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Pokhrel D, Misa J, McCarthy S, Yang ES. Two novel stereotactic radiotherapy methods for locally advanced, previously irradiated head and neck cancers patients. Med Dosim 2023; 49:114-120. [PMID: 37867087 DOI: 10.1016/j.meddos.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/08/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023]
Abstract
To determine the feasibility and utility of conebeam CT-guided stereotactic radiotherapy for locally recurrent, previously irradiated head and neck cancer (HNC) patients on the Halcyon, a ring delivery system (RDS). This research aims to quantify plan quality, treatment delivery accuracy, and overall efficacy by comparing against novel clinical TrueBeam HyperArc method. Ten recurrent HNC patients who were treated at our institution on TrueBeam (6MV-FFF) for 30 to 40 Gy in 3 to 5 fractions with noncoplanar HyperArc plans were re-planned on Halcyon (6MV-FFF). These plans were re-planned with the same Acuros-based dose engine. Additionally, we used site-specific full/partial coplanar VMAT arcs. PTV coverage, mean dose to GTV, maximum dose to organs-at-risk (OAR), beam-on time (BOT), and quality assurance (QA) results were investigated and compared. Halcyon provided highly conformal HNC SRT plans with slightly superior mean PTVD99 coverage (96.7% vs 95.5%, p = 0.071), and slightly lower mean GTV dose (37.8 Gy vs 38.2 Gy, p = 0.241) when compared to the HyperArc plans. Differences in plan conformality and maximum dose to OARs were statistically insignificant. Due to Halcyon's coplanar geometry, D2cm was significantly higher (p = 0.001) but Halcyon did result in a reduced normal brain dose by 1 Gy on average and up to 5.2 Gy in some cases. Halcyon provided similar patient-specific QA pass rates with a 2%/2mm gamma criteria (98.2% vs 98.5%) and independent in-house Monte Carlo second check results (97.7% vs 98.2%), suggesting identical treatment delivery accuracy. Halcyon plans resulted in slightly longer beam-on time (3.16 vs 2.30 minutes, p = 0.010), however door-to-door patient time is expected to be <10 minutes. Compared to clinical TrueBeam HyperArc, Halcyon SRT plans provided similar plan quality and treatment delivery accuracy with a potentially faster overall treatment using fully automated patient setup and verification. Rapid delivery of recurrent HNC SRT may reduce intrafraction motion errors while also improving patient compliance and comfort. To provide high-quality of HNC SRT similar to HyperArc, we recommend Halcyon users consider commissioning this novel method. This method will be useful for remote and underserved patient cohorts including Halcyon-only clinics as well.
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Affiliation(s)
- Damodar Pokhrel
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
| | - Josh Misa
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Shane McCarthy
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Eddy S Yang
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
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Ramesh P, Valdes G, O'Connor D, Sheng K. A unified path seeking algorithm for IMRT and IMPT beam orientation optimization. Phys Med Biol 2023; 68:195011. [PMID: 37659406 DOI: 10.1088/1361-6560/acf63f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 09/01/2023] [Indexed: 09/04/2023]
Abstract
Objective. Fully automated beam orientation optimization (BOO) for intensity-modulated radiotherapy and intensity modulated proton therapy (IMPT) is gaining interest, since achieving optimal plan quality for an unknown number of fixed beam arrangements is tedious. Fast group sparsity-based optimization methods have been proposed to find the optimal orientation, but manual tuning is required to eliminate the exact number of beams from a large candidate set. Here, we introduce a fast, automated gradient descent-based path-seeking algorithm (PathGD), which performs fluence map optimization for sequentially added beams, to visualize the dosimetric benefit of one added field at a time.Approach. Several configurations of 2-4 proton and 5-15 photon beams were selected for three head-and-neck patients using PathGD, which was compared to group sparsity-regularized BOO solved with the fast iterative shrinkage-thresholding algorithm (GS-FISTA), and manually selected IMPT beams or one coplanar photon VMAT arc (MAN). Once beams were chosen, all plans were compared on computational efficiency, dosimetry, and for proton plans, robustness.Main results. With each added proton beam, Clinical Target Volume (CTV) and organs at risk (OAR) dosimetric cost improved on average across plans by [1.1%, 13.6%], and for photons, [0.6%, 2.0%]. Comparing algorithms, beam selection for PathGD was faster than GS-FISTA on average by 35%, and PathGD matched the CTV coverage of GS-FISTA plans while reducing OAR mean and maximum dose in all structures by an average of 13.6%. PathGD was able to improve CTV [Dmax, D95%] by [2.6%, 5.2%] and reduced worst-case [max, mean] dose in OARs by [11.1%, 13.1%].Significance. The benefit of a path-seeking algorithm is the beam-by-beam analysis of dosimetric cost. PathGD was shown to be most efficient and dosimetrically desirable amongst group sparsity and manual BOO methods, and highlights the sensitivity of beam addition for IMPT in particular.
