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Sheikh K, Li H, Wright JL, Yanagihara TK, Halthore A. The Peaks and Valleys of Photon Versus Proton Spatially Fractionated Radiotherapy. Semin Radiat Oncol 2024; 34:292-301. [PMID: 38880538 DOI: 10.1016/j.semradonc.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Spatially-fractionated radiotherapy (SFRT) delivers high doses to small areas of tumor while sparing adjacent tissue, including intervening disease. In this review, we explore the evolution of SFRT technological advances, contrasting approaches with photon and proton beam radiotherapy. We discuss unique dosimetric considerations and physical properties of SFRT, as well as review the preclinical literature that provides an emerging understanding of biological mechanisms. We emphasize crucial areas of future study and highlight clinical trials that are underway to assess SFRT's safety and efficacy, with a focus on immunotherapeutic synergies. The review concludes with practical considerations for SFRT's clinical application, advocating for strategies that leverage its unique dosimetric and biological properties for improved patient outcomes.
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Affiliation(s)
- Khadija Sheikh
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC.
| | - Heng Li
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC
| | - Jean L Wright
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC
| | - Theodore K Yanagihara
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC
| | - Aditya Halthore
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC
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2
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Li H, Mayr NA, Griffin RJ, Zhang H, Pokhrel D, Grams M, Penagaricano J, Chang S, Spraker MB, Kavanaugh J, Lin L, Sheikh K, Mossahebi S, Simone CB, Roberge D, Snider JW, Sabouri P, Molineu A, Xiao Y, Benedict SH. Overview and Recommendations for Prospective Multi-institutional Spatially Fractionated Radiation Therapy Clinical Trials. Int J Radiat Oncol Biol Phys 2024; 119:737-749. [PMID: 38110104 PMCID: PMC11162930 DOI: 10.1016/j.ijrobp.2023.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/30/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023]
Abstract
PURPOSE The highly heterogeneous dose delivery of spatially fractionated radiation therapy (SFRT) is a profound departure from standard radiation planning and reporting approaches. Early SFRT studies have shown excellent clinical outcomes. However, prospective multi-institutional clinical trials of SFRT are still lacking. This NRG Oncology/American Association of Physicists in Medicine working group consensus aimed to develop recommendations on dosimetric planning, delivery, and SFRT dose reporting to address this current obstacle toward the design of SFRT clinical trials. METHODS AND MATERIALS Working groups consisting of radiation oncologists, radiobiologists, and medical physicists with expertise in SFRT were formed in NRG Oncology and the American Association of Physicists in Medicine to investigate the needs and barriers in SFRT clinical trials. RESULTS Upon reviewing the SFRT technologies and methods, this group identified challenges in several areas, including the availability of SFRT, the lack of treatment planning system support for SFRT, the lack of guidance in the physics and dosimetry of SFRT, the approximated radiobiological modeling of SFRT, and the prescription and combination of SFRT with conventional radiation therapy. CONCLUSIONS Recognizing these challenges, the group further recommended several areas of improvement for the application of SFRT in cancer treatment, including the creation of clinical practice guidance documents, the improvement of treatment planning system support, the generation of treatment planning and dosimetric index reporting templates, and the development of better radiobiological models through preclinical studies and through conducting multi-institution clinical trials.
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Affiliation(s)
- Heng Li
- Department of Radiation Oncology, John Hopkins University, Baltimore, Maryland.
| | - Nina A Mayr
- College of Human Medicine, Michigan State University, East Lansing, Michigan
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Hualin Zhang
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Damodar Pokhrel
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky
| | - Michael Grams
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Jose Penagaricano
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina
| | | | - James Kavanaugh
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Liyong Lin
- Department of Radiation Oncology, Emory University, Atlanta, Georgia
| | - Khadija Sheikh
- Department of Radiation Oncology, John Hopkins University, Baltimore, Maryland
| | - Sina Mossahebi
- Department of Radiation Oncology, University of Maryland, Baltimore, Maryland
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, New York
| | - David Roberge
- Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - James W Snider
- South Florida Proton Therapy Institute, 5280 Linton Blvd, Delray Beach, Florida
| | - Pouya Sabouri
- Department of Radiation Oncology, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Andrea Molineu
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California, Davis, Sacramento, California
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Mossahebi S, Molitoris JK, Poirier Y, Jatczak J, Zhang B, Mohindra P, Ferris M, Regine WF, Yi B. Clinical Implementation and Dosimetric Evaluation of a Robust Proton Lattice Planning Strategy Using Primary and Robust Complementary Beams. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00742-9. [PMID: 38936634 DOI: 10.1016/j.ijrobp.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 05/17/2024] [Accepted: 06/15/2024] [Indexed: 06/29/2024]
Abstract
PURPOSE Pencil-beam scanning proton therapy has been considered as a potential modality for the 3D form of spatially-fractionated-radiation-therapy called lattice therapy. However, few practical solutions have been introduced in the clinic. Existing limitations include degradation in plan quality and robustness when using single-field versus multifield lattice plans, respectively. We propose a practical and robust proton lattice (RPL) planning method using multifield and evaluate its dosimetric characteristics compared to clinically acceptable photon lattice plans. METHODS Seven cases previously treated with photon lattice therapy were used to evaluate a novel RPL planning technique using two-orthogonal beams: a primary beam (PB) and a robust complementary beam (RCB) that deliver 67% and 33%, respectively, of the prescribed dose to vertices inside the gross-target-volume (GTV). Only RCB is robustly optimized for setup and range uncertainties. The number and volume of vertices, peak-to-valley dose ratios (PVDRs), and volume of low dose to GTV of proton and photon plans were compared. The RPL technique was then used in treatment of two patients and their dosimetric parameters are reported. RESULTS The RPL strategy was able to achieve the clinical planning goals. Compared to previously-treated photon plans, the average number of vertices increased by 30%, average vertex volume by 49% (18.2±25.9cc vs. 12.2±14.5cc, P=0.21), and higher PVDR (10.5±4.8 vs. 2.5±0.9, P<0.005) was achieved. In addition, RPL plans show more conformal dose with less low-dose to GTV (V30%: 60.9±7.2% vs. 81.6±13.9% and V10%: 88.3±4.5% vs. 98.6±3.6% [P<0.01]). The RPL plan for two treated patients showed PVDRs of 4.61 and 14.85 with vertices-to-GTV ratios of 1.52% and 1.30%, respectively. CONCLUSION A novel RPL planning strategy using a pair of orthogonal beams was developed and successfully translated to the clinic. The proposed method can generate better quality plans, a higher number of vertices, and higher PVDRs than currently used photon lattice plans.
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Affiliation(s)
- Sina Mossahebi
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center.
| | - Jason K Molitoris
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center
| | - Yannick Poirier
- Department of Radiation Oncology, University of Maryland School of Medicine
| | | | - Baoshe Zhang
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center
| | | | - Matthew Ferris
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center
| | - William F Regine
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center
| | - ByongYong Yi
- Department of Radiation Oncology, University of Maryland School of Medicine; Maryland Proton Treatment Center
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4
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Das IJ, Khan AU, Dogan SK, Longo M. Grid/lattice therapy: consideration of small field dosimetry. Br J Radiol 2024; 97:1088-1098. [PMID: 38552328 PMCID: PMC11135801 DOI: 10.1093/bjr/tqae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 05/31/2024] Open
Abstract
Small-field dosimetry used in special procedures such as gamma knife, Cyberknife, Tomotherapy, IMRT, and VMAT has been in evolution after several radiation incidences with very significant (70%) errors due to poor understanding of the dosimetry. IAEA-TRS-483 and AAPM-TG-155 have provided comprehensive information on small-fields dosimetry in terms of code of practice and relative dosimetry. Data for various detectors and conditions have been elaborated. It turns out that with a suitable detectors dose measurement accuracy can be reasonably (±3%) achieved for 6 MV beams for fields >1×1 cm2. For grid therapy, even though the treatment is performed with small fields created by either customized blocks, multileaf collimator (MLC), or specialized devices, it is multiple small fields that creates combined treatment. Hence understanding the dosimetry in collection of holes of small field is a separate challenge that needs to be addressed. It is more critical to understand the scattering conditions from multiple holes that form the treatment grid fields. Scattering changes the beam energy (softer) and hence dosimetry protocol needs to be properly examined for having suitable dosimetric parameters. In lieu of beam parameter unavailability in physical grid devices, MLC-based forward and inverse planning is an alternative path for bulky tumours. Selection of detectors in small field measurement is critical and it is more critical in mixed beams created by scattering condition. Ramification of small field concept used in grid therapy along with major consideration of scattering condition is explored. Even though this review article is focussed mainly for dosimetry for low-energy megavoltage photon beam (6 MV) but similar procedures could be adopted for high energy beams. To eliminate small field issues, lattice therapy with the help of MLC is a preferrable choice.
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Affiliation(s)
- Indra J Das
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Ahtesham Ullah Khan
- San Bortolo Hospital, Medical Physics Department, Viale F. Rodolfi 37, 36100 Vicenza, Italy
| | - Serpil K Dogan
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Mariaconcetta Longo
- San Bortolo Hospital, Medical Physics Department, Viale F. Rodolfi 37, 36100 Vicenza, Italy
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Prezado Y, Grams M, Jouglar E, Martínez-Rovira I, Ortiz R, Seco J, Chang S. Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps. Phys Med Biol 2024; 69:10TR02. [PMID: 38648789 DOI: 10.1088/1361-6560/ad4192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Spatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a deeper understanding of the underlying biology and its relationship with the complex dosimetry of SFRT is needed. This review provides a critical analysis of the field, discussing not only the main clinical and preclinical findings but also analyzing the main knowledge gaps in a holistic way.
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Affiliation(s)
- Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- New Approaches in Radiotherapy Lab, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Instituto de investigación Sanitaria de Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, E-15706, Spain
- Oportunius Program, Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, A Coruña, Spain
| | - Michael Grams
- Department of Radiation Oncology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, United States of America
| | - Emmanuel Jouglar
- Institut Curie, PSL Research University, Department of Radiation Oncology, F-75005, Paris and Orsay Protontherapy Center, F-91400, Orsay, France
| | - Immaculada Martínez-Rovira
- Physics Department, Universitat Auto`noma de Barcelona, E-08193, Cerdanyola del Valle`s (Barcelona), Spain
| | - Ramon Ortiz
- University of California San Francisco, Department of Radiation Oncology, 1600 Divisadero Street, San Francisco, CA 94143, United States of America
| | - Joao Seco
- Division of Biomedical physics in Radiation Oncology, DKFZ-German Cancer Research Center, Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Sha Chang
- Dept of Radiation Oncology and Department of Biomedical Engineering, University of North Carolina School of Medicine, United States of America
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolin State University, United States of America
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Reaz F, Traneus E, Bassler N. Tuning spatially fractionated radiotherapy dose profiles using the moiré effect. Sci Rep 2024; 14:8468. [PMID: 38605022 PMCID: PMC11009409 DOI: 10.1038/s41598-024-55104-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/20/2024] [Indexed: 04/13/2024] Open
Abstract
Spatially Fractionated Radiotherapy (SFRT) has demonstrated promising potential in cancer treatment, combining the advantages of reduced post-radiation effects and enhanced local control rates. Within this paradigm, proton minibeam radiotherapy (pMBRT) was suggested as a new treatment modality, possibly producing superior normal tissue sparing to conventional proton therapy, leading to improvements in patient outcomes. However, an effective and convenient beam generation method for pMBRT, capable of implementing various optimum dose profiles, is essential for its real-world application. Our study investigates the potential of utilizing the moiré effect in a dual collimator system (DCS) to generate pMBRT dose profiles with the flexibility to modify the center-to-center distance (CTC) of the dose distribution in a technically simple way.We employ the Geant4 Monte Carlo simulations tool to demonstrate that the angle between the two collimators of a DCS can significantly impact the dose profile. Varying the DCS angle from 10∘ to 50∘ we could cover CTC ranging from 11.8 mm to 2.4 mm, respectively. Further investigations reveal the substantial influence of the multi-slit collimator's (MSC) physical parameters on the spatially fractionated dose profile, such as period (CTC), throughput, and spacing between MSCs. These findings highlight opportunities for precision dose profile adjustments tailored to specific clinical scenarios.The DCS capacity for rapid angle adjustments during the energy transition stages of a spot scanning system can facilitate dynamic alterations in the irradiation profile, enhancing dose contrast in normal tissues. Furthermore, its unique attribute of spatially fractionated doses in both lateral directions could potentially improve normal tissue sparing by minimizing irradiated volume. Beyond the realm of pMBRT, the dual MSC system exhibits remarkable versatility, showing compatibility with different types of beams (X-rays and electrons) and applicability across various SFRT modalities.Our study illuminates the dual MSC system's potential as an efficient and adaptable tool in the refinement of pMBRT techniques. By enabling meticulous control over irradiation profiles, this system may expedite advancements in clinical and experimental applications, thereby contributing to the evolution of SFRT strategies.
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Affiliation(s)
- Fardous Reaz
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.
| | | | - Niels Bassler
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
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7
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Karimi AH, Das IJ, Chegeni N, Jabbari I, Jafari F, Geraily G. Beam quality and the mystery behind the lower percentage depth dose in grid radiation therapy. Sci Rep 2024; 14:4510. [PMID: 38402259 PMCID: PMC10894234 DOI: 10.1038/s41598-024-55197-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024] Open
Abstract
Grid therapy recently has been picking momentum due to favorable outcomes in bulky tumors. This is being termed as Spatially Fractionated Radiation Therapy (SFRT) and lattice therapy. SFRT can be performed with specially designed blocks made with brass or cerrobend with repeated holes or using multi-leaf collimators where dosimetry is uncertain. The dosimetric challenge in grid therapy is the mystery behind the lower percentage depth dose (PDD) in grid fields. The knowledge about the beam quality, indexed by TPR20/10 (Tissue Phantom Ratio), is also necessary for absolute dosimetry of grid fields. Since the grid may change the quality of the primary photons, a new [Formula: see text] should be evaluated for absolute dosimetry of grid fields. A Monte Carlo (MC) approach is provided to resolving the dosimetric issues. Using 6 MV beam from a linear accelerator, MC simulation was performed using MCNPX code. Additionally, a commercial grid therapy device was used to simulate the grid fields. Beam parameters were validated with MC model for output factor, depth of maximum dose, PDDs, dose profiles, and TPR20/10. The electron and photon spectra were also compared between open and grid fields. The dmax is the same for open and grid fields. The PDD with grid is lower (~ 10%) than the open field. The difference in TPR20/10 of open and grid fields is observable (~ 5%). Accordingly, TPR20/10 is still a good index for the beam quality in grid fields and consequently choose the correct [Formula: see text] in measurements. The output factors for grid fields are 0.2 lower compared to open fields. The lower depth dose with grid therapy is due to lower depth fluence with scatter radiation but it does not impact the dosimetry as the calibration parameters are insensitive to the effective beam energies. Thus, standard dosimetry in open beam based on international protocol could be used.
