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Kuperman VY, Altundal Y, Kandel S, Kouskoulas TN. Dose conformity and falloff in single-lesion intracranial SRS with DCA and VMAT methods. J Appl Clin Med Phys 2024:e14415. [PMID: 38924344 DOI: 10.1002/acm2.14415] [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: 12/28/2023] [Revised: 04/25/2024] [Accepted: 05/06/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Intracranial stereotactic radiosurgery (SRS) aims at achieving highly conformal dose distribution and, at the same time, attaining rapid dose falloff outside the treatment target. SRS is performed using different techniques including dynamic conformal arcs (DCA) and volumetric modulated arc therapy (VMAT). PURPOSE In this study, we compare dose conformity and falloff in DCA and VMAT plans for SRS with a single target. METHODS To compare dose conformity in SRS plans, we employ a novel conformity indexC I d e x p $C{I}_{{d}_{exp}}$ , RTOG conformity index (C I R T O G $C{I}_{RTOG}$ ), and Riet-Paddick conformity index (C I R P $C{I}_{RP}$ ). In addition, we use indicesR 50 % $R50\% $ ,V 10 G y ${V}_{10Gy}$ , andV 12 G y ${V}_{12Gy}$ to evaluate dose falloff. For each of the considered 118 cases of SRS, two plans were created using DCA and VMAT. A two-tailed Student's t-test was used to evaluate the difference between the employed indices for the DCA and VMAT plans. RESULTS The studied VMAT plans were characterized by higher dose conformity than the DCA plans. The differences between the conformity indices for the DCA plans and VMAT plans were statistically significant. The DCA plans had a smaller number of monitor units (MUs) and smaller indices R50%, V10 Gy, and V12 Gy than the VMAT plans. However, the differences between R50%, V10 Gy, and V12 Gy for the DCA and VMAT plans were not statistically significant. CONCLUSIONS Although the studied VMAT plans had higher dose conformity, they also had larger MUs than the DCA plans. In terms of dose falloff characterized by parameters R50%, V10 Gy, and V12 Gy, DCA serves as a reasonable alternative to VMAT in the case of a single brain metastasis.
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Affiliation(s)
- Vadim Y Kuperman
- Florida Cancer Specialists & Research Institute, Hudson, Florida, USA
| | - Yücel Altundal
- Florida Cancer Specialists & Research Institute, Hudson, Florida, USA
| | - Sunil Kandel
- Florida Cancer Specialists & Research Institute, Hudson, Florida, USA
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Faccenda V, Panizza D, Pisoni V, Trivellato S, Daniotti MC, Bianchi SP, De Ponti E, Arcangeli S. Single-Isocenter Linac-Based Radiosurgery for Brain Metastases with Coplanar Arcs: A Dosimetric and Clinical Analysis. Cancers (Basel) 2023; 15:4496. [PMID: 37760466 PMCID: PMC10526167 DOI: 10.3390/cancers15184496] [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: 07/11/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
The efficacy of linac-based SRS/fSRS treatments using the single-isocenter coplanar FFF-VMAT technique for both single and multiple BM was investigated. Seventy patients (129 BM) treated with 15-21 Gy in 1 (n = 59) or 27 Gy in 3 (n = 11) fractions were analyzed. For each fraction, plans involving the intra-fractional errors measured by post-treatment CBCT were recalculated. The relationships of BM size, distance-to-isocenter, and barycenter shift with the difference in target coverage were evaluated. Clinical outcomes were assessed using logistic regression and Kaplan-Meier analysis. The median delivery time was 3.78 min (range, 1.83-9.25). The median post-treatment 3D error was 0.5 mm (range, 0.1-2.7) and the maximum rotational error was 0.3° (range, 0.0-1.3). In single BM patients, the GTV D95% was never reduced by >5%, whereas PTV D95% reductions >1% occurred in only 11 cases (29%). In multiple BM patients, dose deficits >5% and >1% occurred in 2 GTV (2%) and 34 PTV (37%), respectively. The differences in target coverage showed a moderate-to-strong correlation only with barycenter shift. Local failure of at least one treated BM occurred in 13 (21%) patients and the 1-year and 2-year local control rates for all lesions were 94% and 90%, respectively. The implemented workflow ensured that the degradation of target and brain dose metrics in delivered treatments was negligible. Along with encouraging clinical outcomes, these findings warrant a reduction in the PTV margins at our institution.
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Affiliation(s)
- Valeria Faccenda
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Denis Panizza
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Valerio Pisoni
- Radiation Oncology Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy;
| | - Sara Trivellato
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Martina Camilla Daniotti
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Sofia Paola Bianchi
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Elena De Ponti
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Stefano Arcangeli
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
- Radiation Oncology Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy;
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Kuperman VY, Altundal Y. Novel approach for the evaluation of dose conformity in radiotherapy. Med Phys 2023; 50:1086-1095. [PMID: 36272439 DOI: 10.1002/mp.15998] [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: 01/31/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 12/14/2022] Open
Abstract
PURPOSE We describe a new approach to evaluate conformity of dose distributions in radiotherapy. METHODS The suggested conformity factor λ is defined by using existing conformity indices and expansion of the planning target volume (PTV). If the average distance ( d ¯ $\bar d$ ) between the PTV and reference isodose surface and an arbitrarily selected PTV expansion margin ( d e x p ${d_{exp}}$ ) are both much smaller than the size of the PTV, then λ approximately equals the ratio d ¯ d e x p $\frac{{\bar d}}{{{d_{exp}}}}$ . We use λ to analyze several cases of stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT). RESULTS In the case of SRS with a single target or multiple targets, treatment plans produced with the help of volumetric modulated arc therapy (VMAT) have smaller λ than plans produced by using dynamic conformal arcs (DCA). Likewise, it is demonstrated that in the case of SBRT, λ is reduced by employing VMAT instead of DCA. It is also shown that if the distance between the reference isodose surface and surface of the PTV is fixed, λ varies less with variations in PTV volume compared to frequently used conformity indices. CONCLUSIONS The described conformity factor λ can be applied clinically to compare and rank treatment plans for lesions of different sizes. It is suggested that conditions λ < 1 $\lambda < 1$ and λ > 1 can be employed as "pass" and "fail" criteria, respectively, for dose conformity assessment with appropriate choice of d e x p ${d_{exp}}$ .
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Affiliation(s)
- Vadim Y Kuperman
- Florida Cancer Specialists & Research Institute, Hudson, Florida, USA
| | - Yücel Altundal
- Florida Cancer Specialists & Research Institute, Hudson, Florida, USA
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Grishchuk D, Dimitriadis A, Sahgal A, De Salles A, Fariselli L, Kotecha R, Levivier M, Ma L, Pollock BE, Regis J, Sheehan J, Suh J, Yomo S, Paddick I. ISRS Technical Guidelines for Stereotactic Radiosurgery: Treatment of Small Brain Metastases (≤1 cm in Diameter). Pract Radiat Oncol 2022; 13:183-194. [PMID: 36435388 DOI: 10.1016/j.prro.2022.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE The objective of this literature review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus technical guidelines for the treatment of small, ≤1 cm in maximal diameter, intracranial metastases with stereotactic radiosurgery. Although different stereotactic radiosurgery technologies are available, most of them have similar treatment workflows and common technical challenges that are described. METHODS AND MATERIALS A systematic review of the literature published between 2009 and 2020 was performed in Pubmed using the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) methodology. The search terms were limited to those related to radiosurgery of brain metastases and to publications in the English language. RESULTS From 484 collected abstract 37 articles were included into the detailed review and bibliographic analysis. An additional 44 papers were identified as relevant from a search of the references. The 81 papers, including additional 7 international guidelines, were deemed relevant to at least one of five areas that were considered paramount for this report. These areas of technical focus have been employed to structure these guidelines: imaging specifications, target volume delineation and localization practices, use of margins, treatment planning techniques, and patient positioning. CONCLUSION This systematic review has demonstrated that Stereotactic Radiosurgery (SRS) for small (1 cm) brain metastases can be safely performed on both Gamma Knife (GK) and CyberKnife (CK) as well as on modern LINACs, specifically tailored for radiosurgical procedures, However, considerable expertise and resources are required for a program based on the latest evidence for best practice.