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Affiliation(s)
- Pavitra Ramesh
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
| | - Gilmer Valdes
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, 94143, United States of America
| | - Daniel O'Connor
- Department of Mathematics and Statistics, University of San Francisco, San Francisco, CA, 94117, United States of America
| | - Ke Sheng
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, 94143, United States of America
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Church C, MacDonald RL, Parsons D, Syme A. Evaluation of plan quality and treatment efficiency in cranial stereotactic radiosurgery treatment plans with a variable source-to-axis distance. Med Phys 2023; 50:3039-3054. [PMID: 36774531 DOI: 10.1002/mp.16288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 10/03/2022] [Accepted: 01/31/2023] [Indexed: 02/13/2023] Open
Abstract
INTRODUCTION Radiotherapy deliveries with dynamic couch motions that shorten the source-to-axis distance (SAD) on a C-arm linac have the potential to increase treatment efficiency through the increase of the effective dose rate. In this investigation, we convert clinically deliverable volumetric modulated arc therapy (VMAT) and dynamic conformal arc (DCA) plans for cranial radiosurgery into virtual isocenter plans through implementation of couch trajectories that maintain the target at a shortened but variable SAD throughout treatment. MATERIALS AND METHODS A randomly sampled population of patients treated with cranial radiosurgery from within the last three years were separated into groups with one, two, and three lesions. All plans had a single isocenter (regardless of number of targets), and a single prescription dose. Patient treatment plans were converted from their original delivery at a standard isocenter to a dynamic virtual isocenter in MATLAB. The virtual isocenter plan featured a variable isocenter position based upon the closest achievable source-to-target distance (referred to herein as a virtual source-to-axis distance [vSAD]) which avoided collision zones on a TrueBeam STx platform. Apertures were magnified according to the vSAD and monitor units at a given control point were scaled based on the inverse square law. Doses were calculated for the plans with a virtual isocenter in the Eclipse (v13.6.23) treatment planning system (TPS) and were compared with the clinical plans. Plan metrics (MU, Paddick conformity index, gradient index, and the volume receiving 12 Gy or more), normal brain dose-volume differences, as well as maximum doses received by organs at risk (OARs) were assessed. The values were compared between standard and virtual isocenter plans with Wilcoxon Sign Ranked tests to determine significance. A subset of the plans were mapped to the MAX-HD anthropomorphic phantom which contained an insert housing EBT3 GafChromic film and a PTW 31010 microion chamber for dose verification on a linac. RESULTS Delivering plans at a virtual isocenter resulted in an average reduction of 20.9% (p = 3×10-6 ) and 20.6% (p = 3.0×10-6 ) of MUs across all VMAT and all DCA plans, respectively. There was no significant change in OAR max doses received by plans delivered at a virtual isocenter. The low dose wash (1.0-2.0 Gy or 5-11% of the prescription dose) was increased (by approximately 20 cc) for plans with three lesions. This was equivalent to a 2.7%-3.8% volumetric increase in normal tissue receiving the respective dose level when comparing the plan with a virtual isocenter to a plan with a standard isocenter. Gamma pass rates with a 5%/1mm analysis criteria were 96.40% ± 2.90% and 95.07% ± 3.10% for deliveries at standard and virtual isocenter, respectively. Absolute point dose agreements were within -0.36% ± 3.45% and -0.55% ± 3.39% for deliveries at a standard and virtual isocenter, respectively. Potential time savings per arc were found to have linear relationship with the monitor units delivered per arc (savings of 0.009 s/MU with an r2 = 0.866 when fit to plans with a single lesion). CONCLUSIONS Converting clinical plans at standard isocenter to a virtual isocenter design did not show any losses to plan quality while simultaneously improving treatment efficiency through MU reductions.