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Affiliation(s)
- Amir Hossein Karimi
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Radiation Oncology Department, Cancer Institute, Imam-Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Indra J Das
- Department of Radiation Oncology, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Nahid Chegeni
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Iraj Jabbari
- Department of Nuclear Engineering, Faculty of Physics, University of Isfahan, Isfahan, Iran
| | - Fatemeh Jafari
- Radiation Oncology Department, Cancer Institute, Imam-Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghazale Geraily
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Radiation Oncology Department, Cancer Institute, Imam-Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.
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8
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Clements N, Esplen N, Bateman J, Robertson C, Dosanjh M, Korysko P, Farabolini W, Corsini R, Bazalova-Carter M. Mini-GRID radiotherapy on the CLEAR very-high-energy electron beamline: collimator optimization, film dosimetry, and Monte Carlo simulations. Phys Med Biol 2024; 69:055003. [PMID: 38295408 DOI: 10.1088/1361-6560/ad247d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/31/2024] [Indexed: 02/02/2024]
Abstract
Objective.Spatially-fractionated radiotherapy (SFRT) delivered with a very-high-energy electron (VHEE) beam and a mini-GRID collimator was investigated to achieve synergistic normal tissue-sparing through spatial fractionation and the FLASH effect.Approach.A tungsten mini-GRID collimator for delivering VHEE SFRT was optimized using Monte Carlo (MC) simulations. Peak-to-valley dose ratios (PVDRs), depths of convergence (DoCs, PVDR ≤ 1.1), and peak and valley doses in a water phantom from a simulated 150 MeV VHEE source were evaluated. Collimator thickness, hole width, and septal width were varied to determine an optimal value for each parameter that maximized PVDR and DoC. The optimized collimator (20 mm thick rectangular prism with a 15 mm × 15 mm face with a 7 × 7 array of 0.5 mm holes separated by 1.1 mm septa) was 3D-printed and used for VHEE irradiations with the CERN linear electron accelerator for research beam. Open beam and mini-GRID irradiations were performed at 140, 175, and 200 MeV and dose was recorded with radiochromic films in a water tank. PVDR, central-axis (CAX) and valley dose rates and DoCs were evaluated.Main results.Films demonstrated peak and valley dose rates on the order of 100 s of MGy/s, which could promote FLASH-sparing effects. Across the three energies, PVDRs of 2-4 at 13 mm depth and DoCs between 39 and 47 mm were achieved. Open beam and mini-GRID MC simulations were run to replicate the film results at 200 MeV. For the mini-GRID irradiations, the film CAX dose was on average 15% higher, the film valley dose was 28% higher, and the film PVDR was 15% lower than calculated by MC.Significance.Ultimately, the PVDRs and DoCs were determined to be too low for a significant potential for SFRT tissue-sparing effects to be present, particularly at depth. Further beam delivery optimization and investigations of new means of spatial fractionation are warranted.
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Affiliation(s)
- Nathan Clements
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Joseph Bateman
- Department of Physics, University of Oxford, Oxford, United Kingdom
| | | | - Manjit Dosanjh
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
| | - Pierre Korysko
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
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9
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Mayr NA, Mohiuddin M, Snider JW, Zhang H, Griffin RJ, Amendola BE, Hippe DS, Perez NC, Wu X, Lo SS, Regine WF, Simone CB. Practice Patterns of Spatially Fractionated Radiation Therapy: A Clinical Practice Survey. Adv Radiat Oncol 2024; 9:101308. [PMID: 38405319 PMCID: PMC10885580 DOI: 10.1016/j.adro.2023.101308] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 06/26/2023] [Indexed: 02/27/2024] Open
Abstract
Purpose Spatially fractionated radiation therapy (SFRT) is increasingly used for bulky advanced tumors, but specifics of clinical SFRT practice remain elusive. This study aimed to determine practice patterns of GRID and Lattice radiation therapy (LRT)-based SFRT. Methods and Materials A survey was designed to identify radiation oncologists' practice patterns of patient selection for SFRT, dosing/planning, dosimetric parameter use, SFRT platforms/techniques, combinations of SFRT with conventional external beam radiation therapy (cERT) and multimodality therapies, and physicists' technical implementation, delivery, and quality procedures. Data were summarized using descriptive statistics. Group comparisons were analyzed with permutation tests. Results The majority of practicing radiation oncologists (United States, 100%; global, 72.7%) considered SFRT an accepted standard-of-care radiation therapy option for bulky/advanced tumors. Treatment of metastases/recurrences and nonmetastatic primary tumors, predominantly head and neck, lung cancer and sarcoma, was commonly practiced. In palliative SFRT, regimens of 15 to 18 Gy/1 fraction predominated (51.3%), and in curative-intent treatment of nonmetastatic tumors, 15 Gy/1 fraction (28.0%) and fractionated SFRT (24.0%) were most common. SFRT was combined with cERT commonly but not always in palliative (78.6%) and curative-intent (85.7%) treatment. SFRT-cERT time sequencing and cERT dose adjustments were variable. In curative-intent treatment, concurrent chemotherapy and immunotherapy were found acceptable by 54.5% and 28.6%, respectively. Use of SFRT dosimetric parameters was highly variable and differed between GRID and LRT. SFRT heterogeneity dosimetric parameters were more commonly used (P = .008) and more commonly thought to influence local control (peak dose, P = .008) in LRT than in GRID therapy. Conclusions SFRT has already evolved as a clinical practice pattern for advanced/bulky tumors. Major treatment approaches are consistent and follow the literature, but SFRT-cERT combination/sequencing and clinical utilization of dosimetric parameters are variable. These areas may benefit from targeted education and standardization, and knowledge gaps may be filled by incorporating identified inconsistencies into future clinical research.
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Affiliation(s)
- Nina A. Mayr
- College of Human Medicine, Michigan State University, East Lansing, Michigan
| | - Majid Mohiuddin
- Radiation Oncology Consultants and Northwestern Proton Center, Warrenville, Illinois
| | - James W. Snider
- Radiation Oncology, South Florida Proton Therapy Institute, Delray Beach, Florida
| | - Hualin Zhang
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Robert J. Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | | | - Daniel S. Hippe
- Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, Washington
| | | | - Xiaodong Wu
- Executive Medical Physics Associates, Miami, Florida
| | - Simon S. Lo
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - William F. Regine
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Charles B. Simone
- Department of Radiation Oncology, New York Proton Center, New York, New York
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10
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Zhang H, Ma L, Lim A, Ye J, Lukas L, Li H, Mayr NA, Chang EL. Dosimetric Validation for Prospective Clinical Trial of GRID Collimator-Based Spatially Fractionated Radiation Therapy: Dose Metrics Consistency and Heterogeneous Pattern Reproducibility. Int J Radiat Oncol Biol Phys 2024; 118:565-573. [PMID: 37660738 DOI: 10.1016/j.ijrobp.2023.08.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/19/2023] [Accepted: 08/25/2023] [Indexed: 09/05/2023]
Abstract
PURPOSE Dose heterogeneity within a tumor target is likely responsible for the biologic effects and local tumor control from spatially fractionated radiation therapy (SFRT). This study used a commercially available GRID-pattern dose mudulated nonuniform radiation therapy (GRID) collimator to assess the interplan variability of heterogeneity dose metrics in patients with various bulky tumor sizes and depths. METHODS AND MATERIALS The 3-dimensional heterogeneity metrics of 14 bulky tumors, ranging from 155 to 2161 cm3 in volume, 6 to 23 cm in equivalent diameter, and 3 to 13 cm in depth, and treated with GRID collimator-based SFRT were studied. A prescription dose of 15 Gy was given at the tumor center with 6 MV photons. The dose-volume histogram indices, dose heterogeneity parameters, and peak/valley dose ratios were derived; the equivalent uniform doses of cancer cells with various radiosensitivities in each plan were estimated. To account for the spatial fractionation, high dose core number density of the tumor target was defined and calculated. RESULTS Among 14 plans, the dose-volume histogram indices D5, D10, D50, D90, and D95 (doses covering 5%, 10%, 50%, 90%, and 95% of the target volume) were found within 10% variation. The dose ratio of D10/D90 also showed a moderate consistency (range, 3.9-5.0; mean, 4.4). The equivalent uniform doses were consistent, ranging from 4.3 to 5.5 Gy, mean 4.6 Gy, for radiosensitive cancer cells and from 5.8 to 6.9 Gy, mean 6.2 Gy, for radioresistant cancer cells. The high dose core number density was within 20% among all plans. CONCLUSIONS GRID collimator-based SFRT delivers a consistent heterogeneity dose distribution and high dose core density across bulky tumor plans. The interplan reproducibility and simplicity of GRID therapy may be useful for certain clinical indications and interinstitutional clinical trial design, and its heterogeneity metrics may help guide multileaf-collimator-based SFRT planning to achieve similar or further optimized dose distributions.
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Affiliation(s)
- Hualin Zhang
- Department of Radiation Oncology, University of Southern California, Los Angeles, California.
| | - Lijun Ma
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Andrew Lim
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Jason Ye
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Lauren Lukas
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Heng Li
- Department of Radiation Oncology and Molecular Radiation Sciences, John Hopkins University, Baltimore, Maryland
| | - Nina A Mayr
- College of Human Medicine, Michigan State University, East Lansing, Michigan
| | - Eric Lin Chang
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
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11
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Medici F, Strolin S, Castellucci P, Cilla S, Laghi V, Galietta E, Vadalà M, Strigari L, Morganti AG, Cammelli S. Complete metabolic response after Partially Ablative Radiotherapy (PAR) for bulky retroperitoneal liposarcoma: A case report. Radiol Case Rep 2024; 19:305-309. [PMID: 38028304 PMCID: PMC10656220 DOI: 10.1016/j.radcr.2023.10.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/01/2023] [Accepted: 10/08/2023] [Indexed: 12/01/2023] Open
Abstract
In the management of symptomatic inoperable retroperitoneal sarcomas (RPS), palliative radiotherapy (RT) is a potential treatment option. However, the efficacy of low doses used in palliative RT is limited in these radioresistant tumors. Therefore, exploring dose escalation strategies targeting specific regions of the tumor may enhance the therapeutic effect of RT in relieving or preventing symptoms. In this case report, we present the case of an 87-year-old patient with rapidly growing undifferentiated liposarcoma in the retroperitoneum, where surgical and systemic therapies were ruled out due to age and comorbidities. RT was administered using volumetric modulated arc therapy, delivering 20 Gy in 4 fractions twice daily to the macroscopic tumor and 40 Gy in 4 fractions twice daily (simultaneous integrated boost) to the central part of the tumor (Gross Tumor Volume minus 2 cm). An 18F-FDG-PET-CT scan performed after RT demonstrated a complete metabolic response throughout the entire tumor mass. Although the patient eventually succumbed to metastatic spread to the bone, liver, and lung after 9 months, no local disease progression or pain/obstructive symptoms were observed. This case highlights the technical and clinical feasibility of delivering ablative doses of RT to the central region of the tumor and suggests the potential for achieving a complete metabolic response and durable tumor control.
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Affiliation(s)
- Federica Medici
- Department of Medical and Surgical Sciences, DIMEC, Alma Mater Studiorum University of Bologna, Bologna, Italy
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Silvia Strolin
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Paolo Castellucci
- Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Savino Cilla
- Medical Physics Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Viola Laghi
- Department of Medical and Surgical Sciences, DIMEC, Alma Mater Studiorum University of Bologna, Bologna, Italy
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Erika Galietta
- Department of Medical and Surgical Sciences, DIMEC, Alma Mater Studiorum University of Bologna, Bologna, Italy
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Maria Vadalà
- Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Lidia Strigari
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Alessio Giuseppe Morganti
- Department of Medical and Surgical Sciences, DIMEC, Alma Mater Studiorum University of Bologna, Bologna, Italy
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Silvia Cammelli
- Department of Medical and Surgical Sciences, DIMEC, Alma Mater Studiorum University of Bologna, Bologna, Italy
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
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12
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Tucker WW, Mazur TR, Schmidt MC, Hilliard J, Badiyan S, Spraker MB, Kavanaugh JA. Script-based implementation of automatic grid placement for lattice stereotactic body radiation therapy. Phys Imaging Radiat Oncol 2024; 29:100549. [PMID: 38380154 PMCID: PMC10876586 DOI: 10.1016/j.phro.2024.100549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/26/2024] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Background and purpose Spatially fractionated radiation therapy (SFRT) has demonstrated promising clinical response in treating large tumors with heterogeneous dose distributions. Lattice stereotactic body radiation therapy (SBRT) is an SFRT technique that leverages inverse optimization to precisely localize regions of high and lose dose within disease. The aim of this study was to evaluate an automated heuristic approach to sphere placement in lattice SBRT treatment planning. Materials and methods A script-based algorithm for sphere placement in lattice SBRT based on rules described by protocol was implemented within a treatment planning system. The script was applied to 22 treated cases and sphere distributions were compared with manually placed spheres in terms of number of spheres, number of protocol violations, and time required to place spheres. All cases were re-planned using script-generated spheres and plan quality was compared with clinical plans. Results The mean number of spheres placed excluding those that violate rules was greater using the script (13.8) than that obtained by either dosimetrist (10.8 and 12.0, p < 0.001 and p = 0.003) or physicist (12.7, p = 0.061). The mean time required to generate spheres was significantly less using the script (2.5 min) compared to manual placement by dosimetrists (25.0 and 29.9 min) and physicist (19.3 min). Plan quality indices were similar in all cases with no significant differences, and OAR constraints remained met on all plans except two. Conclusion A script placed spheres for lattice SBRT according to institutional protocol rules. The script-produced placement was superior to that of manually-specified spheres, as characterized by sphere number and rule violations.