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Affiliation(s)
- Diana Grishchuk
- National Hospital for Neurology and Neurosurgery, London, United Kingdom.
| | - Alexis Dimitriadis
- National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
| | - Antonio De Salles
- Department of Neurosurgery, University of California, Los Angeles, California
| | - Laura Fariselli
- Radiotherapy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta Milano, Unita di Radiotherapia, Milan, Italy
| | - Rupesh Kotecha
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida
| | - Marc Levivier
- Neurosurgery Service and Gamma Knife Center, Center Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Lijun Ma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California
| | - Bruce E Pollock
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Jean Regis
- Department of Functional Neurosurgery, La Timone Hospital, Aix-Marseille University, Marseille, France
| | - Jason Sheehan
- Department of Neurologic Surgery, University of Virginia, Charlottesville, Virginia
| | - John Suh
- Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio
| | - Shoji Yomo
- Division of Radiation Oncology, Aizawa Comprehensive Cancer Center, Aizawa Hospital, Matsumoto, Japan
| | - Ian Paddick
- National Hospital for Neurology and Neurosurgery, London, United Kingdom
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Pappas EP, Seimenis I, Kouris P, Theocharis S, Lampropoulos KI, Kollias G, Karaiskos P. Target localization accuracy in frame‐based stereotactic radiosurgery: Comparison between MR‐only and MR/CT co‐registration approaches. J Appl Clin Med Phys 2022; 23:e13580. [PMID: 35285583 PMCID: PMC9121047 DOI: 10.1002/acm2.13580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022] Open
Abstract
Purpose In frame‐based Gamma Knife (GK) stereotactic radiosurgery two treatment planning workflows are commonly employed; one based solely on magnetic resonance (MR) images and the other based on magnetic resonance/computed tomography (MR/CT) co‐registered images. In both workflows, target localization accuracy (TLA) can be deteriorated due to MR‐related geometric distortions and/or MR/CT co‐registration uncertainties. In this study, the overall TLA following both clinical workflows is evaluated for cases of multiple brain metastases. Methods A polymer gel‐filled head phantom, having the Leksell stereotactic headframe attached, was CT‐imaged and irradiated by a GK Perfexion unit. A total of 26 4‐mm shots were delivered at 26 locations directly defined in the Leksell stereotactic space (LSS), inducing adequate contrast in corresponding T2‐weighted (T2w) MR images. Prescribed shot coordinates served as reference locations. An additional MR scan was acquired to implement the “mean image” distortion correction technique. The TLA for each workflow was assessed by comparing the radiation‐induced target locations, identified in MR images, with corresponding reference locations. Using T1w MR and CT images of 15 patients (totaling 81 lesions), TLA in clinical cases was similarly assessed, considering MR‐corrected data as reference. For the MR/CT workflow, both global and region of interest (ROI)‐based MR/CT registration approaches were studied. Results In phantom measurements, the MR‐corrected workflow demonstrated unsurpassed TLA (median offset of 0.2 mm) which deteriorated for MR‐only and MR/CT workflows (median offsets of 0.8 and 0.6 mm, respectively). In real‐patient cases, the MR‐only workflow resulted in offsets that exhibit a significant positive correlation with the distance from the MR isocenter, reaching 1.1 mm (median 0.6 mm). Comparable results were obtained for the MR/CT‐global workflow, although a maximum offset of 1.4 mm was detected. TLA was improved with the MR/CT‐ROI workflow resulting in median/maximum offsets of 0.4 mm/1.1 mm. Conclusions Subpixel TLA is achievable in all workflows. For the MR/CT workflow, a ROI‐based MR/CT co‐registration approach could considerably increase TLA and should be preferred instead of a global registration.
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Affiliation(s)
- Eleftherios P. Pappas
- Medical Physics Laboratory Medical School National and Kapodistrian University of Athens Athens Greece
| | - Ioannis Seimenis
- Medical Physics Laboratory Medical School National and Kapodistrian University of Athens Athens Greece
| | - Panagiotis Kouris
- Medical Physics Laboratory Medical School National and Kapodistrian University of Athens Athens Greece
| | - Stefanos Theocharis
- Medical Physics Laboratory Medical School National and Kapodistrian University of Athens Athens Greece
| | | | - Georgios Kollias
- Medical Physics and Gamma Knife Department Hygeia Hospital Marousi Greece
| | - Pantelis Karaiskos
- Medical Physics Laboratory Medical School National and Kapodistrian University of Athens Athens Greece
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Duggar WN, Morris B, He R, Yang CC. Ramifications of Setup Margin Use During Frameless Stereotactic Radiosurgery/Therapy With Gamma Knife Icon Cone-Beam Computed Tomography (CBCT): A Dosimetric Study. Cureus 2022; 14:e21996. [PMID: 35282559 PMCID: PMC8906882 DOI: 10.7759/cureus.21996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2022] [Indexed: 11/05/2022] Open
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Yusuf M, Rattani A, Gaskins J, Oliver AL, Mandish SF, Burton E, May ME, Williams B, Ding D, Sharma M, Miller D, Woo S. Stereotactic radiosurgery for melanoma brain metastases: dose-size response relationship in the era of immunotherapy. J Neurooncol 2021; 156:163-172. [PMID: 34807342 PMCID: PMC8606626 DOI: 10.1007/s11060-021-03899-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/11/2021] [Indexed: 10/26/2022]
Abstract
PURPOSE/OBJECTIVE(S) To determine, for intact melanoma brain metastases (MBM) treated with single-fraction stereotactic radiosurgery (SRS), whether planning parameter peripheral dose per lesion diameter (PDLDm, Gy/mm) and lesion control (LC) differs with versus without immunotherapy (IO). MATERIALS/METHODS We performed a retrospective analysis of patients with intact MBM treated with SRS from 2008 to 2019. Cox-frailty models were constructed to include confounders selected by penalized Cox regression models with a LASSO selector. Interaction effect testing was used to determine whether a significant effect between IO and PDLDm could be demonstrated with respect to LC. RESULTS The study cohort comprised 67 patients with 244 MBMs treated with SRS (30 patients with 122 lesions treated with both SRS and IO) were included. The logarithm of PDLDm was selected as a predictor of LC (HR 0.307, 95% CI 0.098-0.441), adjusting for IO receipt (HR 0.363, 95% CI 0.108-1.224). Interaction effect testing demonstrated a differential effect of PDLDm by IO receipt, with respect to LC (p = 0.048). Twelve-month LC rates for a 7.5 mm lesion receiving SRS (18 Gy) with IO versus without IO were 87.8% (95% CI 69.0-98.3%) versus 79.8% (95% CI 55.1-93.8%) respectively. CONCLUSION PDLDm predicted LC in patients with small MBMs treated with single-fraction SRS. We found a differential effect of dose per lesion size and LC by immunotherapy receipt. Future studies are needed to determine whether lower doses of single-fraction SRS afford similarly effective LC for patients with small MBMs receiving immunotherapy.
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Affiliation(s)
- Mehran Yusuf
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Abbas Rattani
- Department of Radiation Oncology, School of Medicine, University of Louisville Hospital, 529 S. Jackson St, Louisville, KY, 40202, USA.
| | - Jeremy Gaskins
- Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, KY, USA
| | | | - Steven F Mandish
- Department of Radiation Oncology, School of Medicine, University of Louisville Hospital, 529 S. Jackson St, Louisville, KY, 40202, USA
| | - Eric Burton
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Michael E May
- Department of Radiation Oncology, School of Medicine, University of Louisville Hospital, 529 S. Jackson St, Louisville, KY, 40202, USA
| | - Brian Williams
- Department of Neurosurgery, University of Louisville Hospital, Louisville, KY, USA
| | - Dale Ding
- Department of Neurosurgery, University of Louisville Hospital, Louisville, KY, USA
| | - Mayur Sharma
- Department of Neurosurgery, University of Louisville Hospital, Louisville, KY, USA
| | - Donald Miller
- Department of Medical Oncology, University of Louisville Hospital, Louisville, KY, USA
| | - Shiao Woo
- Department of Radiation Oncology, School of Medicine, University of Louisville Hospital, 529 S. Jackson St, Louisville, KY, 40202, USA
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Myrehaug S, Hudson J, Soliman H, Ruschin M, Tseng CL, Detsky J, Husain Z, Keith J, Atenafu EG, Maralani P, Heyn C, Das S, Lipsman N, Sahgal A. Hypofractionated Stereotactic Radiation Therapy for Intact Brain Metastases in 5 Daily Fractions: Effect of Dose on Treatment Response. Int J Radiat Oncol Biol Phys 2021; 112:342-350. [PMID: 34537313 DOI: 10.1016/j.ijrobp.2021.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/13/2021] [Accepted: 09/01/2021] [Indexed: 01/09/2023]
Abstract
PURPOSE Multileaf collimator (MLC) linear accelerator (Linac)-based hypofractionated stereotactic radiation therapy (HSRT) is increasingly used not only for large brain metastases or those adjacent to critical structures but also for those metastases that would otherwise be considered for single-fraction radiosurgery (SRS). However, data on outcomes in general are limited, and there is a lack of understanding regarding optimal dosing. Our aim was to report mature image-based outcomes for MLC-Linac HSRT with a focus on clinical and dosimetric factors associated with local failure (LF). METHODS AND MATERIALS A total of 220 patients with 334 brain metastases treated with HSRT were identified. All patients were treated using a 5-fraction daily regimen and were followed with clinical evaluation and volumetric magnetic resonance imaging every 2 to 3 months. Overall survival and progression-free survival were calculated using the Kaplan-Meier method, with LF determined using Fine and Gray's competing risk method. Predictive factors were identified using Cox regression multivariate analysis. RESULTS Median follow-up was 10.8 months. Median size of treated metastasis was 1.9 cm; 60% of metastases were <2 cm in size. The median total dose was 30 Gy in 5 fractions; 36% of the cohort received <30 Gy. The median time to LF and 12-month cumulative incidence of LF was 8.5 months and 23.8%, respectively. Median time to death and 12-month overall survival rates were 11.8 months and 48.2%, respectively. Fifty-two metastases (15.6%) had an adverse radiation effect, of which 32 (9.5%) were symptomatic necrosis. Multivariable analysis identified worse LF in patients who received a total dose of <30 Gy (hazard ratio, 1.62; P = .03), with LF at 6 and 12 months of 13% and 33% for patients treated with <30 Gy versus 5% and 19% for patients treated with >30 Gy. Exploratory analysis demonstrated a dose-response effect observed in all histologic types, including among breast cancer subtypes. CONCLUSION Optimal local control is achieved with HSRT of ≥30 Gy in 5 daily fractions, independent of tumor volume and histology, with an acceptable risk of radiation necrosis.