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Affiliation(s)
- Cody Church
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - R Lee MacDonald
- Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David Parsons
- Department of Radiation Oncology, University of Texas Southwestern Medical Centre, Dallas, Texas, USA
| | - Alasdair Syme
- Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
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Ma M, Niu C, Li M, Chen D, Yan L, Wang H, Dai J. Noncoplanar Volumetric Modulated Arc Therapy for Hepatocellular Carcinoma Based on a Cage-Like Radiotherapy System: A Simulation Study. Technol Cancer Res Treat 2023; 22:15330338231170495. [PMID: 37186800 DOI: 10.1177/15330338231170495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND The incorporation of noncoplanar beam arrangements has been proposed in liver radiotherapy modalities, which can reduce the dose in normal tissues compared to coplanar techniques. Noncoplanar radiotherapy techniques for hepatocellular carcinoma treatment based on the Linac design have a limited effective arc angle to avoid collisions. PURPOSE To propose a novel noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system and investigate its performance in hepatocellular carcinoma patients. METHODS The computed tomography was deflected 90° to meet the structure of a cage-like radiotherapy system and design the noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan in the Pinnacle3 planning system. An noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan was customized for each of 10 included hepatocellular carcinoma patients, with 6 dual arcs ranging from -30° to 30°. Six couch angles were set with an interval of 36° and distributed along with the longest diameter of planning target volume. The dosimetric parameters of noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan were compared with the noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy plan. RESULTS The 3 radiotherapy techniques regarding planning target volume were statistically different for D98%, D2%, conformity index, and homogeneity index with χ2 = 9.692, 14.600, 8.600, and 12.600, and P = .008, .001, .014, and .002, respectively. Further multiple comparisons revealed that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .005) of the stomach, and V30 (P = .028) of the lung compared to noncoplanar volumetric modulated arc therapy. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .017) of the spinal cord, V50 (P = .043) of the duodenum, the maximum dose (P = .007) of the esophagus, and V30 (P = .047) of the whole lung compared to volumetric modulated arc therapy. The results indicate that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system protects the normal liver, stomach, and lung better than noncoplanar volumetric modulated arc therapy and protects the normal liver, spinal cord, duodenum, esophagus, and lung better than volumetric modulated arc therapy. CONCLUSIONS The noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system technique with the arrangement of noncoplanar arcs provided optimal dosimetric gains compared with noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy, except for the heart. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system should be considered in more clinically challenging cases.
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Affiliation(s)
- Min Ma
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chuanmeng Niu
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Minghui Li
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Deqi Chen
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lingling Yan
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hongkai Wang
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianrong Dai
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Jiang L, Lyu Q, Abdelhamid AMH, Hui S, Sheng K. An efficient rectangular optimization method for sparse orthogonal collimator based small animal irradiation. Phys Med Biol 2022; 67:10.1088/1361-6560/ac910b. [PMID: 36084625 PMCID: PMC9595432 DOI: 10.1088/1361-6560/ac910b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/09/2022] [Indexed: 11/11/2022]
Abstract
Objective.Intensity-modulated radiotherapy (IMRT) is widely used in clinical radiotherapy, treating varying malignancies with conformal doses. As the test field for clinical translation, preclinical small animal experiments need to mimic the human radiotherapy condition, including IMRT. However, small animal IMRT is a systematic challenge due to the lack of corresponding hardware and software for miniaturized targets.Approach.The sparse orthogonal collimators (SOC) based on the direct rectangular aperture optimization (RAO) substantially simplified the hardware for miniaturization. This study investigates and evaluates a significantly improved RAO algorithm for complex mouse irradiation using SOC. Because the Kronecker product representation of the rectangular aperture is the main limitation of the computational performance, we reformulated matrix multiplication in the data fidelity term using multiplication with small matrices instead of the Kronecker product of the dose loading matrices. Solving the optimization problem was further accelerated using the Fast Iterative Shrinkage-Thresholding Algorithm (FISTA).Main results.Four mouse cases, including a liver, a brain tumor, a concave U-target, and a complex total marrow irradiation (TMI) case, were included in this study with manually delineated targets and OARs. Seven coplanar-field SOC IMRT (sIMRT) plans were compared with idealistic fluence map based IMRT (iIMRT) plans. For the first three cases with simpler and smaller targets, the differences between sIMRT plans and iIMRT plans in the planning target volumes (PTV) statistics are within 1%. For the TMI case, the sIMRT plans are superior in reducing hot spots (also termedDmax) of PTV, kidneys, lungs, heart, and bowel by 20.5%, 31.5%, 24.67%, 20.13%, and 17.78%, respectively. On average, in four cases in this study, the sIMRT plan conformity is comparable to that of the iIMRT's with lightly increased R50 and Integral Dose by 2.23% and 2.78%.Significance.The significantly improved sIMRT optimization method allows fast plan creation in under 1 min for smaller targets and makes complex TMI planning feasible while achieving comparable dosimetry to idealistic IMRT with fluence map optimization.