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Affiliation(s)
- Wesley W. Tucker
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO 63110 USA
| | - Thomas R. Mazur
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO 63110 USA
| | - Matthew C. Schmidt
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO 63110 USA
| | - Jessica Hilliard
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO 63110 USA
| | - Shahed Badiyan
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO 63110 USA
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13
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Lu Q, Yan W, Zhu A, Tubin S, Mourad WF, Yang J. Combining spatially fractionated radiation therapy (SFRT) and immunotherapy opens new rays of hope for enhancing therapeutic ratio. Clin Transl Radiat Oncol 2024; 44:100691. [PMID: 38033759 PMCID: PMC10684810 DOI: 10.1016/j.ctro.2023.100691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/04/2023] [Accepted: 10/15/2023] [Indexed: 12/02/2023] Open
Abstract
Spatially Fractionated Radiation Therapy (SFRT) is a form of radiotherapy that delivers a single large dose of radiation within the target volume in a heterogeneous pattern with regions of peak dosage and regions of under dosage. SFRT types can be defined by how the heterogeneous pattern of radiation is obtained. Immune checkpoint inhibitors (ICIs) have been approved for various malignant tumors and are widely used to treat patients with metastatic cancer. The efficacy of ICI monotherapy is limited due to the "cold" tumor microenvironment. Fractionated radiotherapy can achieve higher doses per fraction to the target tumor, and induce immune activation (immodulate tumor immunogenicity and microenvironment). Therefore, coupling ICI therapy and fractionated radiation therapy could significantly improve the outcome of metastatic cancer. This review focuses on both preclinical and clinical studies that use a combination of radiotherapy and ICI therapy in cancer.
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Affiliation(s)
- Qiuxia Lu
- Foshan Fosun Chancheng Hospital, P.R. China
- Junxin Precision Oncology Group, P.R. China
| | - Weisi Yan
- Baptist Health System, Lexington, KY, United States
- Junxin Precision Oncology Group, P.R. China
| | - Alan Zhu
- Mayo Clinic Alix School of Medicine, Scottsdale, AZ, United States
| | - Slavisa Tubin
- Albert Einstein Collage of Medicine New York, Center for Ion Therapy, Medaustron, Austria
| | - Waleed F. Mourad
- Department of Radiation Medicine Markey Cancer Center, University of Kentucky - College of Medicine, United States
| | - Jun Yang
- Foshan Fosun Chancheng Hospital, P.R. China
- Junxin Precision Oncology Group, P.R. China
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14
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Clements N, Esplen N, Bazalova-Carter M. A feasibility study of ultra-high dose rate mini-GRID therapy using very-high-energy electron beams for a simulated pediatric brain case. Phys Med 2023; 112:102637. [PMID: 37454482 DOI: 10.1016/j.ejmp.2023.102637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/09/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
Ultra-high dose rate (UHDR, >40 Gy/s), spatially-fractionated minibeam GRID (mini-GRID) therapy using very-high-energy electrons (VHEE) was investigated using Monte Carlo simulations. Multi-directional VHEE treatments with and without mini-GRID-fractionation were compared to a clinical 6 MV volumetric modulated arc therapy (VMAT) plan for a pediatric glioblastoma patient using dose-volume histograms, volume-averaged dose rates in critical patient structures, and planning target volume D98s. Peak-to-valley dose ratios (PVDRs) and dose rates in organs at risk (OARs) were evaluated due to their relevance for normal-tissue sparing in FLASH and spatially-fractionated techniques. Depths of convergence, defined where the PVDR is first ≤1.1, and depths at which dose rates fall below the UHDR threshold were also evaluated. In a water phantom, the VHEE mini-GRID treatments presented a surface (5 mm depth) PVDR of (51±2) and a depth of convergence of 42 mm at 150 MeV and a surface PVDR of (33±1) with a depth of convergence of 57 mm at 250 MeV. For a pediatric GBM case, VHEE treatments without mini-GRID-fractionation produced 25% and 22% lower volume-averaged doses to OARs compared to the 6 MV VMAT plan and 8/9 and 9/9 of the patient structures were exposed to volume-averaged dose rates >40 Gy/s for the 150 MeV and 250 MeV plans, respectively. The 150 MeV and 250 MeV mini-GRID treatments produced 17% and 38% higher volume-averaged doses to OARs and 3/9 patient structures had volume-averaged dose rates above 40 Gy/s. VHEE mini-GRID plans produced many comparable dose metrics to the clinical VMAT plan, encouraging further optimization.
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Affiliation(s)
- Nathan Clements
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada.
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
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15
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Tubin S, Vozenin M, Prezado Y, Durante M, Prise K, Lara P, Greco C, Massaccesi M, Guha C, Wu X, Mohiuddin M, Vestergaard A, Bassler N, Gupta S, Stock M, Timmerman R. Novel unconventional radiotherapy techniques: Current status and future perspectives - Report from the 2nd international radiation oncology online seminar. Clin Transl Radiat Oncol 2023; 40:100605. [PMID: 36910025 PMCID: PMC9996385 DOI: 10.1016/j.ctro.2023.100605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023] Open
Abstract
•Improvement of therapeutic ratio by novel unconventional radiotherapy approaches.•Immunomodulation using high-dose spatially fractionated radiotherapy.•Boosting radiation anti-tumor effects by adding an immune-mediated cell killing.
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Affiliation(s)
- S. Tubin
- Medaustron Center for Ion Therapy, Marie-Curie Strasse 5, Wiener Neustadt 2700, Austria
- Corresponding author.
| | - M.C. Vozenin
- Radiation Oncology Laboratory, Radiation Oncology Service, Oncology Department, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Y. Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay 91400, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay 91400, France
| | - M. Durante
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, Darmstadt 64291, Germany
- Technsiche Universität Darmstadt, Institute for Condensed Matter Physics, Darmstadt, Germany
| | - K.M. Prise
- Patrick G Johnston Centre for Cancer Research Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, United Kingdom
| | - P.C. Lara
- Canarian Comprehensive Cancer Center, San Roque University Hospital & Fernando Pessoa Canarias University, C/Dolores de la Rocha 9, Las Palmas GC 35001, Spain
| | - C. Greco
- Department of Radiation Oncology Champalimaud Foundation, Av. Brasilia, Lisbon 1400-038, Portugal
| | - M. Massaccesi
- UOC di Radioterapia Oncologica, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - C. Guha
- Montefiore Medical Center Radiation Oncology, 111 E 210th St, New York, NY, United States
| | - X. Wu
- Executive Medical Physics Associates, 19470 NE 22nd Road, Miami, FL 33179, United States
| | - M.M. Mohiuddin
- Northwestern Medicine Cancer Center Warrenville and Northwestern Medicine Proton Center, 4455 Weaver Pkwy, Warrenville, IL 60555, United States
| | - A. Vestergaard
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - N. Bassler
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - S. Gupta
- The Loop Immuno-Oncology Laboratory, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, United States
| | - M. Stock
- Medaustron Center for Ion Therapy, Marie-Curie Strasse 5, Wiener Neustadt 2700, Austria
- Karl Landsteiner University of Health Sciences, Marie-Curie Strasse 5, Wiener Neustadt 2700, Austria
| | - R. Timmerman
- Department of Radiation Oncology, University of Texas, Southwestern Medical Center, Inwood Road Dallas, TX 2280, United States
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16
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Hatoum GF, Temple HT, Garcia SA, Zheng Y, Kfoury F, Kinley J, Wu X. Neoadjuvant Radiation Therapy with Interdigitated High-Dose LRT for Voluminous High-Grade Soft-Tissue Sarcoma. Cancer Manag Res 2023; 15:113-122. [PMID: 36776730 PMCID: PMC9910204 DOI: 10.2147/cmar.s393934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Purpose To report a case of large extremity soft tissue sarcoma (2933 cc), safely treated with a novel approach of interdigitating high-dose LATTICE radiation therapy (LRT) with standard radiation therapy as a neoadjuvant treatment to surgery. Patients and Methods Four sessions of high-dose LRT were delivered in a weekly interval, interdigitated with standard radiation therapy. The LRT plan consisted of 15 high-dose vertices receiving a dose >12 Gy per session, with 2-3 Gy to the peripheral margin of the tumor. The patient underwent surgical excision 2 months after the new regimen of induction radiation therapy. Results and Discussion The patient tolerated the radiation therapy regimen well. The post-operative assessment revealed a negative surgical margin and over 95% necrosis of the total tumor volume. The post-surgical wound complication was mitigated by outpatient wound care. Interdigitating multiple sessions of high-dose LATTICE radiation treatments with standard neoadjuvant radiation therapy as a neoadjuvant therapy for soft tissue sarcoma was feasible and did not incur additional toxicity in this clinical case. A phase-I/II trial will be conducted to further evaluate the toxicity and efficacy of the new treatment strategy with the intent to increase the rate of pathologic necrosis, which has been shown to positively correlate with the overall survival.
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Affiliation(s)
- Georges F Hatoum
- Department of Radiation Oncology, HCA Florida JFK Medical Center Comprehensive Cancer Institute, Lake Worth, FL, USA
| | - H Thomas Temple
- Department of Orthopedic Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Silvio A Garcia
- Department of Radiation Oncology, HCA Florida JFK Medical Center Comprehensive Cancer Institute, Lake Worth, FL, USA
| | - Yi Zheng
- Department of Radiation Oncology, HCA Florida JFK Medical Center Comprehensive Cancer Institute, Lake Worth, FL, USA,Department of Research and Development, Executive Medical Physics Associates, North Miami Beach, FL, USA
| | - Fouad Kfoury
- Pharmacy Department, South Miami Hospital, South Miami, FL, USA
| | - Jill Kinley
- Department of Clinical Research, HCA Florida JFK Medical Center, Atlantis, FL, USA
| | - Xiaodong Wu
- Department of Radiation Oncology, HCA Florida JFK Medical Center Comprehensive Cancer Institute, Lake Worth, FL, USA,Department of Research and Development, Executive Medical Physics Associates, North Miami Beach, FL, USA,Correspondence: Xiaodong Wu, Executive Medical Physics Associates, 19470 NE 22nd Road, North Miami Beach, FL, 33179, USA, Tel +1 305 775 0333, Email
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17
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Ertan F, Yeginer M, Zorlu F. Dosimetric Performance Evaluation of MLC-based and Cone-based 3D Spatially Fractionated LATTICE Radiotherapy. Radiat Res 2023; 199:161-169. [PMID: 36580642 DOI: 10.1667/rade-22-00020.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 11/11/2022] [Indexed: 12/31/2022]
Abstract
This study aims to dosimetrically compare multi-leaf collimator (MLC)-based and cone-based 3D LATTICE radiotherapy (LRT) plans. Valley-peak ratios were evaluated using seven different 3D LATTICE designs. Target volumes of 8 cm and 12 cm were defined on the RANDO phantom. Valley-peak dose patterns were obtained by creating high-dose vertices in the target volumes. By changing the vertex diameter, vertices separation, and volume ratio, seven different LATTICE designs were generated. Treatment plans were implemented using CyberKnife and Varian RapidArc. Thermoluminescent dosimeter (TLD), EBT3 films, and electronic portal-imaging device (EPID) were employed for dosimetric treatment verification, and measured doses were compared to calculated doses. By changing the vertex diameter and vertices separation, the valley-peak ratio was exhibited little difference between the two systems. By changing the vertex diameter and volume ratio, the valley-peak ratio was observed nearly the same for the two systems. The film, TLD, and EPID dosimetry showed good agreement between the calculated and measured doses. Based on the results, we concluded that although smaller valley-peak ratios were obtained with cone-based plans, the dose-volume histograms were comparable in both systems. Also, when we evaluated the treatment duration, the MLC-based plans were more appropriate to apply the treatment in a single fraction.
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Affiliation(s)
- Ferihan Ertan
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey.,Dr. Abdurrahman Yurtaslan Ankara Oncology Teaching and Research Hospital, 06200, Ankara, Turkey
| | - Mete Yeginer
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
| | - Faruk Zorlu
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
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18
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Arous D, Lie JL, Håland BV, Børsting M, Edin NFJ, Malinen E. 2D mapping of radiation dose and clonogenic survival for accurate assessment of in vitroX-ray GRID irradiation effects. Phys Med Biol 2023; 68. [PMID: 36580679 DOI: 10.1088/1361-6560/acaf20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 12/29/2022] [Indexed: 12/30/2022]
Abstract
Spatially fractionated radiation therapy (SFRT or GRID) is an approach to deliver high local radiation doses in an 'on-off' pattern. To better appraise the radiobiological effects from GRID, a framework to link local radiation dose to clonogenic survival needs to be developed. A549 lung cancer cells were irradiated in T25 cm2flasks using 220 kV x-rays with an open field or through a tungsten GRID collimator with periodical 5 mm openings and 10 mm blockings. Delivered nominal doses were 2, 5, and 10 Gy. A novel approach for image segmentation was used to locate the centroid of surviving colonies in scanned images of the cell flasks. GafchromicTMfilm dosimetry (GFD) and FLUKA Monte Carlo (MC) simulations were employed to map the dose at each surviving colony centroid. Fitting the linear-quadratic (LQ) function to clonogenic survival data for open field irradiation, the expected survival level at a given dose level was calculated. The expected survival levels were then mapped together with the observed levels in the GRID-irradiated flasks. GFD and FLUKA MC gave similar dose distributions, with a mean peak-to-valley dose ratio of about 5. LQ-parameters for open field irradiation gaveα=0.24±0.02Gy-1andβ=0.019±0.002Gy-2. The mean relative percentage deviation between observed and predicted survival in the (peak; valley) dose regions was (4.6; 3.1) %, (26.6; -1.0) %, and (129.8; -2.3) % for 2, 5 and 10 Gy, respectively. In conclusion, a framework for mapping of surviving colonies following GRID irradiation together with predicted survival levels from homogeneous irradiation was presented. For the given cell line, our findings indicate that GRID irradiation causes reduced survival in the peak regions compared to an open field configuration.