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Affiliation(s)
- Sten Myrehaug
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada.
| | - John Hudson
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Hany Soliman
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Mark Ruschin
- Department of Medical Physics, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Chia-Lin Tseng
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Jay Detsky
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Zain Husain
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Julia Keith
- Department of Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Eshetu G Atenafu
- Department of Biostatistics, University Health Network, Ontario, Canada
| | - Pejman Maralani
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Chris Heyn
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Sunit Das
- Department of Neurosurgery, St. Michaels Hospital, Ontario, Canada
| | - Nir Lipsman
- Department of Neurosurgery, Sunnybrook Health Sciences Centre, Ontario, Canada
| | - Arjun Sahgal
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Ontario, Canada
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Schelin ME, Liu H, Ali A, Shi W, Yu Y, Mooney KE. Dosimetric comparison of Gamma Knife® Icon TM and linear accelerator-based fractionated stereotactic radiotherapy (FSRT) plans for the re-irradiation of large (>14 cm 3) recurrent glioblastomas. JOURNAL OF RADIOSURGERY AND SBRT 2021; 7:233-243. [PMID: 33898087 PMCID: PMC8055238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Our objective is to investigate dosimetric differences between clinically deliverable Gamma Knife® (GK) Icon™ and linac-based FSRT plans on the basis of normal brain dose sparing for large (>14 cm3) recurrent glioblastomas (GBM). Sixteen patients with large, recurrent GBM were treated using re-irradiation via linac-based FSRT, 35 Gy in 10 fractions. For each patient, a new GK FSRT plan was created in Leksell GammaPlan® V11 (LGP). To maintain clinical deliverability, the LGP optimization included a planning goal of treatment time <20 minutes per fraction. Dosimetric comparison of coverage and normal brain dose between the linac and GK treatment plans was performed in MIM. The GK FSRT plans had significantly (p < 0.05) lower mean normal brain dose values (-8.85%), mean values of normal brain V20 (-32.4%) and V12 (-25.9%), and a lower mean V4 (-10.0%). GK FSRT plans have the potential to reduce the risk of radiation-related toxicities.
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Affiliation(s)
- Matthew E Schelin
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
| | - Haisong Liu
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
| | - Ayesha Ali
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
| | - Wenyin Shi
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
| | - Yan Yu
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
| | - Karen E Mooney
- Department of Radiation Oncology, Thomas Jefferson University, Bodine Center for Radiation Therapy, 111 S. 11th Street, Philadelphia, PA 19107, USA
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Dellios D, Pappas EP, Seimenis I, Paraskevopoulou C, Lampropoulos KI, Lymperopoulou G, Karaiskos P. Evaluation of patient-specific MR distortion correction schemes for improved target localization accuracy in SRS. Med Phys 2020; 48:1661-1672. [PMID: 33230923 DOI: 10.1002/mp.14615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/16/2020] [Accepted: 11/16/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This work aims at promoting target localization accuracy in cranial stereotactic radiosurgery (SRS) applications by focusing on the correction of sequence-dependent (also patient induced) magnetic resonance (MR) distortions at the lesion locations. A phantom-based quality assurance (QA) methodology was developed and implemented for the evaluation of three distortion correction techniques. The same approach was also adapted to cranial MR images used for SRS treatment planning purposes in single or multiple brain metastases cases. METHODS A three-dimensional (3D)-printed head phantom was filled with a 3D polymer gel dosimeter. Following treatment planning and dose delivery, volumes of radiation-induced polymerization served as hypothetical lesions, offering adequate MR contrast with respect to the surrounding unirradiated areas. T1-weighted (T1w) MR imaging was performed at 1.5 T using the clinical scanning protocol for SRS. Additional images were acquired to implement three distortion correction methods; the field mapping (FM), mean image (MI) and signal integration (SI) techniques. Reference lesion locations were calculated as the averaged centroid positions of each target identified in the forward and reverse read gradient polarity MRI scans. The same techniques and workflows were implemented for the correction of contrast-enhanced T1w MR images of 10 patients with a total of 27 brain metastases. RESULTS All methods employed in the phantom study diminished spatial distortion. Median and maximum distortion magnitude decreased from 0.7 mm (2.10 ppm) and 0.8 mm (2.36 ppm), respectively, to <0.2 mm (0.61 ppm) at all target locations, using any of the three techniques. Image quality of the corrected images was acceptable, while contrast-to-noise ratio slightly increased. Results of the patient study were in accordance with the findings of the phantom study. Residual distortion in corrected patient images was found to be <0.3 mm in the vast majority of targets. Overall, the MI approach appears to be the most efficient correction method from the three investigated. CONCLUSIONS In cranial SRS applications, patient-specific distortion correction at the target location(s) is feasible and effective, despite the expense of longer imaging time since additional MRI scan(s) need to be performed. A phantom-based QA methodology was developed and presented to reassure efficient implementation of correction techniques for sequence-dependent spatial distortion.
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Affiliation(s)
- Dimitrios Dellios
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, 115 27, Greece
| | - Eleftherios P Pappas
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, 115 27, Greece
| | - Ioannis Seimenis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, 115 27, Greece
| | | | - Kostas I Lampropoulos
- Medical Physics and Gamma Knife Department, Hygeia Hospital, Marousi, 151 23, Greece
| | - Georgia Lymperopoulou
- 1st Department of Radiology, Medical School, National and Kapodistrian University of Athens, Athens, 115 28, Greece
| | - Pantelis Karaiskos
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, 115 27, Greece.,Medical Physics and Gamma Knife Department, Hygeia Hospital, Marousi, 151 23, Greece
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11
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Buatti JS, Buatti JM, Yaddanapudi S, Pennington EC, Wang D, Gross B, St‐Aubin JJ, Hyer DE, Smith MC, Flynn RT. Stereotactic radiotherapy of appropriately selected meningiomas and metastatic brain tumor beds with gamma knife icon versus volumetric modulated arc therapy. J Appl Clin Med Phys 2020; 21:246-252. [PMID: 33207030 PMCID: PMC7769414 DOI: 10.1002/acm2.13100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 09/23/2020] [Accepted: 09/27/2020] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To determine if the gamma knife icon (GKI) can provide superior stereotactic radiotherapy (SRT) dose distributions for appropriately selected meningioma and post-resection brain tumor bed treatments to volumetric modulated arc therapy (VMAT). MATERIALS AND METHODS Appropriately selected targets were not proximal to great vessels, did not have sensitive soft tissue including organs-at-risk (OARs) within the planning target volume (PTV), and did not have concave tumors containing excessive normal brain tissue. Four of fourteen candidate meningioma patients and six of six candidate patients with brain tumor cavities were considered for this treatment planning comparison study. PTVs were generated for GKI and VMAT by adding 1 mm and 3 mm margins, respectively, to the GTVs. Identical PTV V100% -values were obtained for the GKI and VMAT plans for each patient. Meningioma and tumor bed prescription doses were 52.7-54.0 in 1.7-1.8 Gy fractions and 25 Gy in 5 Gy fractions, respectively. GKI dose rate was 3.735 Gy/min for 16 mm collimators. RESULTS PTV radical dose homogeneity index was 3.03 ± 0.35 for GKI and 1.27 ± 0.19 for VMAT. Normal brain D1% , D5% , and D10% were lower for GKI than VMAT by 45.8 ± 10.9%, 38.9 ± 11.5%, and 35.4 ± 16.5% respectively. All OARs considered received lower maximum doses for GKI than VMAT. GKI and VMAT treatment times for meningioma plans were 12.1 ± 4.13 min and 6.2 ± 0.32 min, respectively, and, for tumor cavities, were 18.1 ± 5.1 min and 11.0 ± 0.56 min, respectively. CONCLUSIONS Appropriately selected meningioma and brain tumor bed patients may benefit from GKI-based SRT due to the decreased normal brain and OAR doses relative to VMAT enabled by smaller margins. Care must be taken in meningioma patient selection for SRT with the GKI, even if they are clinically appropriate for VMAT.