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Affiliation(s)
- Lu Jiang
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Amr M H Abdelhamid
- Department of Radiation Oncology, City of Hope Medical Center, Duarte, CA, United States of America
| | - Susanta Hui
- Department of Radiation Oncology, City of Hope Medical Center, Duarte, CA, United States of America
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, United States of America
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Guyer G, Mueller S, Koechli C, Frei D, Volken W, Bertholet J, Mackeprang PH, Loebner HA, Aebersold DM, Manser P, Fix MK. Enabling non-isocentric dynamic trajectory radiotherapy by integration of dynamic table translations. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac840d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 07/25/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The purpose of this study is to develop a treatment planning process (TPP) for non-isocentric dynamic trajectory radiotherapy (DTRT) using dynamic gantry rotation, collimator rotation, table rotation, longitudinal, vertical and lateral table translations and intensity modulation and to validate the dosimetric accuracy. Approach. The TPP consists of two steps. First, a path describing the dynamic gantry rotation, collimator rotation and dynamic table rotation and translations is determined. Second, an optimization of the intensity modulation along the path is performed. We demonstrate the TPP for three use cases. First, a non-isocentric DTRT plan for a brain case is compared to an isocentric DTRT plan in terms of dosimetric plan quality and delivery time. Second, a non-isocentric DTRT plan for a craniospinal irradiation (CSI) case is compared to a multi-isocentric intensity modulated radiotherapy (IMRT) plan. Third, a non-isocentric DTRT plan for a bilateral breast case is compared to a multi-isocentric volumetric modulated arc therapy (VMAT) plan. The non-isocentric DTRT plans are delivered on a TrueBeam in developer mode and their dosimetric accuracy is validated using radiochromic films. Main results. The non-isocentric DTRT plan for the brain case is similar in dosimetric plan quality and delivery time to the isocentric DTRT plan but is expected to reduce the risk of collisions. The DTRT plan for the CSI case shows similar dosimetric plan quality while reducing the delivery time by 45% in comparison with the IMRT plan. The DTRT plan for the breast case showed better treatment plan quality in comparison with the VMAT plan. The gamma passing rates between the measured and calculated dose distributions are higher than 95% for all three plans. Significance. The versatile benefits of non-isocentric DTRT are demonstrated with three use cases, namely reduction of collision risk, reduced setup and delivery time and improved dosimetric plan quality.
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Okoli F, Bert J, Abdelaziz S, Boussion N, Visvikis D. Optimizing the Beam Selection for Noncoplanar VMAT by Using Simulated Annealing Approach. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022. [DOI: 10.1109/trpms.2021.3111736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pokhrel D, Bernard ME, Johnson J, Fabian D, Kudrimoti M. HyperArc VMAT stereotactic radiotherapy for locally recurrent previously‐irradiated head and neck cancers: Plan quality, treatment delivery accuracy, and efficiency. J Appl Clin Med Phys 2022; 23:e13561. [PMID: 35253992 PMCID: PMC9121031 DOI: 10.1002/acm2.13561] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 01/20/2022] [Accepted: 02/02/2022] [Indexed: 11/10/2022] Open
Abstract
Purpose Materials/Methods Results Conclusion
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Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate Program Department of Radiation Medicine University of Kentucky Lexington Kentucky USA
| | - Mark E Bernard
- Medical Physics Graduate Program Department of Radiation Medicine University of Kentucky Lexington Kentucky USA
| | - Jeremiah Johnson
- Medical Physics Graduate Program Department of Radiation Medicine University of Kentucky Lexington Kentucky USA
| | - Denise Fabian
- Medical Physics Graduate Program Department of Radiation Medicine University of Kentucky Lexington Kentucky USA
| | - Mahesh Kudrimoti
- Medical Physics Graduate Program Department of Radiation Medicine University of Kentucky Lexington Kentucky USA
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Q. M. Reis C, Little B, Lee MacDonald R, Syme A, Thomas CG, Robar JL. SBRT of ventricular tachycardia using 4pi optimized trajectories. J Appl Clin Med Phys 2021; 22:72-86. [PMID: 34679247 PMCID: PMC8664144 DOI: 10.1002/acm2.13454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/05/2021] [Accepted: 10/03/2021] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To investigate the possible advantages of using 4pi-optimized arc trajectories in stereotactic body radiation therapy of ventricular tachycardia (VT-SBRT) to minimize exposure of healthy tissues. METHODS AND MATERIALS Thorax computed tomography (CT) data for 15 patients were used for contouring organs at risk (OARs) and defining realistic planning target volumes (PTVs). A conventional trajectory plan, defined as two full coplanar arcs was compared to an optimized-trajectory plan provided by a 4pi algorithm that penalizes geometric overlap of PTV and OARs in the beam's-eye-view. A single fraction of 25 Gy was prescribed to the PTV in both plans and a comparison of dose sparing to OARs was performed based on comparisons of maximum, mean, and median dose. RESULTS A significant average reduction in maximum dose was observed for esophagus (18%), spinal cord (26%), and trachea (22%) when using 4pi-optimized trajectories. Mean doses were also found to decrease for esophagus (19%), spinal cord (33%), skin (18%), liver (59%), lungs (19%), trachea (43%), aorta (11%), inferior vena cava (25%), superior vena cava (33%), and pulmonary trunk (26%). A median dose reduction was observed for esophagus (40%), spinal cord (48%), skin (36%), liver (72%), lungs (41%), stomach (45%), trachea (53%), aorta (45%), superior vena cava (38%), pulmonary veins (32%), and pulmonary trunk (39%). No significant difference was observed for maximum dose (p = 0.650) and homogeneity index (p = 0.156) for the PTV. Average values of conformity number were 0.86 ± 0.05 and 0.77 ± 0.09 for the conventional and 4pi optimized plans respectively. CONCLUSIONS 4pi optimized trajectories provided significant reduction to mean and median doses to cardiac structures close to the target but did not decrease maximum dose. Significant improvement in maximum, mean and median doses for noncardiac OARs makes 4pi optimized trajectories a suitable delivery technique for treating VT.