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Affiliation(s)
- Delmon Arous
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316, Oslo, Norway.,Department of Medical Physics, The Norwegian Radium Hospital, Oslo University Hospital, PO Box 4953 Nydalen, N-0424 Oslo, Norway
| | - Jacob Larsen Lie
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316, Oslo, Norway
| | - Bjørg Vårli Håland
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316, Oslo, Norway
| | - Magnus Børsting
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316, Oslo, Norway
| | | | - Eirik Malinen
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316, Oslo, Norway.,Department of Medical Physics, The Norwegian Radium Hospital, Oslo University Hospital, PO Box 4953 Nydalen, N-0424 Oslo, Norway
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19
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Halthore A, Fellows Z, Tran A, Deville C, Wright JL, Meyer J, Li H, Sheikh K. Treatment Planning of Bulky Tumors Using Pencil Beam Scanning Proton GRID Therapy. Int J Part Ther 2022; 9:40-49. [PMID: 36721485 PMCID: PMC9875826 DOI: 10.14338/ijpt-22-00028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 11/02/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose To compare spatially fractionated radiation therapy (GRID) treatment planning techniques using proton pencil-beam-scanning (PBS) and photon therapy. Materials and Methods PBS and volumetric modulated arc therapy (VMAT) GRID plans were retrospectively generated for 5 patients with bulky tumors. GRID targets were arranged along the long axis of the gross tumor, spaced 2 and 3 cm apart, and treated with a prescription of 18 Gy. PBS plans used 2- to 3-beam multiple-field optimization with robustness evaluation. Dosimetric parameters including peak-to-edge ratio (PEDR), ratio of dose to 90% of the valley to dose to 10% of the peak VPDR(D90/D10), and volume of normal tissue receiving at least 5 Gy (V5) and 10 Gy (V10) were calculated. The peak-to-valley dose ratio (PVDR), VPDR(D90/D10), and organ-at-risk doses were prospectively assessed in 2 patients undergoing PBS-GRID with pretreatment quality assurance computed tomography (QACT) scans. Results PBS and VMAT GRID plans were generated for 5 patients with bulky tumors. Gross tumor volume values ranged from 826 to 1468 cm3. Peak-to-edge ratio for PBS was higher than for VMAT for both spacing scenarios (2-cm spacing, P = .02; 3-cm spacing, P = .01). VPDR(D90/D10) for PBS was higher than for VMAT (2-cm spacing, P = .004; 3-cm spacing, P = .002). Normal tissue V5 was lower for PBS than for VMAT (2-cm spacing, P = .03; 3-cm spacing, P = .02). Normal tissue mean dose was lower with PBS than with VMAT (2-cm spacing, P = .03; 3-cm spacing, P = .02). Two patients treated using PBS GRID and assessed with pretreatment QACT scans demonstrated robust PVDR, VPDR(D90/D10), and organs-at-risk doses. Conclusions The PEDR was significantly higher for PBS than VMAT plans, indicating lower target edge dose. Normal tissue mean dose was significantly lower with PBS than VMAT. PBS GRID may result in lower normal tissue dose compared with VMAT plans, allowing for further dose escalation in patients with bulky disease.
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Affiliation(s)
- Aditya Halthore
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
,Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Zachary Fellows
- Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Anh Tran
- Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Curtiland Deville
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
,Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Jean L. Wright
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
,Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Jeffrey Meyer
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Heng Li
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
,Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
| | - Khadija Sheikh
- Department of Radiation Oncology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
,Department of Radiation Oncology, The Johns Hopkins Proton Center, Washington, DC, USA
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20
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Clements N, Bazalova-Carter M, Esplen N. Monte Carlo optimization of a GRID collimator for preclinical megavoltage ultra-high dose rate spatially-fractionated radiation therapy. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac8c1a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/23/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. A 2-dimensional pre-clinical SFRT (GRID) collimator was designed for use on the ultra-high dose rate (UHDR) 10 MV ARIEL beamline at TRIUMF. TOPAS Monte Carlo simulations were used to determine optimal collimator geometry with respect to various dosimetric quantities. Approach. The GRID-averaged peak-to-valley dose ratio (PVDR) and mean dose rate of the peaks were investigated with the intent of maximizing both values in a given design. The effects of collimator thickness, focus position, septal width, and hole width on these metrics were found by testing a range of values for each parameter on a cylindrical GRID collimator. For each tested collimator geometry, photon beams with energies of 10, 5, and 1 MV were transported through the collimator and dose rates were calculated at various depths in a water phantom located 1.0 cm from the collimator exit. Main results. In our optimization, hole width proved to be the only collimator parameter which increased both PVDR and peak dose rates. From the optimization results, it was determined that our optimized design would be one which achieves the maximum dose rate for a PVDR
≥
5
at 10 MV. Ultimately, this was achieved using a collimator with a thickness of 75 mm, 0.8 mm septal and hole widths, and a focus position matched to the beam divergence. This optimized collimator maintained the PVDR of 5 in the phantom between water depths of 0–10 cm at 10 MV and had a mean peak dose rate of
3.06
±
0.02
Gy
s
−
1
at 0–1 cm depth. Significance. We have investigated the impact of various GRID-collimator design parameters on the dose rate and spatial fractionation of 10, 5, and 1 MV photon beams. The optimized collimator design for the 10 MV ultra-high dose rate photon beam could become a useful tool for radiobiology studies synergizing the effects of ultra-high dose rate (FLASH) delivery and spatial fractionation.
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21
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An International Consensus on the Design of Prospective Clinical–Translational Trials in Spatially Fractionated Radiation Therapy for Advanced Gynecologic Cancer. Cancers (Basel) 2022; 14:cancers14174267. [PMID: 36077802 PMCID: PMC9454841 DOI: 10.3390/cancers14174267] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Spatially fractionated radiation therapy (SFRT) delivers intentionally heterogenous dose to tumors. This is a major departure from current radiation therapy, which strives for uniform dose. Early pilot experience suggests promising treatment outcomes with SFRT in patients with challenging bulky tumors, including gynecologic cancer. Well-conducted prospective multi-institutional clinical trials are now needed to further test SFRT as a treatment modality. However, clinical trial development is hampered by the variabilities in SFRT approach and the overall unfamiliarity with heterogeneous dosing. A broad consensus among SFRT experts, potential investigators, and the wider radiation oncology community is needed so that clinical trials in SFRT can be successfully designed and carried out. We developed an international consensus guideline for the design parameters of clinical/translational trials in SFRT for gynecologic cancer. High-to-moderate consensus was achieved, and harmonized fundamental design parameters for SFRT trials in advanced gynecologic cancer were defined. Abstract Despite the unexpectedly high tumor responses and limited treatment-related toxicities observed with SFRT, prospective multi-institutional clinical trials of SFRT are still lacking. High variability of SFRT technologies and methods, unfamiliar complex dose and prescription concepts for heterogeneous dose and uncertainty regarding systemic therapies present major obstacles towards clinical trial development. To address these challenges, the consensus guideline reported here aimed at facilitating trial development and feasibility through a priori harmonization of treatment approach and the full range of clinical trial design parameters for SFRT trials in gynecologic cancer. Gynecologic cancers were evaluated for the status of SFRT pilot experience. A multi-disciplinary SFRT expert panel for gynecologic cancer was established to develop the consensus through formal panel review/discussions, appropriateness rank voting and public comment solicitation/review. The trial design parameters included eligibility/exclusions, endpoints, SFRT technology/technique, dose/dosimetric parameters, systemic therapies, patient evaluations, and embedded translational science. Cervical cancer was determined as the most suitable gynecologic tumor for an SFRT trial. Consensus emphasized standardization of SFRT dosimetry/physics parameters, biologic dose modeling, and specimen collection for translational/biological endpoints, which may be uniquely feasible in cervical cancer. Incorporation of brachytherapy into the SFRT regimen requires additional pre-trial pilot investigations. Specific consensus recommendations are presented and discussed.
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22
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Impressive Results after "Metabolism-Guided" Lattice Irradiation in Patients Submitted to Palliative Radiation Therapy: Preliminary Results of LATTICE_01 Multicenter Study. Cancers (Basel) 2022; 14:cancers14163909. [PMID: 36010902 PMCID: PMC9406022 DOI: 10.3390/cancers14163909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/05/2022] [Accepted: 08/11/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose: To evaluate feasibility, toxicities, and clinical response in Stage IV patients treated with palliative “metabolism-guided” lattice technique. Patients and Methods: From June 2020 to December 2021, 30 consecutive clinical stage IV patients with 31 bulky lesions were included in this study. All patients received palliative irradiation consisting of a spatially fractionated high radiation dose delivered in spherical deposits (vertices, Vs) within the bulky disease. The Vs were placed at the edges of tumor areas with different metabolisms at the PET exam following a non-geometric arrangement. Precisely, the Vs overlapped the interfaces between the tumor areas of higher 18F-FDG uptake (>75% SUV max) and areas with lower 18F-FDG uptake. A median dose of 15 Gy/1 fraction (range 10−27 Gy in 1/3 fractions) was delivered to the Vs. Within 7 days after the Vs boost, all the gross tumor volume (GTV) was homogeneously treated with hypo-fractionated radiation therapy (RT). Results: The rate of symptomatic response was 100%, and it was observed immediately after lattice RT delivery in 3/30 patients, while 27/30 patients had a symptomatic response within 8 days from the end of GTV irradiation. Radiation-related acute grade ≥1 toxicities were observed in 6/30 (20%) patients. The rate of overall clinical response was 89%, including 23% of complete remission. The 1-year overall survival rate was 86.4%. Conclusions: “Metabolism-guided” lattice radiotherapy is feasible and well-tolerated, being able to yield very impressive results both in terms of symptom relief and overall clinical response rate in stage IV bulky disease patients. These preliminary results seem to indicate that this kind of therapy could emerge as the best therapeutic option for this patient setting.
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23
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McAuley GA, Lim CJ, Teran AV, Slater JD, Wroe AJ. Monte Carlo evaluation of high-gradient magnetically focused planar proton minibeams in a passive nozzle. Phys Med Biol 2022; 67. [PMID: 35421853 DOI: 10.1088/1361-6560/ac678b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/14/2022] [Indexed: 11/12/2022]
Abstract
Objective. To investigate the potential of using a single quadrupole magnet with a high magnetic field gradient to create planar minibeams suitable for clinical applications of proton minibeam radiation therapy.Approach. We performed Monte Carlo simulations involving single quadrupole Halbach cylinders in a passively scattered nozzle in clinical use for proton therapy. Pencil beams produced by the nozzle of 10-15 mm initial diameters and particle range of ∼10-20 cm in water were focused by magnets with field gradients of 225-350 T m-1and cylinder lengths of 80-110 mm to produce very narrow elongated (planar) beamlets. The corresponding dose distributions were scored in a water phantom. Composite minibeam dose distributions composed from three beamlets were created by laterally shifting copies of the single beamlet distribution to either side of a central beamlet. Modulated beamlets (with 18-30 mm nominal central SOBP) and corresponding composite dose distributions were created in a similar manner. Collimated minibeams were also compared with beams focused using one magnet/particle range combination.Main results. The focusing magnets produced planar beamlets with minimum lateral FWHM of ∼1.1-1.6 mm. Dose distributions composed from three unmodulated beamlets showed a high degree of proximal spatial fractionation and a homogeneous target dose. Maximal peak-to-valley dose ratios (PVDR) for the unmodulated beams ranged from 32 to 324, and composite modulated beam showed maximal PVDR ranging from 32 to 102 and SOBPs with good target dose coverage.Significance.Advantages of the high-gradient magnets include the ability to focus beams with phase space parameters that reflect beams in operation today, and post-waist particle divergence allowing larger beamlet separations and thus larger PVDR. Our results suggest that high gradient quadrupole magnets could be useful to focus beams of moderate emittance in clinical proton therapy.
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Affiliation(s)
- Grant A McAuley
- Department of Radiation Medicine, Loma Linda University, Loma Linda CA, United States of America
| | - Crystal J Lim
- School of Medicine, Loma Linda University, Loma Linda, CA United States of America
| | - Anthony V Teran
- Department of Radiation Medicine, Loma Linda University, Loma Linda CA, United States of America.,Orange County CyberKnife and Radiation Oncology Center, Fountain Valley, CA, United States of America
| | - Jerry D Slater
- Department of Radiation Medicine, Loma Linda University, Loma Linda CA, United States of America
| | - Andrew J Wroe
- School of Medicine, Loma Linda University, Loma Linda, CA United States of America.,Department of Radiation Oncology, Miami Cancer Institute, Miami, FL, United States of America.,Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, United States of America
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24
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Pokhrel D, Bernard ME, Mallory R, St Clair W, Kudrimoti M. Conebeam CT-guided 3D MLC-based spatially fractionated radiation therapy for bulky masses. J Appl Clin Med Phys 2022; 23:e13608. [PMID: 35446479 PMCID: PMC9121033 DOI: 10.1002/acm2.13608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/03/2022] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
For fast, safe, and effective management of large and bulky (≥8 cm) non‐resectable tumors, we have developed a conebeam CT‐guided three‐dimensional (3D)‐conformal MLC‐based spatially fractionated radiation therapy (SFRT) treatment. Using an in‐house MLC‐fitting algorithm, Millennium 120 leaves were fitted to the gross tumor volume (GTV) generating 1‐cm diameter holes at 2‐cm center‐to‐center distance at isocenter. SFRT plans of 15 Gy were generated using four to six coplanar crossfire gantry angles 60° apart with a 90° collimator, differentially weighted with 6‐ or 10‐MV beams. A dose was calculated using AcurosXB algorithm, generating sieve‐like dose channels without post‐processing the physician‐drawn GTV contour within an hour of CT simulation allowing for the same day treatment. In total, 50 extracranial patients have been planned and treated using this method, comprising multiple treatment sites. This novel MLC‐fitting algorithm provided excellent dose parameters with mean GTV (V7.5 Gy) and mean GTV doses of 53.2% and 7.9 Gy, respectively, for 15 Gy plans. Average peak‐to‐valley dose ratio was 3.2. Mean beam‐on time was 3.32 min, and treatment time, including patient setup and CBCT to beam‐off, was within 15 min. Average 3D couch correction from original skin‐markers was <1.0 cm. 3D MLC‐based SFRT plans enhanced target dose for bulky masses, including deep‐seated large tumors while protecting skin and adjacent critical organs. Additionally, it provides the same day, safe, effective, and convenient treatment by eliminating the risk to therapists and patients from heavy gantry‐mounted physical GRID‐block—we recommend other centers to use this simple and clinically useful method. This rapid SFRT planning technique is easily adoptable in any radiation oncology clinic by eliminating the need for plan optimization and patient‐specific quality assurance times while providing dosimetry information in the treatment planning system. This potentially allows for dose‐escalation to deep‐seated masses to debulk unresectable large tumors providing an option for neoadjuvant treatment. An outcome study of clinical trial is underway.
