients at high risk of out-of-field recurrence.
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Affiliation(s)
- Nicolas D Prionas
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Esther Yi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Sonya Aggarwal
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Jenny Shaffer
- St. Anthony's Radiation Oncology Specialists, St. Anthony's Medical Center, St Louis, Missouri
| | - Jose Bazan
- Department of Radiation Oncology, The James Cancer Hospital and Solove Research Institute, Columbus, Ohio
| | - David Eastham
- David Grant Medical Center Radiation Oncology, Travis Air Force Base, Fairfield, California
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California.,Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford, California
| | - Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Stanford Cancer Institute, Stanford, California
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Pinkham DW, Negahdar M, Yamamoto T, Mittra E, Diehn M, Nair VS, Keall PJ, Maxim PG, Loo BW. A Feasibility Study of Single-inhalation, Single-energy Xenon-enhanced CT for High-resolution Imaging of Regional Lung Ventilation in Humans. Acad Radiol 2019; 26:38-49. [PMID: 29606339 DOI: 10.1016/j.acra.2018.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/01/2018] [Accepted: 03/07/2018] [Indexed: 11/30/2022]
Abstract
RATIONALE AND OBJECTIVES The objective of this study was to assess the feasibility of single-inhalation xenon-enhanced computed tomography (XeCT) to provide clinically practical, high-resolution pulmonary ventilation imaging to clinics with access to only a single-energy computed tomography scanner, and to reduce the subject's overall exposure to xenon by utilizing a higher (70%) concentration for a much shorter time than has been employed in prior studies. MATERIALS AND METHODS We conducted an institutional review board-approved prospective feasibility study of XeCT for 15 patients undergoing thoracic radiotherapy. For XeCT, we acquired two breath-hold single-energy computed tomography images of the entire lung with a single inhalation each of 100% oxygen and a mixture of 70% xenon and 30% oxygen, respectively. A video biofeedback system for coached patient breathing was used to achieve reproducible breath holds. We assessed the technical success of XeCT acquisition and side effects. We then used deformable image registration to align the breath-hold images with each other to accurately subtract them, producing a map of lung xenon distribution. Additionally, we acquired ventilation single-photon emission computed tomography-computed tomography (V-SPECT-CT) images for 11 of the 15 patients. For a comparative analysis, we partitioned each lung into 12 sectors, calculated the xenon concentration from the Hounsfield unit enhancement in each sector, and then correlated this with the corresponding V-SPECT-CT counts. RESULTS XeCT scans were tolerated well overall, with a mild (grade 1) dizziness as the only side effect in 5 of the 15 patients. Technical failures in five patients occurred because of inaccurate breathing synchronization with xenon gas delivery, leaving seven patients analyzable for XeCT and single-photon emission computed tomography correlation. Sector-wise correlations were strong (Spearman coefficient >0.75, Pearson coefficient >0.65, P value <.002) for two patients for whom ventilation deficits were visibly pronounced in both scans. Correlations were nonsignificant for the remaining five who had more homogeneous XeCT ventilation maps, as well as strong V-SPECT-CT imaging artifacts attributable to airway deposition of the aerosolized imaging agent. Qualitatively, XeCT demonstrated higher resolution and no central airway deposition artifacts compared to V-SPECT-CT. CONCLUSIONS In this pilot study, single-breath XeCT ventilation imaging was generally feasible for patients undergoing thoracic radiotherapy, using an imaging protocol that is clinically practical and potentially widely available. In the future, the xenon delivery failures can be addressed by straightforward technical improvements to the patient biofeedback coaching system.
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Affiliation(s)
- Daniel W Pinkham
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305
| | - Mohammadreza Negahdar
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305; Almaden Research Center, IBM Research, San Jose, California
| | - Tokihiro Yamamoto
- Department of Radiation Oncology, University of California, Davis, Sacramento, California
| | - Erik Mittra
- Department of Radiology, Stanford University, Stanford, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305
| | - Viswam S Nair
- Division of Pulmonary & Critical Care Medicine, Stanford University, Stanford, California
| | - Paul J Keall
- Radiation Physics Laboratory, The University of Sydney, NSW, Australia
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305.