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Affiliation(s)
- Cristiano Q. M. Reis
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Radiation Oncology, London Regional Cancer ProgramLondon Health Sciences Centre790 Commissioners Road EastLondonONN6A 4L6Canada
| | - Brian Little
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
- Adaptiiv Medical Technologies Inc405‐1344 Summer Street Halifax, NS B3H 0A8Canada
| | - Robert Lee MacDonald
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
| | - Alasdair Syme
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
- Beatrice Hunter Cancer Research InstituteHalifaxNova ScotiaCanada
| | - Christopher G. Thomas
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
- Beatrice Hunter Cancer Research InstituteHalifaxNova ScotiaCanada
- Department of RadiologyDalhousie UniversityHalifaxNova ScotiaCanada
| | - James L. Robar
- Department of Radiation OncologyDalhousie UniversityHalifaxNova ScotiaCanada
- Department of Medical PhysicsScotia Health Authority, NovaHalifaxNova ScotiaCanada
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNova ScotiaCanada
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Kafaei P, Cappart Q, Renaud MA, Chapados N, Rousseau LM. Graph neural networks and deep reinforcement learning for simultaneous beam orientation and trajectory optimization of Cyberknife. Phys Med Biol 2021; 66. [PMID: 34592726 DOI: 10.1088/1361-6560/ac2bb5] [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: 05/05/2021] [Accepted: 09/30/2021] [Indexed: 11/12/2022]
Abstract
Objective. Despite the high-quality treatment, the long treatment time of the Cyberknife system is believed to be a drawback. The high flexibility of its robotic arm requires meticulous path-finding algorithms to deliver the prescribed dose in the shortest time.Approach. We proposed a Deep Q-learning based on Graph Neural Networks to find the subset of the beams and the order to traverse them. A complex reward function is defined to minimize the distance covered by the robotic arm while avoiding the selection of close beams. Individual beam scores are also generated based on their effect on the beam intensity and are incorporated in the reward function. Main results. The performance of the presented method is evaluated on three clinical cases suffering from lung cancer. Applying this approach leads to an average of 35% reduction in the treatment time while delivering the prescribed dose provided by the physicians.Significance. Shorter treatment times result in a better treatment experience for individual patients, reduces discomfort and the sides effects of inadvertent movements for them. Additionally, it creates the opportunity to treat a higher number of patients in a given time period at the radiation therapy centers.