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Affiliation(s)
- Damodar Pokhrel
- Department of Radiation, Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Mark E Bernard
- Department of Radiation, Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Richard Mallory
- Department of Radiation, Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - William St Clair
- Department of Radiation, Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Mahesh Kudrimoti
- Department of Radiation, Medicine, University of Kentucky, Lexington, Kentucky, USA
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25
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Moghaddasi L, Reid P, Bezak E, Marcu LG. Radiobiological and Treatment-Related Aspects of Spatially Fractionated Radiotherapy. Int J Mol Sci 2022; 23:3366. [PMID: 35328787 PMCID: PMC8954016 DOI: 10.3390/ijms23063366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/13/2022] [Accepted: 03/17/2022] [Indexed: 11/17/2022] Open
Abstract
The continuously evolving field of radiotherapy aims to devise and implement techniques that allow for greater tumour control and better sparing of critical organs. Investigations into the complexity of tumour radiobiology confirmed the high heterogeneity of tumours as being responsible for the often poor treatment outcome. Hypoxic subvolumes, a subpopulation of cancer stem cells, as well as the inherent or acquired radioresistance define tumour aggressiveness and metastatic potential, which remain a therapeutic challenge. Non-conventional irradiation techniques, such as spatially fractionated radiotherapy, have been developed to tackle some of these challenges and to offer a high therapeutic index when treating radioresistant tumours. The goal of this article was to highlight the current knowledge on the molecular and radiobiological mechanisms behind spatially fractionated radiotherapy and to present the up-to-date preclinical and clinical evidence towards the therapeutic potential of this technique involving both photon and proton beams.
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Affiliation(s)
- Leyla Moghaddasi
- Department of Medical Physics, Austin Health, Ballarat, VIC 3350, Australia;
- School of Physical Sciences, University of Adelaide, Adelaide, SA 5001, Australia;
| | - Paul Reid
- Radiation Health, Environment Protection Authority, Adelaide, SA 5000, Australia;
| | - Eva Bezak
- School of Physical Sciences, University of Adelaide, Adelaide, SA 5001, Australia;
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Loredana G. Marcu
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia
- Faculty of Informatics and Science, University of Oradea, 1 Universitatii Str., 410087 Oradea, Romania
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26
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Mayr NA, Snider JW, Regine WF, Mohiuddin M, Hippe DS, Peñagarícano J, Mohiuddin M, Kudrimoti MR, Zhang H, Limoli CL, Le QT, Simone CB. An International Consensus on the Design of Prospective Clinical–Translational Trials in Spatially Fractionated Radiation Therapy. Adv Radiat Oncol 2022; 7:100866. [PMID: 35198833 PMCID: PMC8843999 DOI: 10.1016/j.adro.2021.100866] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/12/2021] [Indexed: 12/17/2022] Open
Abstract
Purpose Spatially fractionated radiation therapy (SFRT), which delivers highly nonuniform dose distributions instead of conventionally practiced homogeneous tumor dose, has shown high rates of clinical response with minimal toxicities in large-volume primary or metastatic malignancies. However, prospective multi-institutional clinical trials in SFRT are lacking, and SFRT techniques and dose parameters remain variable. Agreement on dose prescription, technical administration, and clinical and translational design parameters for SFRT trials is essential to enable broad participation and successful accrual to rigorously test the SFRT approach. We aimed to develop a consensus for the design of multi-institutional clinical trials in SFRT, tailored to specific primary tumor sites, to help facilitate development and enhance the feasibility of such trials. Methods and Materials Primary tumor sites with sufficient pilot experience in SFRT were identified, and fundamental trial design questions were determined. For each tumor site, a comprehensive consensus effort was established through disease-specific expert panels. Clinical trial design criteria included eligibility, SFRT technology and technique, dose and fractionation, target- and normal-tissue dose parameters, systemic therapies, clinical trial endpoints, and translational science considerations. Iterative appropriateness rank voting, expert panel consensus reviews and discussions, and public comment posting were used for consensus development. Results Clinical trial criteria were developed for head and neck cancer and soft-tissue sarcoma. Final consensus among the 22 trial design categories each (a total of 163 criteria) was high to moderate overall. Uniform patient cohorts of advanced bulky disease, standardization of SFRT technologies and dosimetry and physics parameters, and collection of translational correlates were considered essential to trial design. Final guideline recommendations and the degree of agreement are presented and discussed. Conclusions This consensus provides design guidelines for the development of prospective multi-institutional clinical trials testing SFRT in advanced head and neck cancer and soft-tissue sarcoma through in-advance harmonization of the fundamental clinical trial design among SFRT experts, potential investigators, and the SFRT community.
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Affiliation(s)
- Nina A. Mayr
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
- Tumor Heterogeneity Imaging and Radiomics Laboratory, University of Washington School of Medicine, Seattle, Washington
- Corresponding author: Nina A. Mayr, MD
| | - James W. Snider
- Department of Radiation Oncology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama
| | - William F. Regine
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Majid Mohiuddin
- Radiation Oncology Consultants and Northwestern Proton Center, Warrenville, Illinois
| | - Daniel S. Hippe
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | | | | | - Mahesh R. Kudrimoti
- Department of Radiation Medicine, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Hualin Zhang
- Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California School of Medicine, Irvine, Irvine, California
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Charles B. Simone
- Department of Radiation Oncology, New York Proton Center, New York, New York
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27
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Johnson TR, Bassil AM, Williams NT, Brundage S, Kent CL, Palmer G, Mowery YM, Oldham M. An investigation of kV mini-GRID spatially fractionated radiation therapy: dosimetry and preclinical trial. Phys Med Biol 2022; 67:10.1088/1361-6560/ac508c. [PMID: 35100573 PMCID: PMC9167045 DOI: 10.1088/1361-6560/ac508c] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/31/2022] [Indexed: 11/11/2022]
Abstract
Objective. To develop and characterize novel methods of extreme spatially fractionated kV radiation therapy (including mini-GRID therapy) and to evaluate efficacy in the context of a pre-clinical mouse study.Approach. Spatially fractionated GRIDs were precision-milled from 3 mm thick lead sheets compatible with mounting on a 225 kVp small animal irradiator (X-Rad). Three pencil-beam GRIDs created arrays of 1 mm diameter beams, and three 'bar' GRIDs created 1 × 20 mm rectangular fields. GRIDs projected 20 × 20 mm2fields at isocenter, and beamlets were spaced at 1, 1.25, and 1.5 mm, respectively. Peak-to-valley ratios and dose distributions were evaluated with Gafchromic film. Syngeneic transplant tumors were induced by intramuscular injection of a soft tissue sarcoma cell line into the gastrocnemius muscle of C57BL/6 mice. Tumor-bearing mice were randomized to four groups: unirradiated control, conventional irradiation of entire tumor, GRID therapy, and hemi-irradiation (half-beam block, 50% tumor volume treated). All irradiated mice received a single fraction of 15 Gy.Results. High peak-to-valley ratios were achieved (bar GRIDs: 11.9 ± 0.9, 13.6 ± 0.4, 13.8 ± 0.5; pencil-beam GRIDs: 18.7 ± 0.6, 26.3 ± 1.5, 31.0 ± 3.3). Pencil-beam GRIDs could theoretically spare more intra-tumor immune cells than bar GRIDs, but they treat less tumor tissue (3%-4% versus 19%-23% area receiving 90% prescription, respectively). Bar GRID and hemi-irradiation treatments significantly delayed tumor growth (P < 0.05), but not as much as a conventional treatment (P < 0.001). No significant difference was found in tumor growth delay between GRID and hemi-irradiation.Significance. High peak-to-valley ratios were achieved with kV grids: two-to-five times higher than values reported in literature for MV grids. GRID irradiation and hemi-irradiation delayed tumor growth, but neither was as effective as conventional whole tumor uniform dose treatment. Single fraction GRID therapy could not initiate an anti-cancer immune response strong enough to match conventional RT outcomes, but follow-up studies will evaluate the combination of mini-GRID with immune checkpoint blockade.
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Affiliation(s)
- Timothy R Johnson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America,Authors to whomany correspondence should be addressed. , and
| | - Alex M Bassil
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Nerissa T Williams
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Simon Brundage
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Collin L Kent
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Greg Palmer
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Yvonne M Mowery
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America,Department of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC, United States of America,Authors to whomany correspondence should be addressed. , and
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America,Authors to whomany correspondence should be addressed. , and
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28
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A Dosimetric Parameter Reference Look-Up Table for GRID Collimator-Based Spatially Fractionated Radiation Therapy. Cancers (Basel) 2022; 14:cancers14041037. [PMID: 35205785 PMCID: PMC8869958 DOI: 10.3390/cancers14041037] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/08/2022] [Accepted: 02/15/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Dose prescription for the inhomogeneous dosing in spatially fractionated radiation therapy (SFRT) is challenging, and further hampered by the inability of several planning systems to incorporate complex SFRT dose patterns. We developed dosing reference tables for an inventory of tumour scenarios and tested their accuracy with water phantom measurements of GRID therapy, delivered by a standard commercial GRID collimator. We find that dose heterogeneity parameters and EUD modeling are consistent across tumour sizes, configurations, and treatment depths. These results suggest that the developed reference tables can be used as a practical clinical resource for clinical decision-making on GRID therapy and to facilitate heterogeneity dose estimates in clinical patients when this commercially available GRID device is used. Abstract Computations of heterogeneity dose parameters in GRID therapy remain challenging in many treatment planning systems (TPS). To address this difficulty, we developed reference dose tables for a standard GRID collimator and validate their accuracy. The .decimal Inc. GRID collimator was implemented within the Eclipse TPS. The accuracy of the dose calculation was confirmed in the commissioning process. Representative sets of simulated ellipsoidal tumours ranging from 6–20 cm in diameter at a 3-cm depth; 16-cm ellipsoidal tumours at 3, 6, and 10 cm in depth were studied. All were treated with 6MV photons to a 20 Gy prescription dose at the tumour center. From these, the GRID therapy dosimetric parameters (previously recommended by the Radiosurgery Society white paper) were derived. Differences in D5 through D95 and EUD between different tumour sizes at the same depth were within 5% of the prescription dose. PVDR from profile measurements at the tumour center differed from D10/D90, but D10/D90 variations for the same tumour depths were within 11%. Three approximation equations were developed for calculating EUDs of different prescription doses for three radiosensitivity levels for 3-cm deep tumours. Dosimetric parameters were consistent and predictable across tumour sizes and depths. Our study results support the use of the developed tables as a reference tool for GRID therapy.
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29
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Smith BR, M S NPN, M S TJG, M S KAP, Hill PM, Yu J, Gutiérrez AN, Md BGA, Hyer DE. The dosimetric enhancement of GRID profiles using an external collimator in pencil beam scanning proton therapy. Med Phys 2022; 49:2684-2698. [PMID: 35120278 PMCID: PMC9007854 DOI: 10.1002/mp.15523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/22/2021] [Accepted: 01/23/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The radiobiological benefits afforded by spatially fractionated (GRID) radiation therapy pairs well with the dosimetric advantages of proton therapy. Inspired by the emergence of energy-layer specific collimators in pencil beam scanning (PBS), this work investigates how the spot spacing and collimation can be optimized to maximize the therapeutic gains of a GRID treatment while demonstrating the integration of a dynamic collimation system (DCS) within a commercial beam line to deliver GRID treatments and experimentally benchmark Monte Carlo calculation methods. METHODS GRID profiles were experimentally benchmarked using a clinical DCS prototype that was mounted to the nozzle of the IBA Dedicated Nozzle system. Integral depth dose (IDD) curves and lateral profiles were measured for uncollimated and GRID-collimated beamlets. A library of collimated GRID dose distributions were simulated by placing beamlets within a specified uniform grid and weighting the beamlets to achieve a volume-averaged tumor cell survival equivalent to an open field delivery. The healthy tissue sparing afforded by the GRID distribution was then estimated across a range of spot spacings and collimation widths, which were later optimized based on the radiosensitivity of the tumor cell line and the nominal spot size of the PBS system. This was accomplished by using validated models of the IBA Universal and Dedicated nozzles. RESULTS Excellent agreement was observed between the measured and simulated profiles. The IDDs matched above 98.7% when analyzed using a 1%/1 mm gamma criteria with some minor deviation observed near the Bragg peak for higher beamlet energies. Lateral profile distributions predicted using Monte Carlo methods agreed well with the measured profiles; a gamma passing rate of 95% or higher was observed for all in-depth profiles examined using a 3%/2 mm criteria. Additional collimation was shown to improve PBS GRID treatments by sharpening the lateral penumbra of the beamlets but creates a tradeoff between enhancing the valley-to-peak ratio of the GRID delivery and the dose-volume effect. The optimal collimation width and spot spacing changed as a function of the tumor cell radiosensitivity, dose, and spot size. In general, a spot spacing below 2.0 cm with a collimation less than 1.0 cm provided a superior dose distribution among the specific cases studied. CONCLUSIONS The ability to customize a GRID dose distribution using different collimation sizes and spot spacings is a useful advantage, especially to maximize the overall therapeutic benefit. In this regard, the capabilities of the DCS, and perhaps alternative dynamic collimators, can be used to enhance GRID treatments. Physical dose models calculated using Monte Carlo methods were experimentally benchmarked in water and were found to accurately predict the respective dose distributions of uncollimated and DCS-collimated GRID profiles. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Blake R Smith
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, 52242 Iowa
| | - Nicholas P Nelson M S
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, 53705
| | | | | | - Patrick M Hill
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, 53792
| | - Jen Yu
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, 8900 N. Kendall Drive, Miami, FL, 33176
| | - Alonso N Gutiérrez
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, 8900 N. Kendall Drive, Miami, FL, 33176
| | - Bryan G Allen Md
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, 52242 Iowa
| | - Daniel E Hyer
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, 52242 Iowa
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30
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Alanizy N, Attalla E, Abdelaal A, Yassen M, Shafaa M. Biological Evaluation of Grid versus 3D Conformal Radiotherapy in Bulky Head and Neck Cancer. J Med Phys 2022; 47:136-140. [PMID: 36212202 PMCID: PMC9542996 DOI: 10.4103/jmp.jmp_141_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/04/2022] Open
Abstract
Grid radiotherapy is one of the treatment techniques applied to treat patients with advanced bulky tumors.