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Affiliation(s)
- Jacob S. Buatti
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - John M. Buatti
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Sridhar Yaddanapudi
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Edward C. Pennington
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Dongxu Wang
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Brandie Gross
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Joël J. St‐Aubin
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Daniel E. Hyer
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Mark C. Smith
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
| | - Ryan T. Flynn
- Department of Radiation OncologyUniversity of Iowa Hospital and Clinics200 Hawkins DriveIowa CityIA52242USA
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12
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Seneviratne DS, Hadley AR, Peterson JL, Malouff TD, Reimer R, Herchko SM, May B, Ko S, Trifiletti DM, Vallow LA. Assessment of unintended shifts during frame-based stereotactic radiosurgery using cone beam computed tomography image guidance. J Neurooncol 2020; 148:273-279. [PMID: 32474748 DOI: 10.1007/s11060-020-03463-2] [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] [Received: 12/30/2019] [Accepted: 03/18/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate the frequency, magnitude and possible causes of frame-shifts that may occur between treatment planning and treatment delivery when performing Gamma Knife radiosurgery with rigid frame-based immobilization. METHODS Differences between computed tomography (CT) framed fiducial stereotactic coordinate reference and cone beam computed tomography stereotactic coordinates after image registration were recorded for 49 frame-based GK radiosurgery cases performed using the Gamma Knife Icon. Parameters recorded include rotational shifts, translational shifts, and the GK-computed Maximum Shot Displacement (MSD) between the two stereotactic coordinate spaces. Other patient-specific parameters were collected and linear regression analysis was performed to evaluate predictors of increased displacement. RESULTS The median values of rotational shifts were: pitch 0.14°, yaw 0.17°, and roll 0.13°. The median absolute values of translational shifts were: left-right 0.39 mm, anteroposterior 0.14 mm, and superior-inferior 0. 22 mm. The median value of MSD was 0.71 mm. Twelve cases (24.5%) had a MSD of greater than 1.0 mm. Male gender was associated with increased MSD (p = 0.013) and translational shifts (root-mean-squared value, p = 0.017). Cases with large differences between right and left sided pin lengths were also associated with increased MSD (p = 0.011). CONCLUSIONS The use of CBCT image guidance in frame-based GK radiosurgery allows unintended frame shifts to be identified and corrected. A significant fraction (24.5%) of patients had large enough shifts to result in a MSD of greater than 1.0 mm. Male gender and eccentrically placed frames were associated with increased MSD, and particular care should be taken in these cases.
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Affiliation(s)
- Danushka S Seneviratne
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
| | | | - Jennifer L Peterson
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA.,Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, USA
| | - Timothy D Malouff
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
| | - Ronald Reimer
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, USA
| | - Steve M Herchko
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
| | - Byron May
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
| | - Stephen Ko
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
| | - Daniel M Trifiletti
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA. .,Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, USA.
| | - Laura A Vallow
- Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL, 32224, USA
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13
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Radical Laser Interstitial Thermal Therapy Ablation Volumes Increase Progression-Free Survival in Biopsy-Proven Radiation Necrosis. World Neurosurg 2020; 136:e646-e659. [DOI: 10.1016/j.wneu.2020.01.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/27/2022]
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14
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Mendel JT, Jaster AW, Yu FF, Morris LC, Lynch PT, Shah BR, Agarwal A, Timmerman RD, Nedzi LA, Raj KM. Fundamentals of Radiation Oncology for Neurologic Imaging. Radiographics 2020; 40:827-858. [PMID: 32216705 DOI: 10.1148/rg.2020190138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Although the physical and biologic principles of radiation therapy have remained relatively unchanged, a technologic renaissance has led to continuous and ever-changing growth in the field of radiation oncology. As a result, medical devices, techniques, and indications have changed considerably during the past 20-30 years. For example, advances in CT and MRI have revolutionized the treatment planning process for a variety of central nervous system diseases, including primary and metastatic tumors, vascular malformations, and inflammatory diseases. The resultant improved ability to delineate normal from abnormal tissue has enabled radiation oncologists to achieve more precise targeting and helped to mitigate treatment-related complications. Nevertheless, posttreatment complications still occur and can pose a diagnostic challenge for radiologists. These complications can be divided into acute, early-delayed, and late-delayed complications on the basis of the time that they manifest after radiation therapy and include leukoencephalopathy, vascular complications, and secondary neoplasms. The different irradiation technologies and applications of these technologies in the brain, current concepts used in treatment planning, and essential roles of the radiation oncologist in the setting of brain disease are reviewed. In addition, relevant imaging findings that can be used to delineate the extent of disease before treatment, and the expected posttreatment imaging changes are described. Common and uncommon complications related to radiation therapy and the associated imaging manifestations also are discussed. Familiarity with these entities may aid the radiologist in making the diagnosis and help guide appropriate management. ©RSNA, 2020.
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Affiliation(s)
- J Travis Mendel
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Adam W Jaster
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Fang F Yu
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Lee C Morris
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Patrick T Lynch
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Bhavya R Shah
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Amit Agarwal
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Robert D Timmerman
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Lucien A Nedzi
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Karuna M Raj
- From the Departments of Radiation Oncology (J.T.M., P.T.L., R.D.T., L.A.N.) and Radiology (A.W.J., F.F.Y., L.C.M., B.R.S., A.A., K.M.R.), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
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15
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Prentou G, Pappas EP, Logothetis A, Koutsouveli E, Pantelis E, Papagiannis P, Karaiskos P. Dosimetric impact of rotational errors on the quality of VMAT-SRS for multiple brain metastases: Comparison between single- and two-isocenter treatment planning techniques. J Appl Clin Med Phys 2020; 21:32-44. [PMID: 32022447 PMCID: PMC7075408 DOI: 10.1002/acm2.12815] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/21/2019] [Accepted: 12/10/2019] [Indexed: 12/22/2022] Open
Abstract
Purpose In the absence of a 6D couch and/or assuming considerable intrafractional patient motion, rotational errors could affect target coverage and OAR‐sparing especially in multiple metastases VMAT‐SRS cranial cases, which often involve the concurrent irradiation of off‐axis targets. This work aims to study the dosimetric impact of rotational errors in such applications, under a comparative perspective between the single‐ and two‐isocenter treatment techniques. Methods Ten patients (36 metastases) were included in this study. Challenging cases were only considered, with several targets lying in close proximity to OARs. Two multiarc VMAT plans per patient were prepared, involving one and two isocenters, serving as the reference plans. Different degrees of angular offsets at various orientations were introduced, simulating rotational errors. Resulting dose distributions were evaluated and compared using commonly employed dose‐volume and plan quality indices. Results For single‐isocenter plans and 1⁰ rotations, plan quality indices, such as coverage, conformity index and D95%, deteriorated significantly (>5%) for distant targets from the isocenter (at> 4–6 cm). Contrarily, for two‐isocenter plans, target distances to nearest isocenter were always shorter (≤4 cm), and, consequently, 1⁰ errors were well‐tolerated. In the most extreme case considered (2⁰ around all axes) conformity index deteriorated by on‐average 7.2%/cm of distance to isocenter, if one isocenter is used, and 2.6%/cm, for plans involving two isocenters. The effect is, however, strongly associated with target volume. Regarding OARs, for single‐isocenter plans, significant increase (up to 63%) in Dmax and D0.02cc values was observed for any angle of rotation. Plans that could be considered clinically unacceptable were obtained even for the smallest angle considered, although rarer for the two‐isocenter planning approach. Conclusion Limiting the lesion‐to‐isocenter distance to ≤4 cm by introducing additional isocenter(s) appears to partly mitigate severe target underdosage, especially for smaller target sizes. If OAR‐sparing is also a concern, more stringent rotational error tolerances apply.