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Affiliation(s)
- Peyman Kafaei
- Department of Mathematics and Industrial Engineering, Polytechnique Montreal, Montreal, Canada.,CIRRELT-Interuniversity Research Center on Enterprise Networks, Logistics and Transportation, Montreal, Canada
| | - Quentin Cappart
- CIRRELT-Interuniversity Research Center on Enterprise Networks, Logistics and Transportation, Montreal, Canada.,Department of Computer Engineering and Software Engineering, Polytechnique Montreal, Montreal, Canada
| | - Marc-Andre Renaud
- Department of Mathematics and Industrial Engineering, Polytechnique Montreal, Montreal, Canada.,CIRRELT-Interuniversity Research Center on Enterprise Networks, Logistics and Transportation, Montreal, Canada
| | - Nicolas Chapados
- Department of Mathematics and Industrial Engineering, Polytechnique Montreal, Montreal, Canada
| | - Louis-Martin Rousseau
- Department of Mathematics and Industrial Engineering, Polytechnique Montreal, Montreal, Canada.,CIRRELT-Interuniversity Research Center on Enterprise Networks, Logistics and Transportation, Montreal, Canada
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Ventura T, Rocha H, da Costa Ferreira B, Dias J, do Carmo Lopes M. Comparison of non-coplanar optimization of static beams and arc trajectories for intensity-modulated treatments of meningioma cases. Phys Eng Sci Med 2021; 44:1273-1283. [PMID: 34618329 PMCID: PMC8668856 DOI: 10.1007/s13246-021-01061-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 09/24/2021] [Indexed: 11/30/2022]
Abstract
Two methods for non-coplanar beam direction optimization, one for static beams and another for arc trajectories, were proposed for intracranial tumours. The results of the beam angle optimizations were compared with the beam directions used in the clinical plans. Ten meningioma cases already treated were selected for this retrospective planning study. Algorithms for non-coplanar beam angle optimization (BAO) and arc trajectory optimization (ATO) were used to generate the corresponding plans. A plan quality score, calculated by a graphical method for plan assessment and comparison, was used to guide the beam angle optimization process. For each patient, the clinical plans (CLIN), created with the static beam orientations used for treatment, and coplanar VMAT approximated plans (VMAT) were also generated. To make fair plan comparisons, all plan optimizations were performed in an automated multicriteria calculation engine and the dosimetric plan quality was assessed. BAO and ATO plans presented, on average, moderate global plan score improvements over VMAT and CLIN plans. Nevertheless, while BAO and CLIN plans assured a more efficient OARs sparing, the ATO and VMAT plans presented a higher coverage and conformity of the PTV. Globally, all plans presented high-quality dose distributions. No statistically significant quality differences were found, on average, between BAO, ATO and CLIN plans. However, automated plan solution optimizations (BAO or ATO) may improve plan generation efficiency and standardization. In some individual patients, plan quality improvements were achieved with ATO plans, demonstrating the possible benefits of this automated optimized delivery technique.
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Affiliation(s)
- Tiago Ventura
- Physics Department of University of Aveiro, Aveiro, Portugal.
- Medical Physics Department of the Portuguese Oncology Institute of Coimbra Francisco Gentil, EPE, Coimbra, Portugal.
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.
| | - Humberto Rocha
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Brigida da Costa Ferreira
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
- I3N Physics Department of University of Aveiro, Aveiro, Portugal
| | - Joana Dias
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Maria do Carmo Lopes
- Medical Physics Department of the Portuguese Oncology Institute of Coimbra Francisco Gentil, EPE, Coimbra, Portugal
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- I3N Physics Department of University of Aveiro, Aveiro, Portugal
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12
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Huang C, Yang Y, Xing L. Fully automated noncoplanar radiation therapy treatment planning. Med Phys 2021; 48:7439-7449. [PMID: 34519064 DOI: 10.1002/mp.15223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To perform fully automated noncoplanar (NC) treatment planning, we propose a method called NC-POPS to produce NC plans using the Pareto optimal projection search (POPS) algorithm. METHODS NC radiation therapy treatment planning has the potential to improve dosimetric quality as compared to traditional coplanar techniques. Likewise, automated treatment planning algorithms can reduce a planner's active treatment planning time and remove inter-planner variability. Our NC-POPS algorithm extends the original POPS algorithm to the NC setting with potential applications to both intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). The proposed algorithm consists of two main parts: (1) NC beam angle optimization (BAO) and (2) fully automated inverse planning using the POPS algorithm. RESULTS We evaluate the performance of NC-POPS by comparing between various NC and coplanar configurations. To evaluate plan quality, we compute the homogeneity index (HI), conformity index (CI), and dose-volume histogram statistics for various organs-at-risk (OARs). As compared to the evaluated coplanar baseline methods, the proposed NC-POPS method achieves significantly better OAR sparing, comparable or better dose conformity, and similar dose homogeneity. CONCLUSIONS Our proposed NC-POPS algorithm provides a modular approach for fully automated treatment planning of NC IMRT cases with the potential to substantially improve treatment planning workflow and plan quality.