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31
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A Brief Overview of the Preclinical and Clinical Radiobiology of Microbeam Radiotherapy. Clin Oncol (R Coll Radiol) 2021; 33:705-712. [PMID: 34454806 DOI: 10.1016/j.clon.2021.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/27/2021] [Accepted: 08/17/2021] [Indexed: 11/23/2022]
Abstract
Microbeam radiotherapy (MRT) is the delivery of spatially fractionated beams that have the potential to offer significant improvements in the therapeutic ratio due to the delivery of micron-sized high dose and dose rate beams. They build on longstanding clinical experience of GRID radiotherapy and more recently lattice-based approaches. Here we briefly overview the preclinical evidence for MRT efficacy and highlight the challenges for bringing this to clinical utility. The biological mechanisms underpinning MRT efficacy are still unclear, but involve vascular, bystander, stem cell and potentially immune responses. There is probably significant overlap in the mechanisms underpinning MRT responses and FLASH radiotherapy that needs to be further defined.
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32
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Asperud J, Arous D, Edin NFJ, Malinen E. Spatially fractionated radiotherapy: tumor response modelling including immunomodulation. Phys Med Biol 2021; 66. [PMID: 34298527 DOI: 10.1088/1361-6560/ac176b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/23/2021] [Indexed: 01/20/2023]
Abstract
A mathematical tumor response model has been developed, encompassing the interplay between immune cells and cancer cells initiated by either partial or full tumor irradiation. The iterative four-compartment model employs the linear-quadratic radiation response theory for four cell types: active and inactive cytotoxic T lymphocytes (immune cells, CD8+T cells in particular), viable cancer cells (undamaged and reparable cells) and doomed cells (irreparably damaged cells). The cell compartment interactions are calculated per day, with total tumor volume (TV) as the main quantity of interest. The model was fitted to previously published data on syngeneic xenografts (67NR breast carcinoma and Lewis lung carcinoma; (Markovskyet al2019Int. J. Radiat. Oncol. Biol. Phys.103697-708)) subjected to single doses of 10 or 15 Gy by 50% (partial) or 100% (full) TV irradiation. The experimental data included effects from anti-CD8+antibodies and immunosuppressive drugs. Using a new optimization method, promising fits were obtained where the lowest and highest root-mean-squared error values were observed for anti-CD8+treatment and unirradiated control data, respectively, for both cell types. Additionally, predictive capabilities of the model were tested by using the estimated model parameters to predict scenarios for higher doses and different TV irradiation fractions. Here, mean relative deviations in the range of 19%-34% from experimental data were found. However, more validation data is needed to conclude on the model's predictive capabilities. In conclusion, the model was found useful in evaluating the impact from partial and full TV irradiation on the immune response and subsequent tumor growth. The model shows potential to support and guide spatially fractionated radiotherapy in future pre-clinical and clinical studies.
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Affiliation(s)
- Jonas Asperud
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo, Norway
| | - Delmon Arous
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo, Norway.,Department of Medical Physics, The Norwegian Radium Hospital, Oslo University Hospital, PO Box 4953 Nydalen, N-0424 Oslo, Norway
| | | | - Eirik Malinen
- Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo, Norway.,Department of Medical Physics, The Norwegian Radium Hospital, Oslo University Hospital, PO Box 4953 Nydalen, N-0424 Oslo, Norway
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33
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The role of the spatially fractionated radiation therapy in the management of advanced bulky tumors. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2021. [DOI: 10.2478/pjmpe-2021-0015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract
Spatially fractionated radiation therapy (SFRT) refers to the delivery of a single large dose of radiation within the target volume in a heterogeneous pattern using either a custom GRID block, multileaf collimators, and virtual methods such as helical tomotherapy or synchrotron-based microbeams. The potential impact of this technique on the regression of bulky deep-seated tumors that do not respond well to conventional radiotherapy has been remarkable. To date, a large number of patients have been treated using the SFRT techniques. However, there are yet many technical and medical challenges that have limited their routine use to a handful of clinics, most commonly for palliative intent. There is also a poor understanding of the biological mechanisms underlying the clinical efficacy of this approach. In this article, the methods of SFRT delivery together with its potential biological mechanisms are presented. Furthermore, technical challenges and clinical achievements along with the radiobiological models used to evaluate the efficacy and safety of SFRT are highlighted.
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34
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Snider JW, Molitoris J, Shyu S, Diwanji T, Rice S, Kowalski E, Decesaris C, Remick JS, Yi B, Zhang B, Hall A, Hanna N, Ng VY, Regine WF. Spatially Fractionated Radiotherapy (GRID) Prior to Standard Neoadjuvant Conventionally Fractionated Radiotherapy for Bulky, High-Risk Soft Tissue and Osteosarcomas: Feasibility, Safety, and Promising Pathologic Response Rates. Radiat Res 2021; 194:707-714. [PMID: 33064802 DOI: 10.1667/rade-20-00100.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 09/10/2020] [Indexed: 11/03/2022]
Abstract
Spatially fractionated radiotherapy (GRID) has been utilized primarily in the palliative and definitive treatment of bulky tumors. Delivered in the modern era primarily with megavoltage photon therapy, this technique offers the promise of safe dose escalation with potential immunogenic, bystander and microvasculature effects that can augment a conventionally fractionated course of radiotherapy. At the University of Maryland, an institutional standard has arisen to incorporate a single fraction of GRID radiation in large (>8 cm), high-risk soft tissue and osteosarcomas prior to a standard fractionated course. Herein, we report on the excellent pathologic responses and apparent safety of this regimen in 26 consecutive patients.
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Affiliation(s)
- James W Snider
- University of Alabama at Birmingham School of Medicine, Birmingham, Alabama
| | - Jason Molitoris
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Susan Shyu
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Tejan Diwanji
- University of Miami School of Medicine, Miami, Florida
| | | | - Emily Kowalski
- University of Maryland School of Medicine, Baltimore, Maryland
| | | | - Jill S Remick
- University of Maryland Medical Center, Baltimore, Maryland
| | - Byongyong Yi
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Baoshe Zhang
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea Hall
- University of Maryland Medical Center, Baltimore, Maryland
| | - Nader Hanna
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Vincent Y Ng
- University of Maryland School of Medicine, Baltimore, Maryland
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35
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Amendola BE, Perez NC, Mayr NA, Wu X, Amendola M. Spatially Fractionated Radiation Therapy Using Lattice Radiation in Far-advanced Bulky Cervical Cancer: A Clinical and Molecular Imaging and Outcome Study. Radiat Res 2021; 194:724-736. [PMID: 32853384 DOI: 10.1667/rade-20-00038.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/07/2020] [Indexed: 11/03/2022]
Abstract
Spatially fractionated radiation therapy (SFRT) has shown promise in generating high tumor response and local control in the treatment of various palliative and locally advanced bulky tumors. SFRT has not yet been studied systematically in cancer of the cervix. Here we report the first series of patients receiving SFRT for advanced/bulky cervical cancer. Ten patients with far-advanced bulky cervical cancer, stage IIIB-IVA (seven squamous cell and three adeno/adenosquamous carcinomas) received lattice radiation therapy (LRT), a variant of SFRT. The LRT regimen consisted of a dose of 24 Gy in three fractions, given to an average of five high-dose spheres within the gross tumor volume (GTV). The dose in the peripheral GTV was limited to 9 Gy in three fractions, using the volumetric modulated arc therapy (VMAT) technique. LRT was followed subsequently by conventionally fractionated external beam irradiation to 44.28 Gy (range: 39.60-45.00 Gy in 1.8 Gy fractions). All patients received concurrent cisplatin chemotherapy. Tumor response was assessed clinically, by morphological imaging (CT, MRI) and 18FDG PET/CT. Tumor control and survival rates were estimated using Kaplan-Meier analysis. All patients had local control at a median follow-up of 16 months (1-77). The two-year disease-specific survival rate was 53.3%. All cancer deaths were due to metastatic failure with local control maintained. Among the three patients who died of disease, all had adeno- or adenosquamous carcinoma histology, and no deaths from disease occurred among the patients with squamous cell carcinoma (P = 0.010). There were no grade ≥3 short-term or long-term treatment-related complications. Intra-treatment morphological tumor regression was highly variable (mean: 54%, range: 6-91%). After therapy, the complete metabolic response was 88.9% (8/9), and one patient out of the nine patients with post-treatment PET-CT had partial response (11.1%). Our preliminary data suggest that LRT-based SFRT is well tolerated in patients with far-advanced bulky cervical cancer and results in favorable tumor responses and high local control. These observations confirm prior reports of favorable tumor control and toxicity outcomes with SFRT in other advanced/bulky malignancies. Our findings are corroborated by high molecular-imaging-based tumor response. These encouraging hypothesis-generating results require cautious interpretation and confirmation with larger patient cohorts, preferably through a multi-institutional controlled randomized clinical trial.
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Affiliation(s)
| | | | - Nina A Mayr
- Department of Radiation Oncology, University of Washington School of Medline, Seattle, Washington
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36
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Wu X, Perez NC, Zheng Y, Li X, Jiang L, Amendola BE, Xu B, Mayr NA, Lu JJ, Hatoum GF, Zhang H, Chang SX, Griffin RJ, Guha C. The Technical and Clinical Implementation of LATTICE Radiation Therapy (LRT). Radiat Res 2021; 194:737-746. [PMID: 33064814 DOI: 10.1667/rade-20-00066.1] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 08/24/2020] [Indexed: 11/03/2022]
Abstract
The concept of spatially fractionated radiation therapy (SFRT) was conceived over 100 years ago, first in the form of GRID, which has been applied to clinical practice since its early inception and continued to the present even with markedly improved instrumentation in radiation therapy. LATTICE radiation therapy (LRT) was introduced in 2010 as a conceptual 3D extension of GRID therapy with several uniquely different features. Since 2014, when the first patient was treated, over 150 patients with bulky tumors worldwide have received LRT. Through a brief review of the basic principles and the analysis of the collective clinical experience, a set of technical recommendations and guidelines are proposed for the clinical implementation of LRT. It is to be recognized that the current clinical practice of SFRT (GRID or LRT) is still largely based on the heuristic principles. With advancements in basic biological research and the anticipated clinical trials to systemically assess the efficacy and risk, progressively robust optimizations of the technical parameters are essential for the broader application of SFRT in clinical practice.
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Affiliation(s)
- Xiaodong Wu
- Executive Medical Physics Associates, North Miami Beach, Florida.,Innovative Cancer Institute, South Miami, Florida.,Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.,Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China
| | | | - Yi Zheng
- Executive Medical Physics Associates, North Miami Beach, Florida.,Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China
| | - Xiaobo Li
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China
| | - Liuqing Jiang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China
| | | | - Benhua Xu
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China
| | - Nina A Mayr
- Department of Radiation Oncology, University of Washington School of Medline, Seattle, Washington
| | - Jiade J Lu
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | | | - Hualin Zhang
- Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Sha X Chang
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Chandan Guha
- Department of Radiation Oncology Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York
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37
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Zhang H, Wu X, Zhang X, Chang SX, Megooni A, Donnelly ED, Ahmed MM, Griffin RJ, Welsh JS, Simone CB, Mayr NA. Photon GRID Radiation Therapy: A Physics and Dosimetry White Paper from the Radiosurgery Society (RSS) GRID/LATTICE, Microbeam and FLASH Radiotherapy Working Group. Radiat Res 2021; 194:665-677. [PMID: 33348375 DOI: 10.1667/rade-20-00047.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/18/2020] [Indexed: 11/03/2022]
Abstract
The limits of radiation tolerance, which often deter the use of large doses, have been a major challenge to the treatment of bulky primary and metastatic cancers. A novel technique using spatial modulation of megavoltage therapy beams, commonly referred to as spatially fractionated radiation therapy (SFRT) (e.g., GRID radiation therapy), which purposefully maintains a high degree of dose heterogeneity across the treated tumor volume, has shown promise in clinical studies as a method to improve treatment response of advanced, bulky tumors. Compared to conventional uniform-dose radiotherapy, the complexities of megavoltage GRID therapy include its highly heterogeneous dose distribution, very high prescription doses, and the overall lack of experience among physicists and clinicians. Since only a few centers have used GRID radiation therapy in the clinic, wide and effective use of this technique has been hindered. To date, the mechanisms underlying the observed high tumor response and low toxicity are still not well understood. To advance SFRT technology and planning, the Physics Working Group of the Radiosurgery Society (RSS) GRID/Lattice, Microbeam and Flash Radiotherapy Working Groups, was established after an RSS-NCI Workshop. One of the goals of the Physics Working Group was to develop consensus recommendations to standardize dose prescription, treatment planning approach, response modeling and dose reporting in GRID therapy. The objective of this report is to present the results of the Physics Working Group's consensus that includes recommendations on GRID therapy as an SFRT technology, field dosimetric properties, techniques for generating GRID fields, the GRID therapy planning methods, documentation metrics and clinical practice recommendations. Such understanding is essential for clinical patient care, effective comparisons of outcome results, and for the design of rigorous clinical trials in the area of SFRT. The results of well-conducted GRID radiation therapy studies have the potential to advance the clinical management of bulky and advanced tumors by providing improved treatment response, and to further develop our current radiobiology models and parameters of radiation therapy design.