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Starkov P, Aguilera TA, Golden DI, Shultz DB, Trakul N, Maxim PG, Le QT, Loo BW, Diehn M, Depeursinge A, Rubin DL. The use of texture-based radiomics CT analysis to predict outcomes in early-stage non-small cell lung cancer treated with stereotactic ablative radiotherapy. Br J Radiol 2018; 92:20180228. [PMID: 30457885 DOI: 10.1259/bjr.20180228] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE: Stereotactic ablative radiotherapy (SABR) is being increasingly used as a non-invasive treatment for early-stage non-small cell lung cancer (NSCLC). A non-invasive method to estimate treatment outcomes in these patients would be valuable, especially since access to tissue specimens is often difficult in these cases. METHODS: We developed a method to predict survival following SABR in NSCLC patients using analysis of quantitative image features on pre-treatment CT images. We developed a Cox Lasso model based on two-dimensional Riesz wavelet quantitative texture features on CT scans with the goal of separating patients based on survival. RESULTS: The median log-rank p-value for 1000 cross-validations was 0.030. Our model was able to separate patients based upon predicted survival. When we added tumor size into the model, the p-value lost its significance, demonstrating that tumor size is not a key feature in the model but rather decreases significance likely due to the relatively small number of events in the dataset. Furthermore, running the model using Riesz features extracted either from the solid component of the tumor or from the ground glass opacity (GGO) component of the tumor maintained statistical significance. However, the p-value improved when combining features from the solid and the GGO components, demonstrating that there are important data that can be extracted from the entire tumor. CONCLUSIONS: The model predicting patient survival following SABR in NSCLC may be useful in future studies by enabling prediction of survival-based outcomes using radiomics features in CT images. ADVANCES IN KNOWLEDGE: Quantitative image features from NSCLC nodules on CT images have been found to significantly separate patient populations based on overall survival (p = 0.04). In the long term, a non-invasive method to estimate treatment outcomes in patients undergoing SABR would be valuable, especially since access to tissue specimens is often difficult in these cases.
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Affiliation(s)
- Pierre Starkov
- 1 Deparment of Signal Processing & Control, Systems, Centre Suisse d'Electronique et de Microtechnique , Neuchâtel , Switzerland
| | - Todd A Aguilera
- 2 Department of Radiation Oncology, UT Southwestern Medical Center , Dallas, TX , USA
| | - Daniel I Golden
- 3 Department of Biomedical Data Science, Radiology, and Medicine (Biomedical Informatics Research), Stanford University School of Medicine , Stanford, CA , USA
| | - David B Shultz
- 4 Department of Radiation Oncology, Princess Margaret Cancer Centre , Toronto, ON , Canada
| | - Nicholas Trakul
- 5 Department of Radiation Oncology, Stanford Cancer Institute and Stanford University School of Medicine , Stanford, CA , USA
| | - Peter G Maxim
- 5 Department of Radiation Oncology, Stanford Cancer Institute and Stanford University School of Medicine , Stanford, CA , USA