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Affiliation(s)
- Charles Huang
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Yong Yang
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
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13
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Woods K, Chin RK, Cook KA, Sheng K, Kishan AU, Hegde JV, Tenn S, Steinberg ML, Cao M. Automated Non-Coplanar VMAT for Dose Escalation in Recurrent Head and Neck Cancer Patients. Cancers (Basel) 2021; 13:cancers13081910. [PMID: 33921062 PMCID: PMC8071369 DOI: 10.3390/cancers13081910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/05/2021] [Accepted: 04/12/2021] [Indexed: 11/29/2022] Open
Abstract
Simple Summary The ability to escalate the radiation dose to head and neck tumors has been shown to offer improved local control, and consequently, survival for recurrent head and neck cancer (rHNC) patients. This study evaluates the HyperArc automated non-coplanar planning technique (originally developed for intracranial treatment) for 20 rHNC patients, and compares this technique to conventional planning methods. HyperArc enables significant tumor dose escalation, with average increases in mean target dose of over 11.5 Gy (26%), while maintaining clinically-equivalent doses to nearby organs. Our results show that the average probability of tumor control is 23% higher for HyperArc than conventional techniques. Abstract This study evaluates the potential for tumor dose escalation in recurrent head and neck cancer (rHNC) patients with automated non-coplanar volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) planning (HyperArc). Twenty rHNC patients are planned with conventional VMAT SBRT to 40 Gy while minimizing organ-at-risk (OAR) doses. They are then re-planned with the HyperArc technique to match these minimal OAR doses while escalating the target dose as high as possible. Then, we compare the dosimetry, tumor control probability (TCP), and normal tissue complication probability (NTCP) for the two plan types. Our results show that the HyperArc technique significantly increases the mean planning target volume (PTV) and gross tumor volume (GTV) doses by 10.8 ± 4.4 Gy (25%) and 11.5 ± 5.1 Gy (26%) on average, respectively. There are no clinically significant differences in OAR doses, with maximum dose differences of <2 Gy on average. The average TCP is 23% (± 21%) higher for HyperArc than conventional plans, with no significant differences in NTCP for the brainstem, cord, mandible, or larynx. HyperArc can achieve significant tumor dose escalation while maintaining minimal OAR doses in the head and neck—potentially enabling improved local control for rHNC SBRT patients without increased risk of treatment-related toxicities.
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Affiliation(s)
- Kaley Woods
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Robert K. Chin
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Kiri A. Cook
- Department of Radiation Oncology, Oregon Health & Science University, Portland, OR 97239, USA;
| | - Ke Sheng
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Amar U. Kishan
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - John V. Hegde
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Stephen Tenn
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Michael L. Steinberg
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
| | - Minsong Cao
- Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA; (K.W.); (R.K.C.); (K.S.); (A.U.K.); (J.V.H.); (S.T.); (M.L.S.)
- Correspondence:
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14
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Sharfo AWM, Rossi L, Dirkx MLP, Breedveld S, Aluwini S, Heijmen BJM. Complementing Prostate SBRT VMAT With a Two-Beam Non-Coplanar IMRT Class Solution to Enhance Rectum and Bladder Sparing With Minimum Increase in Treatment Time. Front Oncol 2021; 11:620978. [PMID: 33816253 PMCID: PMC8018286 DOI: 10.3389/fonc.2021.620978] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 03/01/2021] [Indexed: 01/05/2023] Open
Abstract
Purpose Enhance rectum and bladder sparing in prostate SBRT with minimum increase in treatment time by complementing dual-arc coplanar VMAT with a two-beam non-coplanar IMRT class solution (CS). Methods For twenty patients, an optimizer for automated multi-criterial planning with integrated beam angle optimization (BAO) was used to generate dual-arc VMAT plans, supplemented with five non-coplanar IMRT beams with individually optimized orientations (VMAT+5). In all plan generations, reduction of high rectum dose had the highest priority after obtaining adequate PTV coverage. A CS with two most preferred directions in VMAT+5 and largest rectum dose reductions compared to dual-arc VMAT was then selected to define VMAT+CS. VMAT+CS was compared with automatically generated i) dual-arc coplanar VMAT plans (VMAT), ii) VMAT+5 plans, and iii) IMRT plans with 30 patient-specific non-coplanar beam orientations (30-NCP). Plans were generated for a 4 x 9.5 Gy fractionation scheme. Differences in PTV doses, healthy tissue sparing, and computation and treatment delivery times were quantified. Results For equal PTV coverage, VMAT+CS, consisting of dual-arc VMAT supplemented with two fixed, non-coplanar IMRT beams with fixed Gantry/Couch angles of 65°/30° and 295°/-30°, significantly reduced OAR doses and the dose bath, compared to dual-arc VMAT. Mean relative differences in rectum Dmean, D1cc, V40GyEq and V60GyEq were 19.4 ± 10.6%, 4.2 ± 2.7%, 34.9 ± 20.3%, and 39.7 ± 23.2%, respectively (all p<0.001). There was no difference in bladder D1cc, while bladder Dmean reduced by 17.9 ± 11.0% (p<0.001). Also, the clinically evaluated urethra D5%, D10%, and D50% showed small, but statistically significant improvements. All patient VX with X = 2, 5, 10, 20, and 30 Gy were reduced with VMAT+CS, with a maximum relative reduction for V10Gy of 19.0 ± 7.3% (p<0.001). Total delivery times with VMAT+CS only increased by 1.9 ± 0.7 min compared to VMAT (9.1 ± 0.7 min). The dosimetric quality of VMAT+CS plans was equivalent to VMAT+5, while optimization times were reduced by a factor of 25 due to avoidance of individualized BAO. Compared to VMAT+CS, the 30-NCP plans were only favorable in terms of dose bath, at the cost of much enhanced optimization and delivery times. Conclusions The proposed two-beam non-coplanar class solution to complement coplanar dual-arc VMAT resulted in substantial plan quality improvements for OARs (especially rectum) and reduced irradiated patient volumes with minor increases in treatment delivery times.