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Affiliation(s)
- Georgia Prentou
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleftherios P Pappas
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Andreas Logothetis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - Evaggelos Pantelis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis Papagiannis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Pantelis Karaiskos
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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16
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Goldbaum DS, Hurley JD, Hamilton RJ. A simple knowledge-based tool for stereotactic radiosurgery pre-planning. J Appl Clin Med Phys 2019; 20:97-108. [PMID: 31743563 PMCID: PMC6909177 DOI: 10.1002/acm2.12770] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 08/15/2019] [Accepted: 10/14/2019] [Indexed: 11/16/2022] Open
Abstract
We studied the dosimetry of single‐isocenter treatment plans generated to treat a solitary intracranial lesion using linac‐based stereotactic radiosurgery (SRS). A common metric for evaluating SRS plan quality is the volume of normal brain tissue irradiated by a dose of at least 12 Gy (V12), which is important because multiple studies have shown a strong correlation between V12 and incidence of radiation necrosis. Unrealistic expectations for values of V12 can lead to wasted planning time. We present a model that estimates V12 without having to construct a full treatment plan. This model was derived by retrospectively analyzing 50 SRS treatment plans, each clinically approved for delivery using circular collimator cone arc therapy (CAT). Each case was re‐planned for delivery via dynamic conformal arc therapy (DCAT), and then scaling arguments were used to extend dosimetric data to account for different prescription dose (PD) values (15, 18, 21, or 24 Gy). We determined a phenomenological expression for the total volume receiving at least 12 Gy (TV12) as a function of both planning target volume (PTV) and PD: TV12/1cc=n∗PD/1Gy+d∗PTV/1cca∗PD/1Gyc, where a,c,n,d are fit parameters, and a separate set of values is determined for each plan type. In addition, we generated a sequence of plots to clarify how the relationship between conformity index (CI) and TV12 depends on plan type (CAT vs DCAT), PTV, and PD. These results can be used to suggest realistic plan parameters and planning goals before the start of treatment planning. In the absence of access to more sophisticated pre‐planning tools, this model can be locally generated and implemented at relatively low cost with respect to time, money, and expertise.
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Affiliation(s)
- Daniel S Goldbaum
- Department of Radiation Oncology, University of Arizona, Tucson, AZ, USA
| | - Justin D Hurley
- Department of Radiation Oncology, University of Arizona, Tucson, AZ, USA
| | - Russell J Hamilton
- Department of Radiation Oncology, University of Arizona, Tucson, AZ, USA
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17
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Dong P, Pérez-Andújar A, Pinnaduwage D, Braunstein S, Theodosopoulos P, McDermott M, Sneed P, Ma L. Dosimetric characterization of hypofractionated Gamma Knife radiosurgery of large or complex brain tumors versus linear accelerator-based treatments. J Neurosurg 2018; 125:97-103. [PMID: 27903198 DOI: 10.3171/2016.7.gks16881] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Noninvasive Gamma Knife (GK) platforms, such as the relocatable frame and on-board imaging, have enabled hypofractionated GK radiosurgery of large or complex brain lesions. This study aimed to characterize the dosimetric quality of such treatments against linear accelerator-based delivery systems that include the CyberKnife (CK) and volumetric modulated arc therapy (VMAT). METHODS Ten patients treated with VMAT at the authors' institution for large brain tumors (> 3 cm in maximum diameter) were selected for the study. The median prescription dose was 25 Gy (range 20-30 Gy) in 5 fractions. The median planning target volume (PTV) was 9.57 cm3 (range 1.94-24.81 cm3). Treatment planning was performed using Eclipse External Beam Planning V11 for VMAT on the Varian TrueBeam system, Multiplan V4.5 for the CyberKnife VSI System, and Leksell GammaPlan V10.2 for the Gamma Knife Perfexion system. The percentage of the PTV receiving at least the prescription dose was normalized to be identical across all platforms for individual cases. The prescription isodose value for the PTV, conformity index, Paddick gradient index, mean and maximum doses for organs at risk, and normal brain dose at variable isodose volumes ranging from the 5-Gy isodose volume (V5) to the 15-Gy isodose volume (V15) were compared for all of the cases. RESULTS The mean Paddick gradient index was 2.6 ± 0.2, 3.2 ± 0.5, and 4.3 ± 1.0 for GK, CK, and VMAT, respectively (p < 0.002). The mean V15 was 7.5 ± 3.7 cm3 (range 1.53-13.29 cm3), 9.8 ± 5.5 cm3 (range 2.07-18.45 cm3), and 16.1 ± 10.6 cm3 (range 3.58-36.53 cm3) for GK, CK, and VMAT, respectively (p ≤ 0.03, paired 2-tailed t-tests). However, the average conformity index was 1.18, 1.12, and 1.21 for GK, CK, and VMAT, respectively (p > 0.06). The average prescription isodose values were 52% (range 47%-69%), 60% (range 46%-68%), and 88% (range 70%-94%) for GK, CK, and VMAT, respectively, thus producing significant variations in dose hot spots among the 3 platforms. Furthermore, the mean V5 values for GK and CK were similar (p > 0.79) at 71.9 ± 36.2 cm3 and 73.3 ± 31.8 cm3, respectively, both of which were statistically lower (p < 0.01) than the mean V5 value of 124.6 ± 67.1 cm3 for VMAT. CONCLUSIONS Significantly better near-target normal brain sparing was noted for hypofractionated GK radiosurgery versus linear accelerator-based treatments. Such a result supports the use of a large number of isocenters or confocal beams for the benefit of normal tissue sparing in hypofractionated brain radiosurgery.
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Affiliation(s)
- Peng Dong
- Departments of 1 Radiation Oncology and.,Department of Radiation Oncology, Stanford University, Stanford, California; and
| | | | - Dilini Pinnaduwage
- Department of Radiation Oncology, The University of Arizona School of Medicine and St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | | | | | | | | | - Lijun Ma
- Departments of 1 Radiation Oncology and
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18
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Tailored Treatment Options for Patients with Brain Metastases by a Relocatable Frame System with Gamma Knife Radiosurgery. World Neurosurg 2018; 119:e338-e348. [PMID: 30059780 DOI: 10.1016/j.wneu.2018.07.157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To report on our experience with the Elekta Extend system, a relocatable frame system used in patients with brain metastases for single-session, hypofractionated, or staged hypofractionated Gamma Knife radiosurgery (GKRS); and the evaluation of its efficacy. METHODS From March 2014 to September 2016, 856 patients with brain metastases underwent GKRS at our hospital. Of them, 35 patients who were retrospectively investigated, were selected for treatment with GKRS using the relocatable frame system. Individualized treatment strategy was chosen according to prior treatment history, number, size and location of tumor, or tumor harboring gene mutation. RESULTS Thirty-two (91.4%) patients underwent treatment with hypofractionated GKRS or staged hypofractionated GKRS, whereas 3 (8.6%) patients underwent single session GKRS. The mean radial setup difference from the reference measurements was 0.50 ± 0.16 mm. The median follow-up time after GKRS with the Extend system was 12 months (range, 1-45 months). The median overall survival time was 12 months (95% confidence interval 6.43-17.57). On multivariable analysis, performance status and extracranial metastases were independently prognostic factors for overall survival. Radiation necrosis developed in 4 cases (11.4%) during the follow-up period (2 with common terminology criteria for adverse events grade 2 and 2 with its grade 3). CONCLUSIONS The relocatable frame system can maintain submillimetric accuracy and provide tailored treatment option with reasonable tumor control and good survival benefits in selected patients with brain metastases. Especially, hypofractionated GKRS or staged hypofractionated GKRS with noninvasive frame is a safe and effective treatment option for large brain metastases or tumor adjacent to eloquent structures.