| | - Quynh-Thu Le
- 5 Department of Radiation Oncology, Stanford Cancer Institute and Stanford University School of Medicine , Stanford, CA , USA
| | - Billy W Loo
- 5 Department of Radiation Oncology, Stanford Cancer Institute and Stanford University School of Medicine , Stanford, CA , USA
| | - Maximillan Diehn
- 5 Department of Radiation Oncology, Stanford Cancer Institute and Stanford University School of Medicine , Stanford, CA , USA
| | - Adrien Depeursinge
- 6 Department of Signal Processing & Control, Systems, Biomedical Imaging Group, École Polytechnique Fédérale de Lausanne , Lausanne , Switzerland.,7 Department of Signal Processing & Control, Systems, Institute of Information Systems, University of Applied Sciences Western Switzerland (HES-SO) , Sierre , Switzerland
| | - Daniel L Rubin
- 3 Department of Biomedical Data Science, Radiology, and Medicine (Biomedical Informatics Research), Stanford University School of Medicine , Stanford, CA , USA
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Yu AS, Maxim PG, Loo BW, Gensheimer MF. Chest wall dose reduction using noncoplanar volumetric modulated arc radiation therapy for lung stereotactic ablative radiation therapy. Pract Radiat Oncol 2017; 8:e199-e207. [PMID: 29452868 DOI: 10.1016/j.prro.2017.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/08/2017] [Accepted: 12/11/2017] [Indexed: 11/17/2022]
Abstract
PURPOSE Stereotactic ablative radiation therapy (SABR) to lung tumors close to the chest wall can cause rib fractures or chest wall pain. We evaluated and propose a clinically practical solution of using noncoplanar volumetric modulated arc radiation therapy (VMAT) to reduce chest wall dose from lung SABR. METHODS AND MATERIALS Twenty lung SABR VMAT plans in which the chest wall volume receiving 30 Gy or higher (V30) exceeded 30 mL were replanned by noncoplanar VMAT with opposite 15° couch kicks. Dosimetric parameters including chest wall V30 and V40; lung V5, V10, V20, and mean dose; Paddick high-dose conformity index; intermediate-dose conformity index; and monitor units (MU) for each plan were used to evaluate the plan quality. The treatment time was also estimated by delivering the entire treatment. Two-sided paired t test was used to evaluate the difference of the dosimetric parameters between coplanar 1 arc (cVMAT1), coplanar 2 arcs (cVMAT2), and noncoplanar two arcs (nVMAT2) plans; differences with P < .05 were considered statistically significant. RESULTS V30 and V40 for chest wall were reduced on average by 20% ± 9% and 15% ± 11% (mean ± standard deviation) from cVMAT2 plans to nVMAT2 plans (P < .01 for both comparisons) and by 8% ± 7% and 16% ± 13% from cVMAT1 plans to cVMAT2 plans (P < .003 for both comparisons). The differences in lung mean dose were <0.2 Gy among cVMAT1, cVMAT2, and nVMAT2. There were no significant differences in lung V5, V10, and V20. On average, the number of MU increased 14% for nVMAT2 compared with cVMAT2. The Paddick high-dose conformity indexes were 0.88 ± 0.03, 0.89 ± 0.04, and 0.91 ± 0.03, and intermediate-dose conformity indexes were 3.88 ± 0.49, 3.80 ± 0.44 and 3.51 ± 0.38 for cVMAT1, cVMAT2, and nVMAT2, respectively. CONCLUSIONS We found that noncoplanar VMAT plans are feasible, clinically practical to deliver, and significantly reduce V30 and V40 of chest wall without increasing lung dose.