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Affiliation(s)
- Hualin Zhang
- Department of Radiation Oncology, Northwestern Memorial Hospital, Chicago, Illinois 60611
| | - Xiaodong Wu
- Excecutive Medical Physics Associates and Biophysics Research Institute of America, Miami, Florida 33179
| | - Xin Zhang
- Department of Radiation Oncology, Boston Medical Center, Boston, Massachusetts 02118
| | - Sha X Chang
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27516
| | - Ali Megooni
- Department of Radiation Therapy, Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 86169
| | - Eric D Donnelly
- Department of Radiation Oncology, Northwestern Memorial Hospital, Chicago, Illinois 60611
| | - Mansoor M Ahmed
- Division of Cancer Treatment and Diagnosis, Rockville, Maryland 20892
| | - Robert J Griffin
- University of Arkansas for Medical Sciences, Department of Radiation Oncology, Little Rock, Arkansas
| | - James S Welsh
- Loyola University Chicago, Edward Hines Jr. VA Hospital, Stritch School of Medicine, Department of Radiation Oncology, Maywood, Illinois 60153
| | - Charles B Simone
- New York Proton Center, Department of Radiation Oncology, New York, New York 10035
| | - Nina A Mayr
- Department of Radiation Oncology, University of Washington Medical Center, Seattle, Washington 98195
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38
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Sammer M, Girst S, Dollinger G. Optimizing proton minibeam radiotherapy by interlacing and heterogeneous tumor dose on the basis of calculated clonogenic cell survival. Sci Rep 2021; 11:3533. [PMID: 33574390 PMCID: PMC7878903 DOI: 10.1038/s41598-021-81708-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 12/23/2020] [Indexed: 01/30/2023] Open
Abstract
Proton minibeam radiotherapy (pMBRT) is a spatial fractionation method using sub-millimeter beams at center-to-center (ctc) distances of a few millimeters to widen the therapeutic index by reduction of side effects in normal tissues. Interlaced minibeams from two opposing or four orthogonal directions are calculated to minimize side effects. In particular, heterogeneous dose distributions applied to the tumor are investigated to evaluate optimized sparing capabilities of normal tissues at the close tumor surrounding. A 5 cm thick tumor is considered at 10 cm depth within a 25 cm thick water phantom. Pencil and planar minibeams are interlaced from two (opposing) directions as well as planar beams from four directions. An initial beam size of σ0 = 0.2 mm (standard deviation) is assumed in all cases. Tissue sparing potential is evaluated by calculating mean clonogenic cell survival using a linear-quadratic model on the calculated dose distributions. Interlacing proton minibeams for homogeneous irradiation of the tumor has only minor benefits for the mean clonogenic cell survival compared to unidirectional minibeam irradiation modes. Enhanced mean cell survival, however, is obtained when a heterogeneous dose distribution within the tumor is permitted. The benefits hold true even for an elevated mean tumor dose, which is necessary to avoid cold spots within the tumor in concerns of a prescribed dose. The heterogeneous irradiation of the tumor allows for larger ctc distances. Thus, a high mean cell survival of up to 47% is maintained even close to the tumor edges for single fraction doses in the tumor of at least 10 Gy. Similar benefits would result for heavy ion minibeams with the advantage of smaller minibeams in deep tissue potentially offering even increased tissue sparing. The enhanced mean clonogenic cell survival through large ctc distances for interlaced pMBRT with heterogeneous tumor dose distribution results in optimum tissue sparing potential. The calculations show the largest enhancement of the mean cell survival in normal tissue for high-dose fractions. Thus, hypo-fractionation or even single dose fractions become possible for tumor irradiation. A widened therapeutic index at big cost reductions is offered by interlaced proton or heavy ion minibeam therapy.
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Affiliation(s)
- Matthias Sammer
- Institut für Angewandte Physik und Messtechnik (LRT2), Universität der Bundeswehr München, 85579, Neubiberg, Germany.
| | - Stefanie Girst
- Institut für Angewandte Physik und Messtechnik (LRT2), Universität der Bundeswehr München, 85579, Neubiberg, Germany
| | - Günther Dollinger
- Institut für Angewandte Physik und Messtechnik (LRT2), Universität der Bundeswehr München, 85579, Neubiberg, Germany
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39
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Leat CJ, Ramachandran P, Langton CM. Tungsten carbide and LMPA electron cutouts: comparison and validation using Monte Carlo modelling and measurement of dose. Biomed Phys Eng Express 2020; 7. [PMID: 35093939 DOI: 10.1088/2057-1976/abcb13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 11/17/2020] [Indexed: 11/11/2022]
Abstract
Electron applicator cutouts for radiation therapy electron beam shaping are typically cast from Low Melting Point Alloys (LMPA), such as cerrobend. In this work, we describe the Monte Carlo modelling of novel 3D printed cutouts based on tungsten carbide powder and the resulting dose profiles subject to Elekta Agility electron beams. Cerrobend cutouts were also modelled using the Monte Carlo code EGSnrc. Cerrobend and tungsten carbide cutouts were found to have the same dose profiles within model variance. Computed profiles and percentage depth dose (PDDs) curves of the Elekta Agility accelerator model using standard cutouts in water were found to agree with water tank measurements using gamma criteria of 2%/2mm. The Monte Carlo computed dose profiles of the tungsten carbide cutouts in a polystyrene phantom were also found to agree with liquid-filled ionization chamber array measurements using gamma criteria of 2%/2mm. We conclude that the tungsten carbide cutouts are clinically equivalent to LMPA cutouts.
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Affiliation(s)
| | - Prabhakar Ramachandran
- Radiation Oncology, Princess Alexandra Hospital, Brisbane, Australia.,Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia
| | - Christian M Langton
- Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.,3Done Australia Pty Ltd, Brisbane, Australia
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40
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Murphy NL, Philip R, Wozniak M, Lee BH, Donnelly ED, Zhang H. A simple dosimetric approach to spatially fractionated GRID radiation therapy using the multileaf collimator for treatment of breast cancers in the prone position. J Appl Clin Med Phys 2020; 21:105-114. [PMID: 33119939 PMCID: PMC7700924 DOI: 10.1002/acm2.13040] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 01/06/2023] Open
Abstract
The purpose of this study was to explore the treatment planning methods of spatially fractionated radiation therapy (SFRT), commonly referred to as GRID therapy, in the treatment of breast cancer patients using multileaf collimator (MLC) in the prone position. A total of 12 patients with either left or right breast cancer were retrospectively chosen. The computed tomography (CT) images taken for the whole breast external beam radiation therapy (WB‐EBRT) were used for GRID therapy planning. Each GRID plan was made by using two portals and each portal had two fields with 1‐cm aperture size. The dose prescription point was placed at the center of the target volume, and a dose of 20 Gy with 6‐MV beams was prescribed. Dose‐volume histogram (DVH) curves were generated to evaluate dosimetric properties. A modified linear‐quadratic (MLQ) radiobiological response model was used to assess the equivalent uniform doses (EUD) and therapeutic ratios (TRs) of all GRID plans. The DVH curves indicated that these MLC‐based GRID therapy plans can deliver heterogeneous dose distribution in the target volume as seen with the conventional cerrobend GRID block. The plans generated by the MLC technique also demonstrated the advantage for accommodating different target shapes, sparing normal structures, and reporting dose metrics to the targets and the organs at risks. All GRID plans showed to have similar dosimetric parameters, implying the plans can be made in a consistent quality regardless of the shape of the target and the size of volume. The mean dose of lung and heart were respectively below 0.6 and 0.7 Gy. When the size of aperture is increased from 1 to 2 cm, the EUD and TR became smaller, but the peak/valley dose ratio (PVDR) became greater. The dosimetric approach of this study was proven to be simple, practical and easy to be implemented in clinic.
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Affiliation(s)
- Natasha L Murphy
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Rino Philip
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Matt Wozniak
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Brian H Lee
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Eric D Donnelly
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Hualin Zhang
- Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
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41
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Pakniyat F, Nedaie HA, Mozdarani H, Mahmoudzadeh A, Salimi M, Griffin RJ, Gholami S. Enhanced response of radioresistant carcinoma cell line to heterogeneous dose distribution of grid; the role of high-dose bystander effect. Int J Radiat Biol 2020; 96:1585-1596. [PMID: 33074047 DOI: 10.1080/09553002.2020.1834163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE The classical dogma that restricted the radiation effect to the directly irradiated cells has been challenged by the bystander effect. This off-target phenomenon which was manifested in adjacent cells via signaling of fully exposed cells might be involved in high-dose Grid therapy as well. Here, an in-vitro study was performed to examine the possible extent of carcinoma cells response to the inhomogeneous dose distribution of Grid irradiation in the context of the bystander effect. MATERIALS AND METHODS Bystander effect was investigated in human carcinoma cell lines of HeLa and HN5 adjacent to those received high-dose Grid irradiation using 'medium transfer' and 'cell-to-cell contact' strategies. Based on the Grid peak-to-valley dose profile, medium transfer was exerted from 10 Gy uniformly exposed donors to 1.5 Gy uniformly irradiated recipients. Cell-contact bystander was evaluated after nonuniform dose distribution of 10 Gy Grid irradiation using cloning cylinders. GammaH2AX foci, micronucleus and clonogenic assays besides gene expression analysis were performed. RESULTS Various parameters (ɑ/β, D37, D50) extracted from survival curve which fitted to the Linear Quadratic model, verified more radioresistance of HN5. Survival fraction at 2 Gy (SF2) indicated as 0.42 ± 0.06 in HeLa and 0.5 ± 0.03 in HN5. The level of survival decrease, DNA damages and micronucleus of cells located in the Grid shielded areas (1.5 Gy cell-to-cell contact bystander cells) were significantly more than the values obtained from cells which were irradiated by merely uniform dose of 1.5 Gy. The gH2AX foci and micronuclei frequencies were enhanced in cell-contact bystander approximately more than 1.8 times. Relative expression of DNA damage repair pathway genes (Xrcc6 and H2afx) in bystander cells increased significantly. The most cell survival reduction (11.6 times) was revealed in the Grid bystander cells of radioresistant cell line (HN5). No statistically significant difference between 10 Gy uniform beam and Grid non-uniform beam was observed. CONCLUSIONS Various endpoints confirmed an augmented response of cells in the valley dose region of the Grid block significantly (compared with the cells irradiated by identical dose of uniform beam), suggesting the role of high-dose bystander effect which was more pronounced in resistant carcinoma cell lines. These findings could provide a partial explanation for the Grid beneficial response seen in a number of pre-clinical and clinical studies.
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Affiliation(s)
- Fatemeh Pakniyat
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Ali Nedaie
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Radiation Oncology Research Center, Cancer institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Aziz Mahmoudzadeh
- Department of Bioscience and Biotechnology, Malek-Ashtar University of Technology, Tehran, Iran
| | - Mahdieh Salimi
- Department of Medical genetics, Medical Biotechnology Institute, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Somayeh Gholami
- Radiation Oncology Research Center, Cancer institute, Tehran University of Medical Sciences, Tehran, Iran
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Yan H, Sun W, Mruthyunjaya P, Beadle B, Yu W, Kanwal B, MacDonald CA, Liu W. Dosimetry modeling of focused kV x‐ray radiotherapy for wet age‐related macular degeneration. Med Phys 2020; 47:5123-5134. [DOI: 10.1002/mp.14404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/22/2020] [Accepted: 07/07/2020] [Indexed: 11/12/2022] Open
Affiliation(s)
- Huagang Yan
- School of Biomedical Engineering Capital Medical University Beijing100069 China
| | - Weiyuan Sun
- Department of Physics University at AlbanySUNY Albany NY12222 USA
| | - Prithvi Mruthyunjaya
- Department of Ophthalmology Stanford University School of Medicine Stanford CA94305 USA
| | - Beth Beadle
- Department of Radiation Oncology Stanford University School of Medicine Stanford CA94305 USA
| | - Weihong Yu
- Department of Ophthalmology Key Laboratory of Ocular Fundus Diseases Peking Union Medical College HospitalChinese Academy of Medical Sciences Beijing100730 China
| | - Bushra Kanwal
- Center for High Energy Physics University of the Punjab Lahore Pakistan
| | | | - Wu Liu
- Department of Radiation Oncology Stanford University School of Medicine Stanford CA94305 USA
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Photon and photon–neutron experimental dosimetry in Grid therapy with 18 MV photon beams. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920000655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractPropose:Spatially fractionated Grid radiation therapy (SFGRT) in an effective technique for bulky and radio-sensitive tumours. SFGRT using a constructed block has been used to evaluate the photon and photo-neutron (PN) dose measurement in 18-MV photon beam energy.Methods and materials:A mounted Grid block on to a Varian Clinac 2100c linear accelerator was used to perform photon dosimetry. The percentage depth dose, in-plane and cross-plane beam profile and output factor was measured by ionization chamber in water. The PN contamination was measured after photon dosimetry using the combination of thermoluminescence dosimetry types 600 and 700, and Polycarbonate Film dosimeters on the surface and in the maximum depth dose (dmax) of solid water™ slabs.Results:The valley-to-peak ration for 6 and 18 MV photon beams obtained from the beam profiles was ~35 and 72%, respectively. Fast and thermal PN equivalent dose decreased in the Grid field compared to an open field (without Grid).Conclusion:The Grid therapy dosimetry compared to the conventional radiotherapy (without the grid) the production of fast and thermal neutrons were reduced. Using of a Grid block in high-energy photon beams for a long period of the treatment continuously might be a new source of contamination due to the interaction of photon beam resulting the activation of the Grid block
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Griffin RJ, Prise KM, McMahon SJ, Zhang X, Penagaricano J, Butterworth KT. History and current perspectives on the biological effects of high-dose spatial fractionation and high dose-rate approaches: GRID, Microbeam & FLASH radiotherapy. Br J Radiol 2020; 93:20200217. [PMID: 32706989 DOI: 10.1259/bjr.20200217] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The effects of various forms of ionising radiation are known to be mediated by interactions with cellular and molecular targets in irradiated and in some cases non-targeted tissue volumes. Despite major advances in advanced conformal delivery techniques, the probability of normal tissue complication (NTCP) remains the major dose-limiting factor in escalating total dose delivered during treatment. Potential strategies that have shown promise as novel delivery methods in achieving effective tumour control whilst sparing organs at risk involve the modulation of critical dose delivery parameters. This has led to the development of techniques using high dose spatial fractionation (GRID) and ultra-high dose rate (FLASH) which have translated to the clinic. The current review discusses the historical development and biological basis of GRID, microbeam and FLASH radiotherapy as advanced delivery modalities that have major potential for widespread implementation in the clinic in future years.