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19
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Pappas EP, Seimenis I, Dellios D, Kollias G, Lampropoulos KI, Karaiskos P. Assessment of sequence dependent geometric distortion in contrast-enhanced MR images employed in stereotactic radiosurgery treatment planning. ACTA ACUST UNITED AC 2018; 63:135006. [DOI: 10.1088/1361-6560/aac7bf] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Eaton DJ, Lee J, Paddick I. Stereotactic radiosurgery for multiple brain metastases: Results of multicenter benchmark planning studies. Pract Radiat Oncol 2017; 8:e212-e220. [PMID: 29452865 DOI: 10.1016/j.prro.2017.12.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/08/2017] [Accepted: 12/20/2017] [Indexed: 11/17/2022]
Abstract
PURPOSE Stereotactic radiosurgery is indicated for treatment of multiple brain metastases. Various treatment platforms are available, but most comparisons are limited to single-center studies. As part of a national commissioning program, benchmark planning cases were completed by 21 clinical centers, providing a unique dataset of current practice across a large number of providers and equipment platforms. METHODS AND MATERIALS Two brain metastases cases were provided, with images and structures predrawn, involving 3 and 7 lesions. Centers produced plans according to their local practice, which were reviewed centrally using metrics for target coverage, selectivity, gradient fall-off, and normal tissue sparing. RESULTS Fifty plans were submitted, using 24 treatment platforms. Eleven plans were revised following feedback, including 2 centers that acquired a new platform; 1 other center accepted a restriction of service. All centers prioritized coverage, with the prescription isodose covering ≥95% of 233 of 235 target volumes. Selectivity was much more variable, especially for smaller lesions, and when combined with poor gradient indices resulted in large volumes of normal tissue being irradiated. Tomotherapy submissions were outliers for either selectivity or gradient index, but other platforms could produce plans with relatively low gradient indices for larger lesion volumes. There was more variation among Varian and Elekta LINAC plans than for Gamma Knife and CyberKnife, and larger differences for smaller targets, both inter- and intratreatment platform. Doses to normal brain and brainstem were highest when margins were applied, but improvements were possible by replanning alone. CONCLUSIONS Multicenter benchmarking exercises have highlighted some variation in clinical practice and priorities, with a few outliers. Most platforms are able to achieve comparable plans, except for the smallest volumes and when larger planning margins are used. The data will be used to advance standardization and quality improvement of national services and can provide useful guidance for centers worldwide.
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Affiliation(s)
- David J Eaton
- National Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, Northwood, United Kingdom.
| | - Jonathan Lee
- National Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, Northwood, United Kingdom
| | - Ian Paddick
- Medical Physics Ltd, Reading, United Kingdom; Cromwell Hospital, London, United Kingdom
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21
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Zhao B, Wen N, Chetty IJ, Huang Y, Brown SL, Snyder KC, Siddiqui F, Movsas B, Siddiqui MS. A prediction model of radiation-induced necrosis for intracranial radiosurgery based on target volume. Med Phys 2017; 44:4360-4367. [PMID: 28543402 DOI: 10.1002/mp.12360] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/22/2017] [Accepted: 05/11/2017] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This study aims to extend the observation that the 12 Gy-radiosurgical-volume (V12Gy) correlates with the incidence of radiation necrosis in patients with intracranial tumors treated with radiosurgery by using target volume to predict V12Gy. V12Gy based on the target volume was used to predict the radiation necrosis probability (P) directly. Also investigated was the reduction in radiation necrosis rates (ΔP) as a result of optimizing the prescription isodose lines for linac-based SRS. METHODS Twenty concentric spherical targets and 22 patients with brain tumors were retrospectively studied. For each case, a standard clinical plan and an optimized plan with prescription isodose lines based on gradient index were created. V12Gy were extracted from both plans to analyze the correlation between V12Gy and target volume. The necrosis probability P as a function of V12Gy was evaluated. To account for variation in prescription, the relation between V12Gy and prescription was also investigated. RESULTS A prediction model for radiation-induced necrosis was presented based on the retrospective study. The model directly relates the typical prescribed dose and the target volume to the radionecrosis probability; V12Gy increased linearly with the target volume (R2 > 0.99). The linear correlation was then integrated into a logistic model to predict P directly from the target volume. The change in V12Gy as a function of prescription was modeled using a single parameter, s (=-1.15). Relatively large ΔP was observed for target volumes between 7 and 28 cm3 with the maximum reduction (8-9%) occurring at approximately 18 cm3 . CONCLUSIONS Based on the model results, optimizing the prescription isodose line for target volumes between 7 and 28 cm3 results in a significant reduction in necrosis probability. V12Gy based on the target volume could provide clinicians a predictor of radiation necrosis at the contouring stage thus facilitating treatment decisions.
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Affiliation(s)
- Bo Zhao
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Ning Wen
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Indrin J Chetty
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Yimei Huang
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Stephen L Brown
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Karen C Snyder
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Farzan Siddiqui
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - Benjamin Movsas
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
| | - M Salim Siddiqui
- Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI, 48202, USA
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Sahgal A, Ruschin M, Ma L, Verbakel W, Larson D, Brown PD. Stereotactic radiosurgery alone for multiple brain metastases? A review of clinical and technical issues. Neuro Oncol 2017; 19:ii2-ii15. [PMID: 28380635 DOI: 10.1093/neuonc/nox001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Over the past three decades several randomized trials have enabled evidence-based practice for patients presenting with limited brain metastases. These trials have focused on the role of surgery or stereotactic radiosurgery (SRS) with or without whole brain radiation therapy (WBRT). As a result, it is clear that local control should be optimized with surgery or SRS in patients with optimal prognostic factors presenting with up to 4 brain metastases. The routine use of adjuvant WBRT remains debatable, as although greater distant brain control rates are observed, there is no impact on survival, and modern outcomes suggest adverse effects from WBRT on patient cognition and quality of life. With dramatic technologic advances in radiation oncology facilitating the adoption of SRS into mainstream practice, the optimal management of patients with multiple brain metastases is now being put forward. Practice is evolving to SRS alone in these patients despite a lack of level 1 evidence to support a clinical departure from WBRT. The purpose of this review is to summarize the current state of the evidence for patients presenting with limited and multiple metastases, and to present an in-depth analysis of the technology and dosimetric issues specific to the treatment of multiple metastases.
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Affiliation(s)
- Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Mark Ruschin
- Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Lijun Ma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Wilko Verbakel
- Department of Radiation Oncology, VU University Medical Center, Amsterdam,The Netherlands
| | - David Larson
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Paul D Brown
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
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Chiu J, Pierce M, Braunstein SE, Theodosopoulos PV, McDermott MW, Sneed PK, Ma L. Sharpening peripheral dose gradient via beam number enhancement from patient head tilt for stereotactic brain radiosurgery. Phys Med Biol 2016; 61:N532-N541. [DOI: 10.1088/0031-9155/61/20/n532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ma L, Braunstein SE, Theodosopoulos PV, McDermott MW, Sneed PK. Inherent functional dependence among cochlear dose surrogates for stereotactic radiosurgery of vestibular schwannomas. Pract Radiat Oncol 2016; 7:e1-e7. [PMID: 27742557 DOI: 10.1016/j.prro.2016.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/25/2016] [Accepted: 08/15/2016] [Indexed: 12/31/2022]
Abstract
PURPOSE Various cochlear dose surrogates have been reported as associated with hearing outcome in studies of stereotactic radiosurgery (SRS) for vestibular schwannomas. In this study, we investigated whether an inherent functional relationship exists among these reported surrogates. METHODS AND MATERIALS A cohort of 85 serial patient cases treated with single-fraction stereotactic radiosurgery from 1997 through 2013 at our institution was analyzed. For all the cases, the mean prescription dose was 12.5 ± 0.3 Gy (range, 12-13 Gy) and mean target volume 1.32 ± 1.51 mL (range, 0.80-8.77 mL). The mean cochlea volume was 0.078 ± 0.016 mL (range, 0.048-0.131 mL; median, 0.076 mL). Correlation analysis among mean cochlear dose, point maximum dose and modiolus dose was performed and also parameterized with new variables such as the effective dose radius (EDR) as derived from a general dose fall-off model. RESULTS Weak correlation via linear regression was found between the point maximum dose and the mean cochlear dose (R2 = 0.719) as well as the modiolus dose (R2 = 0.568). However, when parameterized with EDR, a near-perfect correlation (P < .0001) via linear regression was found between the EDR for the point maximum dose and the EDR for the mean cochlear dose (R2 = 0.996), and with the EDR for the modiolus dose (R2 = 0.993). Such a result led to a functional formula relating these dose surrogates, yielding dose equivalence results such as: 12-Gy point maximum dose is equivalent to mean cochlear dose of 5.6 ± 0.1 Gy (95% confidence level), or modiolus dose of 6.0 ± 0.2 Gy (95% confidence level). CONCLUSIONS An inherent functional relationship was found among point maximum, modiolus, and mean cochlear doses for SRS of vestibular schwannomas. As such, clinical hearing outcome can be interchangeably analyzed or reported via any of these dose surrogates.