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Affiliation(s)
- Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
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Wang J, Trovati S, Borchard PM, Loo BW, Maxim PG, Fahrig R. Thermal limits on MV x-ray production by bremsstrahlung targets in the context of novel linear accelerators. Med Phys 2017; 44:6610-6620. [PMID: 28983960 DOI: 10.1002/mp.12615] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/25/2017] [Accepted: 09/20/2017] [Indexed: 12/20/2022] Open
Abstract
PURPOSE To study the impact of target geometrical and linac operational parameters, such as target material and thickness, electron beam size, repetition rate, and mean current on the ability of the radiotherapy treatment head to deliver high-dose-rate x-ray irradiation in the context of novel linear accelerators capable of higher repetition rates/duty cycle than conventional clinical linacs. METHODS The depth dose in a water phantom without a flattening filter and heat deposition in an x-ray target by 10 MeV pulsed electron beams were calculated using the Monte-Carlo code MCNPX, and the transient temperature behavior of the target was simulated by ANSYS. Several parameters that affect both the dose distribution and temperature behavior were investigated. The target was tungsten with a thickness ranging from 0 to 3 mm and a copper heat remover layer. An electron beam with full width at half maximum (FWHM) between 0 and3 mm and mean current of 0.05-2 mA was used as the primary beam at repetition rates of 100, 200, 400, and 800 Hz. RESULTS For a 10 MeV electron beam with FWHM of 1 mm, pulse length of 5 μs, by using a thin tungsten target with thickness of 0.2 mm instead of 1 mm, and by employing a high repetition rate of 800 Hz instead of 100 Hz, the maximum dose rate delivered can increase two times from 0.57 to 1.16 Gy/s. In this simple model, the limiting factor on dose rate is the copper heat remover's softening temperature, which was considered to be 500°C in our study. CONCLUSIONS A high dose rate can be obtained by employing thin targets together with high repetition rate electron beams enabled by novel linac designs, whereas the benefit of thin targets is marginal at conventional repetition rates. Next generation linacs used to increase dose rate need different target designs compared to conventional linacs.
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Affiliation(s)
- Jinghui Wang
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA.,Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Stefania Trovati
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | | | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Rebecca Fahrig
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA.,Siemens Healthcare GmbH, Erlangen, 91052, Germany
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42
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Hiniker SM, Bush K, Fowler T, White EC, Rodriguez S, Maxim PG, Donaldson SS, Loo BW. Initial clinical outcomes of audiovisual-assisted therapeutic ambience in radiation therapy (AVATAR). Pract Radiat Oncol 2017; 7:311-318. [DOI: 10.1016/j.prro.2017.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/14/2016] [Accepted: 01/16/2017] [Indexed: 12/26/2022]
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43
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Gensheimer MF, Hong JC, Chang-Halpenny C, Zhu H, Eclov NCW, To J, Murphy JD, Wakelee HA, Neal JW, Le QT, Hara WY, Quon A, Maxim PG, Graves EE, Olson MR, Diehn M, Loo BW. Mid-radiotherapy PET/CT for prognostication and detection of early progression in patients with stage III non-small cell lung cancer. Radiother Oncol 2017; 125:338-343. [PMID: 28830717 DOI: 10.1016/j.radonc.2017.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 05/22/2017] [Accepted: 08/05/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE Pre- and mid-radiotherapy FDG-PET metrics have been proposed as biomarkers of recurrence and survival in patients treated for stage III non-small cell lung cancer. We evaluated these metrics in patients treated with definitive radiation therapy (RT). We also evaluated outcomes after progression on mid-radiotherapy PET/CT. MATERIAL AND METHODS Seventy-seven patients treated with RT with or without chemotherapy were included in this retrospective study. Primary tumor and involved nodes were delineated. PET metrics included metabolic tumor volume (MTV), total lesion glycolysis (TLG), and SUVmax. For mid-radiotherapy PET, both absolute value of these metrics and percentage decrease were analyzed. The influence of PET metrics on time to death, local recurrence, and regional/distant recurrence was assessed using Cox regression. RESULTS 91% of patients had concurrent chemotherapy. Median follow-up was 14months. None of the PET metrics were associated with overall survival. Several were positively associated with local recurrence: pre-radiotherapy MTV, and mid-radiotherapy MTV and TLG (p=0.03-0.05). Ratio of mid- to pre-treatment SUVmax was associated with regional/distant recurrence (p=0.02). 5/77 mid-radiotherapy scans showed early out-of-field progression. All of these patients died. CONCLUSIONS Several PET metrics were associated with risk of recurrence. Progression on mid-radiotherapy PET/CT was a poor prognostic factor.