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Affiliation(s)
- Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Kevin M Prise
- Patrick G Johnston Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Stephen J McMahon
- Patrick G Johnston Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Xin Zhang
- Department of Radiation Oncology, Boston University Medical Centre, Boston, MA, USA
| | - Jose Penagaricano
- Department of Radiation Oncology, Moffitt Cancer Centre, Tampa, FL, USA
| | - Karl T Butterworth
- Patrick G Johnston Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
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45
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Kopchick B, Xu H, Niu Y, Becker S, Qiu X, Yu C. Technical Note: Dosimetric feasibility of lattice radiotherapy for breast cancer using GammaPod. Med Phys 2020; 47:3928-3934. [PMID: 32640039 DOI: 10.1002/mp.14379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/06/2020] [Accepted: 06/10/2020] [Indexed: 01/16/2023] Open
Abstract
PURPOSE Studies on Lattice radiotherapy (LRT) for breast cancer have been largely lacking. This study investigates the dosimetric feasibility of using Gamma Pod, a stereotactic radiotherapy apparatus originally designed for breast SBRT, to deliver LRT to large, bulky breast tumor as a noninvasive treatment option. METHODS The GammaPod-based LRT was simulated using Geant4 Gate Monte Carlo software. The simulated GammaPod was equipped with 5 mm diameter non-coplanar circular beams that span 28° latitudinally from 18° to 43° off the horizontal plane. Two degrees longitudinal intervals were used to simulate rotating sources. To simulate the treatments to different breast sizes, three water-equivalent hemisphere volumes with diameters of 10, 15, and 20 cm were analyzed. The lattice was planned by spacing focal points 2 cm apart in the transverse and sagittal planes and 2.5 cm in the coronal plane. This resulted in 22-172 shots for full breast treatment. The maximum dose for each individual shot was 20 Gy. The peak-to-valley dose differences and skin dose were analyzed. To verify the feasibility of delivering LRT, a test plan was created and delivered to a commercial diode array dose verification device using a clinical GammaPod system with 15 mm collimators. RESULTS The dose profiles showed the average peak-to-valley dose percent differences of 94.10% in the 10 cm hemispherical volume, 88.95% in the 15 cm hemispherical volume, and 83.60% in the 20 cm hemispherical volume. Average skin dose was 1.27, 1.72, and 2.13 Gy for the 10, 15, and 20 cm irradiation volumes, respectively. The LRT plan delivered using a clinical GammaPod system with larger collimators verified the feasibility of LRT plan delivery. CONCLUSION GammaPod-based lattice radiotherapy is a viable treatment option and its application can be extended to treating large bulky breast tumors.
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Affiliation(s)
| | - Huijun Xu
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Ying Niu
- Xcision Medical Systems, Columbia, MD, 21045, USA
| | - Stewart Becker
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Xiangyun Qiu
- The George Washington University, Washington, DC, 20052, USA
| | - Cedric Yu
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Xcision Medical Systems, Columbia, MD, 21045, USA
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46
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Conventional dose rate spatially-fractionated radiation therapy (SFRT) treatment response and its association with dosimetric parameters-A preclinical study in a Fischer 344 rat model. PLoS One 2020; 15:e0229053. [PMID: 32569277 PMCID: PMC7307781 DOI: 10.1371/journal.pone.0229053] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/21/2020] [Indexed: 12/15/2022] Open
Abstract
Purpose To identify key dosimetric parameters that have close associations with tumor treatment response and body weight change in SFRT treatments with a large range of spatial-fractionation scale at dose rates of several Gy/min. Methods Six study arms using uniform tumor radiation, half-tumor radiation, 2mm beam array radiation, 0.3mm minibeam radiation, and an untreated arm were used. All treatments were delivered on a 320kV x-ray irradiator. Forty-two female Fischer 344 rats with fibrosarcoma tumor allografts were used. Dosimetric parameters studied are peak dose and width, valley dose and width, peak-to-valley-dose-ratio (PVDR), volumetric average dose, percentage volume directly irradiated, and tumor- and normal-tissue EUD. Animal survival, tumor volume change, and body weight change (indicative of treatment toxicity) are tested for association with the dosimetric parameters using linear regression and Cox Proportional Hazards models. Results The dosimetric parameters most closely associated with tumor response are tumor EUD (R2 = 0.7923, F-stat = 15.26*; z-test = -4.07***), valley (minimum) dose (R2 = 0.7636, F-stat = 12.92*; z-test = -4.338***), and percentage tumor directly irradiated (R2 = 0.7153, F-stat = 10.05*; z-test = -3.837***) per the linear regression and Cox Proportional Hazards models, respectively. Tumor response is linearly proportional to valley (minimum) doses and tumor EUD. Average dose (R2 = 0.2745, F-stat = 1.514 (no sig.); z-test = -2.811**) and peak dose (R2 = 0.04472, F-stat = 0.6874 (not sig.); z-test = -0.786 (not sig.)) show the weakest associations to tumor response. Only the uniform radiation arm did not gain body weight post-radiation, indicative of treatment toxicity; however, body weight change in general shows weak association with all dosimetric parameters except for valley (minimum) dose (R2 = 0.3814, F-stat = 13.56**), valley width (R2 = 0.2853, F-stat = 8.783**), and peak width (R2 = 0.2759, F-stat = 8.382**). Conclusions For a single-fraction SFRT at conventional dose rates, valley, not peak, dose is closely associated with tumor treatment response and thus should be used for treatment prescription. Tumor EUD, valley (minimum) dose, and percentage tumor directly irradiated are the top three dosimetric parameters that exhibited close associations with tumor response.
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47
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Mazal A, Prezado Y, Ares C, de Marzi L, Patriarca A, Miralbell R, Favaudon V. FLASH and minibeams in radiation therapy: the effect of microstructures on time and space and their potential application to protontherapy. Br J Radiol 2020; 93:20190807. [PMID: 32003574 PMCID: PMC7066940 DOI: 10.1259/bjr.20190807] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
After years of lethargy, studies on two non-conventional microstructures in time and space of the beams used in radiation therapy are enjoying a huge revival. The first effect called “FLASH” is based on very high dose-rate irradiation (pulse amplitude ≥106 Gy/s), short beam-on times (≤100 ms) and large single doses (≥10 Gy) as experimental parameters established so far to give biological and potential clinical effects. The second effect relies on the use of arrays of minibeams (e.g., 0.5–1 mm, spaced 1–3.5 mm). Both approaches have been shown to protect healthy tissues as an endpoint that must be clearly specified and could be combined with each other (e.g., minibeams under FLASH conditions). FLASH depends on the presence of oxygen and could proceed from the chemistry of peroxyradicals and a reduced incidence on DNA and membrane damage. Minibeams action could be based on abscopal effects, cell signalling and/or migration of cells between “valleys and hills” present in the non-uniform irradiation field as well as faster repair of vascular damage. Both effects are expected to maintain intact the tumour control probability and might even preserve antitumoural immunological reactions. FLASH in vivo experiments involving Zebrafish, mice, pig and cats have been done with electron beams, while minibeams are an intermediate approach between X-GRID and synchrotron X-ray microbeams radiation. Both have an excellent rationale to converge and be applied with proton beams, combining focusing properties and high dose rates in the beam path of pencil beams, and the inherent advantage of a controlled limited range. A first treatment with electron FLASH (cutaneous lymphoma) has recently been achieved, but clinical trials have neither been presented for FLASH with protons, nor under the minibeam conditions. Better understanding of physical, chemical and biological mechanisms of both effects is essential to optimize the technical developments and devise clinical trials.
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Affiliation(s)
| | - Yolanda Prezado
- IMNC, University Paris-Sud and Paris-Saclay, CNRS/IN2P3, Orsay, France
| | - Carme Ares
- Centro de Protonterapia Quironsalud, Madrid, Spain
| | - Ludovic de Marzi
- Institut Curie, Institut Curie, PSL Research University, Centre de protonthérapie d'Orsay, Campus universitaire, bâtiment 101, Orsay 91898, France.,Institut Curie, Inserm U 1021-CNRS UMR 3347, Paris-Saclay and PSL Research Universities, Orsay, France
| | - Annalisa Patriarca
- Institut Curie, Institut Curie, PSL Research University, Centre de protonthérapie d'Orsay, Campus universitaire, bâtiment 101, Orsay 91898, France
| | | | - Vincent Favaudon
- Institut Curie, Inserm U 1021-CNRS UMR 3347, Paris-Saclay and PSL Research Universities, Orsay, France
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Pokhrel D, Halfman M, Sanford L, Chen Q, Kudrimoti M. A novel, yet simple MLC-based 3D-crossfire technique for spatially fractionated GRID therapy treatment of deep-seated bulky tumors. J Appl Clin Med Phys 2020; 21:68-74. [PMID: 32034989 PMCID: PMC7075376 DOI: 10.1002/acm2.12826] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/11/2019] [Accepted: 01/08/2020] [Indexed: 11/12/2022] Open
Abstract
Purpose Treating deep‐seated bulky tumors with traditional single‐field Cerrobend GRID‐blocks has many limitations such as suboptimal target coverage and excessive skin toxicity. Heavy traditional GRID‐blocks are a concern for patient safety at various gantry‐angles and dosimetric detail is not always available without a GRID template in user’s treatment planning system. Herein, we propose a simple, yet clinically useful multileaf collimator (MLC)‐based three‐dimensional (3D)‐crossfire technique to provide sufficient target coverage, reduce skin dose, and potentially escalate tumor dose to deep‐seated bulky tumors. Materials/methods Thirteen patients (multiple sites) who underwent conventional single‐field cerrobend GRID‐block therapy (maximum, 15 Gy in 1 fraction) were re‐planned using an MLC‐based 3D‐crossfire method. Gross tumor volume (GTV) was used to generate a lattice pattern of 10 mm diameter and 20 mm center‐to‐center mimicking conventional GRID‐block using an in‐house MATLAB program. For the same prescription, MLC‐based 3D‐crossfire grid plans were generated using 6‐gantry positions (clockwise) at 60° spacing (210°, 270°, 330°, 30°, 90°, 150°, therefore, each gantry angle associated with a complement angle at 180° apart) with differentially‐weighted 6 or 18 MV beams in Eclipse. For each gantry, standard Millenium120 (Varian) 5 mm MLC leaves were fit to the grid‐pattern with 90° collimator rotation, so that the tunneling dose distribution was achieved. Acuros‐based dose was calculated for heterogeneity corrections. Dosimetric parameters evaluated include: mean GTV dose, GTV dose heterogeneities (peak‐to‐valley dose ratio, PVDR), skin dose and dose to other adjacent critical structures. Additionally, planning time and delivery efficiency was recorded. With 3D‐MLC, dose escalation up to 23 Gy was simulated for all patient's plans. Results All 3D‐MLC crossfire GRID plans exhibited excellent target coverage with mean GTV dose of 13.4 ± 0.5 Gy (range: 12.43–14.24 Gy) and mean PVDR of 2.0 ± 0.3 (range: 1.7–2.4). Maximal and dose to 5 cc of skin were 9.7 ± 2.7 Gy (range: 5.4–14.0 Gy) and 6.3 ± 1.8 Gy (range: 4.1–11.1 Gy), on average respectively. Three‐dimensional‐MLC treatment planning time was about an hour or less. Compared to traditional GRID‐block, average beam on time was 20% less, while providing similar overall treatment time. With 3D‐MLC plans, tumor dose can be escalated up to 23 Gy while respecting skin dose tolerances. Conclusion The simple MLC‐based 3D‐crossfire GRID‐therapy technique resulted in enhanced target coverage for de‐bulking deep‐seated bulky tumors, reduced skin toxicity and spare adjacent critical structures. This simple MLC‐based approach can be easily adopted by any radiotherapy center. It provides detailed dosimetry and a safe and effective treatment by eliminating the heavy physical GRID‐block and could potentially provide same day treatment. Prospective clinical trial with higher tumor‐dose to bulky deep‐seated tumors is anticipated.
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Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Matthew Halfman
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Lana Sanford
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Quan Chen
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Mahesh Kudrimoti
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
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Yan W, Khan MK, Wu X, Simone CB, Fan J, Gressen E, Zhang X, Limoli CL, Bahig H, Tubin S, Mourad WF. Spatially fractionated radiation therapy: History, present and the future. Clin Transl Radiat Oncol 2020; 20:30-38. [PMID: 31768424 PMCID: PMC6872856 DOI: 10.1016/j.ctro.2019.10.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Weisi Yan
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mohammad K. Khan
- Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | | | - Charles B. Simone
- New York Proton Center, Department of Radiation Oncology, New York, NY, USA
| | - Jiajin Fan
- Radiation Oncology, Inova Schar Cancer Institute, Inova Health System, USA
| | - Eric Gressen
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Xin Zhang
- Boston University School of Medicine, Boston, MA, USA
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California, Ivine 92697-2695, USA
| | - Houda Bahig
- Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
| | - Slavisa Tubin
- KABEG Klinikum Klagenfurt, Institute of Radiation Oncology, Feschnigstraße 11, 9020 Klagenfurt am Wörthersee, Austria
| | - Waleed F. Mourad
- Department of Radiation Medicine, Markey Cancer Center, University of Kentucky – College of Medicine, USA
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50
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Mohiuddin M, Lynch C, Gao M, Hartsell W. Early clinical results of proton spatially fractionated GRID radiation therapy (SFGRT). Br J Radiol 2019; 93:20190572. [PMID: 31651185 DOI: 10.1259/bjr.20190572] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Approximately 70 patients with large and bulky tumors refractory to prior treatments were treated with photon spatially fractionated GRID radiation (SFGRT). We identified 10 additional patients who clinically needed GRID but could not be treated with photons due to adjacent critical organs. We developed a proton SFGRT technique, and we report treatment of these 10 patients. METHODS Subject data were reviewed for clinical results and dosimetric data. 50% of the patients were metastatic at the time of treatment and five had previous photon radiation to the local site but not via GRID. They were treated with 15-20 cobalt Gray equivalent using a single proton GRID field with an average beamlet count of 22.6 (range 7-51). 80% received an average adjuvant radiation dose to the GRID region of 40.8Gy (range 13.7-63.8Gy). Four received subsequent systemic therapy. RESULTS The median follow-up time was 5.9 months (1.1-18.9). At last follow-up, seven patients were alive and three had died. Two patients who had died from metastatic disease had local shrinkage of tumor. Of those alive, four had complete or partial response, two had partial response but later progressed, and one had no response. For all patients, the tumor regression/local symptom improvement rate was 80%. 50% had acute side-effects of grade1/2 only and all were well-tolerated. CONCLUSION In circumstances where patients cannot receive photon GRID, proton SFGRT is clinically feasible and effective, with a similar side-effect profile. ADVANCES IN KNOWLEDGE Proton GRID should be considered as a treatment option earlier in the disease course for patients who cannot be treated by photon GRID.
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Affiliation(s)
- Majid Mohiuddin
- Northwestern Medicine Chicago Proton Center 4455 Weaver Pkwy, Warrenville, IL 60555.,Radiation Oncology Consultants, Ltd. 700 Commerce Drive, Suite 500, Oak Brook, IL 60523
| | - Connor Lynch
- Northwestern Medicine Chicago Proton Center 4455 Weaver Pkwy, Warrenville, IL 60555
| | - Mingcheng Gao
- Northwestern Medicine Chicago Proton Center 4455 Weaver Pkwy, Warrenville, IL 60555
| | - William Hartsell
- Northwestern Medicine Chicago Proton Center 4455 Weaver Pkwy, Warrenville, IL 60555.,Radiation Oncology Consultants, Ltd. 700 Commerce Drive, Suite 500, Oak Brook, IL 60523
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