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Affiliation(s)
- Lijun Ma
- Department of Radiation Oncology, University of California, San Francisco, California.
| | - Steve E Braunstein
- Department of Radiation Oncology, University of California, San Francisco, California
| | | | - Michael W McDermott
- Department of Neurosurgery, University of California, San Francisco, California
| | - Penny K Sneed
- Department of Radiation Oncology, University of California, San Francisco, California
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Amsbaugh M, Pan J, Yusuf MB, Dragun A, Dunlap N, Guan T, Boling W, Rai S, Woo S. Dose-Volume Response Relationship for Brain Metastases Treated with Frameless Single-Fraction Linear Accelerator-Based Stereotactic Radiosurgery. Cureus 2016; 8:e587. [PMID: 27284495 PMCID: PMC4889452 DOI: 10.7759/cureus.587] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Our aim was to identify a dose-volume response relationship for brain metastases treated with frameless stereotactic radiosurgery (SRS). METHODS We reviewed patients who underwent frameless single-fraction linear accelerator SRS for brain metastases between 2007 and 2013 from an institutional database. Proportional hazards modeling was used to identify predictors of outcome. A ratio of maximum lesion dose per mm-diameter (Gy/mm) was constructed to establish a dose-volume relationship. RESULTS There were 316 metastases evaluated in 121 patients (2 - 33 mm in the largest diameter). The median peripheral dose was 18.0 Gy (range: 10.0 - 24.0 Gy). Local control was 84.8% for all lesions and was affected by location, peripheral dose, maximum dose, and lesion size (p values < 0.050). A dose-volume response relationship was constructed using the maximum dose and lesion size. A unit increase in Gy/mm was associated with decreased local failure (p = 0.005). Local control of 80%, 85%, and 90% corresponded to maximum doses per millimeter of 1.67 Gy/mm, 2.86 Gy/mm, and 4.4 Gy/mm, respectively. Toxicity was uncommon and only 1.0% of lesions developed radionecrosis requiring surgery. CONCLUSIONS For brain metastases less than 3 cm, a dose-volume response relationship exists between maximum radiosurgical dose and lesion size, which is predictive of local control.
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Affiliation(s)
| | - Jianmin Pan
- JG Brown Cancer Center, University of Louisville
| | | | | | - Neal Dunlap
- Radiation Oncology, University of Louisville
| | | | | | - Shesh Rai
- Bioinformatics and Biostatistics, University of Louisville
| | - Shiao Woo
- Radiation Oncology, University of Louisville
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Li W, Cho YB, Ansell S, Laperriere N, Ménard C, Millar BA, Zadeh G, Kongkham P, Bernstein M, Jaffray DA, Chung C. The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation. Int J Radiat Oncol Biol Phys 2016; 96:214-20. [PMID: 27511857 DOI: 10.1016/j.ijrobp.2016.04.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/26/2016] [Accepted: 04/11/2016] [Indexed: 11/28/2022]
Abstract
PURPOSE The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK). METHODS AND MATERIALS Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board-approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured for each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion. RESULTS We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error ± standard deviation in the left-right, anteroposterior, and craniocaudal directions was -0.19 ± 0.32, 0.06 ± 0.27, and -0.23 ± 0.2 mm, with a maximum of -0.74, -0.53, and -0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error ± standard deviation for the LCF was -0.03 ± 0.05, -0.03 ± 0.18, and -0.03 ± 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively. CONCLUSIONS Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non-frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction discrepancy when moving to a frameless approach.
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Affiliation(s)
- Winnie Li
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Young-Bin Cho
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Steve Ansell
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Normand Laperriere
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Cynthia Ménard
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Barbara-Ann Millar
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Gelareh Zadeh
- Division of Neurosurgery, University of Toronto University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada; Macfeeters-Hamilton Centre for Neuro-oncology, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Paul Kongkham
- Division of Neurosurgery, University of Toronto University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Mark Bernstein
- Division of Neurosurgery, University of Toronto University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - David A Jaffray
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Caroline Chung
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.
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Hossain S, Keeling V, Hildebrand K, Ahmad S, Larson DA, Sahgal A, Ma L. Normal Brain Sparing With Increasing Number of Beams and Isocenters in Volumetric-Modulated Arc Beam Radiosurgery of Multiple Brain Metastases. Technol Cancer Res Treat 2015; 15:766-771. [PMID: 26596914 DOI: 10.1177/1533034615614208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 11/15/2022] Open
Abstract
Recent studies have reported about the application of volumetric-modulated arc radiotherapy in the treatment of multiple brain metastases. One of the key concerns for these radiosurgical treatments lies in the integral dose within the normal brain tissue, as it has been shown to increase with increasing number of brain tumors treated. In this study, we investigate the potential to improve normal brain tissue sparing specific to volumetric-modulated arc radiotherapy by increasing the number of isocenters and arc beams. Adopting a multi-institutional benchmark study protocol of planning multiple brain metastases via a radiosurgical apparatus, a flattening filter-free TrueBeam RapidArc delivery system (Varian Oncology, Palo Alto, California) was used for a volumetric-modulated arc radiotherapy treatment planning study, where treatment plans for target combinations of N = 1, 3, 6, 9, and 12 targets were developed with increasing numbers of isocenters and arc beams. The treatment plans for each target combination were compared dosimetrically among each other and against the reference Gamma Knife treatment plan from the original benchmark study. We observed that as the number of isocenters or arc beams increased, the normal brain isodose volumes such as 12- to 4-Gy on average decreased by up to 15% for all the studied cases. However, when the best volumetric-modulated arc radiotherapy normal brain isodose volumes were compared against the corresponding reference Gamma Knife values, volumetric-modulated arc radiotherapy remained 100% to 200% higher than those of Gamma Knife for all target combinations. The study results, particularly for the solitary (N = 1) metastases case, directly challenged the general notion of dose equivalence among current radiosurgical modalities. In conclusion, multiple isocenter and multiple arc beam delivery solutions are capable of decreasing normal brain irradiation exposure for volumetric-modulated arc radiotherapy. However, there is further technological development in need for volumetric-modulated arc radiotherapy before similar dosimetric treatment plans could be achievable when compared to Gamma Knife radiosurgery.
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Affiliation(s)
- Sabbir Hossain
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Vance Keeling
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kimberly Hildebrand
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Salahuddin Ahmad
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - David A Larson
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Odette Cancer Center, University of Toronto, Toronto, Ontario, Canada
| | - Lijun Ma
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
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Implementation and validation of a new fixation system for stereotactic radiation therapy: An analysis of patient immobilization. Pract Radiat Oncol 2015. [DOI: 10.1016/j.prro.2015.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Amsbaugh MJ, Boling W, Woo S. Tumor bed radiosurgery: an emerging treatment for brain metastases. J Neurooncol 2015; 123:197-203. [PMID: 25911296 DOI: 10.1007/s11060-015-1789-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/20/2015] [Indexed: 11/26/2022]
Abstract
While typically used for treating small intact brain metastases, an increasing body of literature examining tumor bed directed stereotactic radiosurgery (SRS) is emerging. There are now over 1000 published cases treated with this approach, and the first prospective trial was recently published. The ideal sequencing of tumor bed SRS is unclear. Current approaches include, a neoadjuvant treatment before resection, alone as an adjuvant after resection, and following surgery combined with whole brain radiotherapy either as an adjuvant or salvage treatment. Based on available evidence, adjuvant stereotactic radiosurgery improves local control following surgery, reduces the number of patients who require whole brain radiotherapy, and is well tolerated. While results from published series vary, heterogeneity in both patient populations and methods of reporting results make comparisons difficult. Additional prospective data, including randomized trials are needed to confirm equivalent outcomes to the current standard of care. We review the current literature, identify areas of ongoing contention, and highlight ongoing studies.