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Affiliation(s)
- Michael F Gensheimer
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA.
| | - Julian C Hong
- Department of Radiation Oncology, Stanford University, USA; Department of Radiation Oncology, Duke University, Durham, USA
| | - Christine Chang-Halpenny
- Department of Radiation Oncology, Stanford University, USA; Department of Radiation Oncology, cCARE, Fresno, USA
| | - Hui Zhu
- Department of Radiation Oncology, Stanford University, USA; Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Jinan, China
| | - Neville C W Eclov
- Department of Radiation Oncology, Stanford University, USA; University of Chicago, USA
| | - Jacqueline To
- Department of Radiation Oncology, Stanford University, USA; University of Colorado, USA
| | - James D Murphy
- Department of Radiation Oncology, Stanford University, USA; Department of Radiation Medicine and Applied Sciences, University of California San Diego, USA
| | - Heather A Wakelee
- Stanford Cancer Institute, Stanford University School of Medicine, USA; Department of Medicine, Division of Oncology, Stanford University, USA
| | - Joel W Neal
- Stanford Cancer Institute, Stanford University School of Medicine, USA; Department of Medicine, Division of Oncology, Stanford University, USA
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA
| | - Wendy Y Hara
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA
| | - Andrew Quon
- Department of Nuclear Medicine, University of California Los Angeles, USA
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA
| | - Michael R Olson
- Department of Radiation Oncology, Stanford University, USA; Florida Radiation Oncology Group, Baptist Medical Center, Jacksonville, USA
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, USA.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, USA; Stanford Cancer Institute, Stanford University School of Medicine, USA.
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44
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Gensheimer MF, Bush K, Juang T, Herzberg B, Villegas M, Maxim PG, Diehn M, Loo BW. Practical workflow for rapid prototyping of radiation therapy positioning devices. Pract Radiat Oncol 2017; 7:442-445. [PMID: 28668669 DOI: 10.1016/j.prro.2017.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 11/16/2022]
Affiliation(s)
- Michael F Gensheimer
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - Titania Juang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Bob Herzberg
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Manuel Villegas
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California; Institute for Stem Cell Biology and Regenerative Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
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Loo BW, Schuler E, Lartey FM, Rafat M, King GJ, Trovati S, Koong AC, Maxim PG. (P003) Delivery of Ultra-Rapid Flash Radiation Therapy and Demonstration of Normal Tissue Sparing After Abdominal Irradiation of Mice. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.02.101] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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46
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Schüler E, Eriksson K, Hynning E, Hancock SL, Hiniker SM, Bazalova‐Carter M, Wong T, Le Q, Loo BW, Maxim PG. Very high‐energy electron (
VHEE
) beams in radiation therapy; Treatment plan comparison between
VHEE
,
VMAT
, and
PPBS. Med Phys 2017; 44:2544-2555. [DOI: 10.1002/mp.12233] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 11/11/2022] Open
Affiliation(s)
- Emil Schüler
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
| | | | | | - Steven L. Hancock
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
| | - Susan M. Hiniker
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
| | | | - Tony Wong
- Seattle Cancer Care Alliance Proton Therapy Center Seattle WA USA
| | - Quynh‐Thu Le
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
| | - Billy W. Loo
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
| | - Peter G. Maxim
- Department of Radiation Oncology Stanford School of Medicine Stanford University Stanford CA USA
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Binkley MS, King MT, Shrager JB, Bush K, Chaudhuri AA, Popat R, Gensheimer MF, Maxim PG, Henry Guo H, Diehn M, Nair VS, Loo BW. Pulmonary function after lung tumor stereotactic ablative radiotherapy depends on regional ventilation within irradiated lung. Radiother Oncol 2017; 123:270-275. [PMID: 28460826 DOI: 10.1016/j.radonc.2017.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/07/2017] [Accepted: 03/20/2017] [Indexed: 12/17/2022]
Abstract
PURPOSE To determine if regional ventilation within irradiated lung volume predicts change in pulmonary function test (PFT) measurements after stereotactic ablative radiotherapy (SABR) of lung tumors. METHODS We retrospectively identified 27 patients treated from 2007 to 2014 at our institution who received: (1) SABR without prior thoracic radiation; (2) pre-treatment 4-dimensional computed tomography (4-D CT) imaging; (3) pre- and post-SABR PFTs <15months from treatment. We defined the ventilation ratio (VR20BED3) as the quotient of mean ventilation (mean Jacobian-based per-voxel volume change on deformably registered inhale/exhale 4-D CT phases) within the 20Gy biologically effective dose (α/β=3Gy) isodose volume and that of the total lung volume (TLV). RESULTS Most patients had moderate to very severe COPD by GOLD criteria (n=19, 70.1%). Higher VR20BED3 significantly predicted worse change in Forced Expiratory Volume/s normalized by baseline value (ΔFEV1/FEV1pre, p=0.04); n=7 had VR20BED3>1 (high regional ventilation) and worse ΔFEV1/FEV1pre (median=-0.16, range=-0.230 to -0.20). Five had VR20BED3<1 (low regional ventilation) and improved ΔFEV1/FEV1pre (median=0.13, range=0.07 to 0.20). In a multivariable linear model, increasing VR20BED3 and time to post-SABR PFT predicted decreasing ΔFEV1/FEV1pre (R2=0.25, p=0.03). CONCLUSIONS After SABR to high versus low functioning lung regions, we found worsened or improved global pulmonary function, respectively. If pre-SABR VR20BED3 is validated as a predictor of eventual post-SABR PFT in larger studies, it may be used for individualized treatment planning to preserve or even improve pulmonary function after SABR.
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Affiliation(s)
- Michael S Binkley
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States
| | - Martin T King
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States
| | - Joseph B Shrager
- Department of Cardiothoracic Surgery, Division of Thoracic Surgery, Stanford University School of Medicine, United States; Stanford Cancer Institute and Department of Medicine, United States
| | - Karl Bush
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States
| | - Aadel A Chaudhuri
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States
| | - Rita Popat
- Department of Health Research & Policy, Stanford University School of Medicine, United States
| | - Michael F Gensheimer
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States
| | - Peter G Maxim
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States; Stanford Cancer Institute and Department of Medicine, United States
| | - H Henry Guo
- Department of Radiology, Stanford University School of Medicine, United States
| | - Maximilian Diehn
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States; Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, United States; Stanford Cancer Institute and Department of Medicine, United States
| | - Viswam S Nair
- Department of Radiology, Stanford University School of Medicine, United States; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Stanford Cancer Institute and Department of Medicine, United States; Stanford Cancer Institute and Department of Medicine, United States.
| | - Billy W Loo
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, United States; Stanford Cancer Institute and Department of Medicine, United States.
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Schüler E, Trovati S, King G, Lartey F, Rafat M, Villegas M, Praxel AJ, Loo BW, Maxim PG. Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator. Int J Radiat Oncol Biol Phys 2017; 97:195-203. [DOI: 10.1016/j.ijrobp.2016.09.018] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/15/2016] [Accepted: 09/14/2016] [Indexed: 11/24/2022]
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49
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Cherry Kemmerling EM, Wu M, Yang H, Maxim PG, Loo BW, Fahrig R. Optimization of an on-board imaging system for extremely rapid radiation therapy. Med Phys 2016; 42:6757-67. [PMID: 26520765 DOI: 10.1118/1.4934377] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. METHODS Three different CT detectors are proposed: low-resolution (all 4×4 mm pixels), medium-resolution (a combination of 4×4 mm pixels and 2×2 mm pixels), and high-resolution (all 1×1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called "realistic" images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a "gold standard" deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields--the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration deformation fields was computed. RESULTS By most global metrics (e.g., mean, median, and maximum pointwise distance), the high-resolution detector had the best performance but the medium-resolution detector was comparable. For all medium- and high-resolution detector registrations, mean error between the realistic and gold standard deformation fields was less than 4 mm. By pointwise metrics (e.g., tracking a small lesion), the high- and medium-resolution detectors performed similarly. For these detectors, the smallest error between the realistic and gold standard registrations was 0.6 mm and the largest error was 3.6 mm. CONCLUSIONS The medium-resolution CT detector was selected as the best for an extremely rapid radiation therapy system. In essentially all test cases, data from this detector produced a significantly better registration than data from the low-resolution detector and a comparable registration to data from the high-resolution detector. The medium-resolution detector provides an appropriate compromise between registration accuracy and system cost.