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Affiliation(s)
- Mark J Amsbaugh
- Department of Radiation Oncology, Brown Cancer Center, University of Louisville, 529 S. Jackson Street, Louisville, KY, 40206, USA,
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Ruschin M, Lee Y, Beachey D, Yeboah C, Wronski M, Babic S, Lochray F, Nico A, Khan L, Soliman H, Sahgal A. Investigation of Dose Falloff for Intact Brain Metastases and Surgical Cavities Using Hypofractionated Volumetric Modulated Arc Radiotherapy. Technol Cancer Res Treat 2015; 15:130-8. [PMID: 25627201 DOI: 10.1177/1533034614567277] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 12/05/2014] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Intact brain metastases tend to be small and spherical compared to postsurgery brain cavities, which tend to be large and irregular shaped and, as a result, a challenge with respect to treatment planning. The purpose of the present study is to develop guidelines for normal brain tissue dose and to investigate whether there is a dependence on target type for patients treated with hypofractionated volumetric modulated arc radiotherapy (HF-VMAT). METHODS Treatment plans from a total of 100 patients and 136 targets (55 cavity and 81 intact) were retrospectively reviewed. All targets were treated with HF-VMAT with total doses ranging between 20 and 30 gray (Gy) in 5 fractions. All plans met institutional objectives for organ-at-risk constraints and were clinically delivered. Dose falloff was quantified using gradient index (GI) and distance between the 100% and 50% isodose lines (R50). Additionally, the dose to normal brain tissue (brain contour excluding all gross tumor or clinical target volumes) was assessed using volume receiving specific doses (Vx) where x ranged from 5 to 30 Gy. Best-fit curves using power law relationships of the form y = ax(b) were generated for GI, R50, and Vx (normal brain tissue) versus target volume. RESULTS There was a statistically significant difference in planning target volume (PTV) for cavities versus intact metastases with mean volumes of 37.8 cm(3) and 9.5 cm(3), respectively (P < .0001). The GI and R50 were statistically different: 3.4 and 9.8 mm for cavities versus 4.6 and 8.3 mm for intact metastases (P < .0001). The R50 increased with PTV with power law coefficients (a, b) = (6.3, 0.12) and (5.9, 0.15) for cavities and intact, respectively. GI decreased with PTV with coefficients (a, b) = (5.9, -0.18) and (5.7, -0.14) for cavities and intact, respectively. The normal brain tissue Vx also exhibited power law relationships with PTV for x = 20 to 28.8 Gy. In conclusion, target volume is the main predictor of dose falloff. The results of the present study can be used for determining target volume-based thresholds for dose falloff and normal brain tissue dose-volume constraints.
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Affiliation(s)
- Mark Ruschin
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Young Lee
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - David Beachey
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Collins Yeboah
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Matt Wronski
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Steven Babic
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Fiona Lochray
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Anula Nico
- Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Luluel Khan
- Department of Radiation Oncology, University of Toronto, Toronto, Canada Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Hany Soliman
- Department of Radiation Oncology, University of Toronto, Toronto, Canada Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Canada
| | - Arjun Sahgal
- Department of Radiation Oncology, University of Toronto, Toronto, Canada Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Canada
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Kirkpatrick JP, Wang Z, Sampson JH, McSherry F, Herndon JE, Allen KJ, Duffy E, Hoang JK, Chang Z, Yoo DS, Kelsey CR, Yin FF. Defining the optimal planning target volume in image-guided stereotactic radiosurgery of brain metastases: results of a randomized trial. Int J Radiat Oncol Biol Phys 2014; 91:100-8. [PMID: 25442342 DOI: 10.1016/j.ijrobp.2014.09.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/27/2014] [Accepted: 09/02/2014] [Indexed: 11/15/2022]
Abstract
PURPOSE To identify an optimal margin about the gross target volume (GTV) for stereotactic radiosurgery (SRS) of brain metastases, minimizing toxicity and local recurrence. METHODS AND MATERIALS Adult patients with 1 to 3 brain metastases less than 4 cm in greatest dimension, no previous brain radiation therapy, and Karnofsky performance status (KPS) above 70 were eligible for this institutional review board-approved trial. Individual lesions were randomized to 1- or 3- mm uniform expansion of the GTV defined on contrast-enhanced magnetic resonance imaging (MRI). The resulting planning target volume (PTV) was treated to 24, 18, or 15 Gy marginal dose for maximum PTV diameters less than 2, 2 to 2.9, and 3 to 3.9 cm, respectively, using a linear accelerator-based image-guided system. The primary endpoint was local recurrence (LR). Secondary endpoints included neurocognition Mini-Mental State Examination, Trail Making Test Parts A and B, quality of life (Functional Assessment of Cancer Therapy-Brain), radionecrosis (RN), need for salvage radiation therapy, distant failure (DF) in the brain, and overall survival (OS). RESULTS Between February 2010 and November 2012, 49 patients with 80 brain metastases were treated. The median age was 61 years, the median KPS was 90, and the predominant histologies were non-small cell lung cancer (25 patients) and melanoma (8). Fifty-five, 19, and 6 lesions were treated to 24, 18, and 15 Gy, respectively. The PTV/GTV ratio, volume receiving 12 Gy or more, and minimum dose to PTV were significantly higher in the 3-mm group (all P<.01), and GTV was similar (P=.76). At a median follow-up time of 32.2 months, 11 patients were alive, with median OS 10.6 months. LR was observed in only 3 lesions (2 in the 1 mm group, P=.51), with 6.7% LR 12 months after SRS. Biopsy-proven RN alone was observed in 6 lesions (5 in the 3-mm group, P=.10). The 12-month DF rate was 45.7%. Three months after SRS, no significant change in neurocognition or quality of life was observed. CONCLUSIONS SRS was well tolerated, with low rates of LR and RN in both cohorts. However, given the higher potential risk of RN with a 3-mm margin, a 1-mm GTV expansion is more appropriate.
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Affiliation(s)
- John P Kirkpatrick
- Department of Radiation Oncology, Duke University, Durham, North Carolina; Department of Surgery, Duke University, Durham, North Carolina.
| | - Zhiheng Wang
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - John H Sampson
- Department of Radiation Oncology, Duke University, Durham, North Carolina; Department of Surgery, Duke University, Durham, North Carolina
| | - Frances McSherry
- Department of Biostatistics & Bioinformatics, Duke University, Durham, North Carolina
| | - James E Herndon
- Department of Biostatistics & Bioinformatics, Duke University, Durham, North Carolina
| | - Karen J Allen
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - Eileen Duffy
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - Jenny K Hoang
- Department of Radiology, Duke University, Durham, North Carolina
| | - Zheng Chang
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - David S Yoo
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - Chris R Kelsey
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - Fang-Fang Yin
- Department of Radiation Oncology, Duke University, Durham, North Carolina
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Karaiskos P, Moutsatsos A, Pappas E, Georgiou E, Roussakis A, Torrens M, Seimenis I. A simple and efficient methodology to improve geometric accuracy in gamma knife radiation surgery: implementation in multiple brain metastases. Int J Radiat Oncol Biol Phys 2014; 90:1234-41. [PMID: 25442348 DOI: 10.1016/j.ijrobp.2014.08.349] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 08/02/2014] [Accepted: 08/28/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE To propose, verify, and implement a simple and efficient methodology for the improvement of total geometric accuracy in multiple brain metastases gamma knife (GK) radiation surgery. METHODS AND MATERIALS The proposed methodology exploits the directional dependence of magnetic resonance imaging (MRI)-related spatial distortions stemming from background field inhomogeneities, also known as sequence-dependent distortions, with respect to the read-gradient polarity during MRI acquisition. First, an extra MRI pulse sequence is acquired with the same imaging parameters as those used for routine patient imaging, aside from a reversal in the read-gradient polarity. Then, "average" image data are compounded from data acquired from the 2 MRI sequences and are used for treatment planning purposes. The method was applied and verified in a polymer gel phantom irradiated with multiple shots in an extended region of the GK stereotactic space. Its clinical impact in dose delivery accuracy was assessed in 15 patients with a total of 96 relatively small (<2 cm) metastases treated with GK radiation surgery. RESULTS Phantom study results showed that use of average MR images eliminates the effect of sequence-dependent distortions, leading to a total spatial uncertainty of less than 0.3 mm, attributed mainly to gradient nonlinearities. In brain metastases patients, non-eliminated sequence-dependent distortions lead to target localization uncertainties of up to 1.3 mm (mean: 0.51 ± 0.37 mm) with respect to the corresponding target locations in the "average" MRI series. Due to these uncertainties, a considerable underdosage (5%-32% of the prescription dose) was found in 33% of the studied targets. CONCLUSIONS The proposed methodology is simple and straightforward in its implementation. Regarding multiple brain metastases applications, the suggested approach may substantially improve total GK dose delivery accuracy in smaller, outlying targets.
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Affiliation(s)
- Pantelis Karaiskos
- Medical Physics Laboratory, Medical School, University of Athens, Greece; Gamma Knife Department, Hygeia Hospital, Athens, Greece.
| | - Argyris Moutsatsos
- Medical Physics Laboratory, Medical School, University of Athens, Greece
| | - Eleftherios Pappas
- Medical Physics Laboratory, Medical School, University of Athens, Greece
| | - Evangelos Georgiou
- Medical Physics Laboratory, Medical School, University of Athens, Greece
| | | | | | - Ioannis Seimenis
- Medical Physics Laboratory, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
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