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Affiliation(s)
| | - Meng Wu
- Department of Radiology, Stanford University, Stanford, California 94305
| | - He Yang
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University, Stanford, California 94305 and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, Stanford, California 94305 and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Rebecca Fahrig
- Department of Radiology, Stanford University, Stanford, California 94305
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50
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Dong X, Sun X, Sun L, Maxim PG, Xing L, Huang Y, Li W, Wan H, Zhao X, Xing L, Yu J. Early Change in Metabolic Tumor Heterogeneity during Chemoradiotherapy and Its Prognostic Value for Patients with Locally Advanced Non-Small Cell Lung Cancer. PLoS One 2016; 11:e0157836. [PMID: 27322376 PMCID: PMC4913903 DOI: 10.1371/journal.pone.0157836] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 06/06/2016] [Indexed: 12/25/2022] Open
Abstract
Introduction To observe the early change of metabolic tumor heterogeneity during chemoradiotherapy and to determine its prognostic value for patients with locally advanced non-small cell lung cancer (NSCLC). Methods From January 2007 to March 2010, 58 patients with NSCLC were included who were received 18F-fluorodeoxyglucose (18F-FDG) PET/CT before and following 40 Gy radiotherapy with the concurrent cisplatin-based chemotherapy (CCRT). Primary tumor FDG uptake heterogeneity was determined using global and local scale textural features extracted from standardized uptake value (SUV) histogram analysis (coefficient of variation [COV], skewness, kurtosis, area under the curve of the cumulative SUV histogram [AUC-CSH]) and normalized gray-level co-occurrence matrix (contrast, dissimilarity, entropy, homogeneity). SUVmax and metabolic tumor volume (MTV) were also evaluated. Correlations were analyzed between parameters on baseline or during treatments with tumor response, progression-free survival (PFS), and overall survival (OS). Results Compared with non-responders, responders showed significantly greater pre-treatment COV, contrast and MTV (AUC = 0.781, 0.804, 0.686, respectively). Receiver-operating-characteristic curve analysis showed that early change of tumor textural analysis serves as a response predictor with higher sensitivity (73.2%~92.1%) and specificity (80.0%~83.6%) than baseline parameters. Change in AUC-CSH and dissimilarity during CCRT could also predict response with optimal cut-off values (33.0% and 28.7%, respectively). The patients with greater changes in contrast and AUC-CSH had significantly higher 5-year OS (P = 0.008, P = 0.034) and PFS (P = 0.007, P = 0.039). In multivariate analysis, only change in contrast was found as the independent prognostic factor of PFS (HR 0.476, P = 0.021) and OS (HR 0.519, P = 0.015). Conclusions The metabolic tumor heterogeneity change during CCRT characterized by global and local scale textural features may be valuable for predicting treatment response and survival for patients with locally advanced NSCLC.
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Affiliation(s)
- Xinzhe Dong
- Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China
- Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
| | - Xiaorong Sun
- Department of Radiology, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
| | - Lu Sun
- Jinan University, Jinan, Shandong, China
| | - Peter G. Maxim
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Lei Xing
- Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Yong Huang
- Department of Radiology, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
| | - Wenwu Li
- Department of Radiology, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
| | - Honglin Wan
- College of Physics and Electronic Science, Shandong Normal University, Jinan, Shandong, China
| | - Xianguang Zhao
- Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China
- Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
- * E-mail: (XZ); (LX)
| | - Ligang Xing
- Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China
- Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
- * E-mail: (XZ); (LX)
| | - Jinming Yu
- Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China
- Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
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