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Affiliation(s)
- Abdul Wahab M Sharfo
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, Netherlands
| | - Linda Rossi
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, Netherlands
| | - Maarten L P Dirkx
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, Netherlands
| | - Sebastiaan Breedveld
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, Netherlands
| | - Shafak Aluwini
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, Netherlands
| | - Ben J M Heijmen
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, Netherlands
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15
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Lyu Q, Neph R, O'Connor D, Ruan D, Boucher S, Sheng K. ROAD: ROtational direct Aperture optimization with a Decoupled ring-collimator for FLASH radiotherapy. Phys Med Biol 2021; 66:035020. [PMID: 33207321 DOI: 10.1088/1361-6560/abcbd0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ultra-high dose rate in radiotherapy (FLASH) has been shown to increase the therapeutic index with markedly reduced normal tissue toxicity and the same or better tumor cell killing. The challenge to achieve FLASH using x-rays, besides developing a high output linac, is to intensity-modulate the high-dose-rate x-rays so that the biological gain is not offset by the lack of physical dose conformity. In this study, we develop the ROtational direct Aperture optimization with a Decoupled ring-collimator (ROAD) to achieve simultaneous ultrafast delivery and complex dose modulation. The ROAD design includes a fast-rotating slip-ring linac and a decoupled collimator-ring with 75 pre-shaped multi-leaf-collimator (MLC) modules. The ring-source rotates at 1 rotation per second (rps) clockwise while the ring-collimator is either static or rotating at 1 rps counterclockwise, achieving 75 (ROAD-75) or 150 (ROAD-150) equal-angular beams for one full arc. The Direct Aperture Optimization (DAO) for ROAD was formulated to include a least-square dose fidelity, an anisotropic total variation term, and a single segment term. The FLASH dose (FD) and FLASH biological equivalent dose (FBED) were computed voxelwise, with the latter using a spatiotemporal model accounting for radiolytic oxygen depletion. ROAD was compared with clinical volumetric modulated arc therapy (VMAT) on a brain, a lung, a prostate, and a head and neck cancer patient. The mean dose rate of ROAD-75 and ROAD-150 are 76.2 Gy s-1 and 112 Gy s-1 respectively to deliver 25 Gy single-fraction dose in 1 s. With improved PTV homogeneity, ROAD-150 reduced (max, mean) OAR physical dose by (4.8 Gy, 6.3 Gy). The average R50 and integral dose of (VMAT, ROAD-75, ROAD-150) are (4.8, 3.2, 3.2) and (89, 57, 56) Gy×Liter, respectively. The FD and FBED showed model dependent FLASH effects. The novel ROAD design achieves ultrafast dose delivery and improves physical dosimetry compared with clinical VMAT, providing a potentially viable engineering solution for x-ray FLASH radiotherapy.
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Affiliation(s)
- Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
| | - Ryan Neph
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
| | - Daniel O'Connor
- Department of Mathematics and Statistics, University of San Francisco, San Francisco, CA 94143, United States of America
| | - Dan Ruan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
| | - Salime Boucher
- RadiaBeam Technologies, Santa Monica, CA 90404, United States of America
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
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16
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Neph R, Lyu Q, Huang Y, Yang YM, Sheng K. DeepMC: a deep learning method for efficient Monte Carlo beamlet dose calculation by predictive denoising in magnetic resonance-guided radiotherapy. Phys Med Biol 2021; 66:035022. [PMID: 33181498 PMCID: PMC9845197 DOI: 10.1088/1361-6560/abca01] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Emerging magnetic resonance (MR) guided radiotherapy affords significantly improved anatomy visualization and, subsequently, more effective personalized treatment. The new therapy paradigm imposes significant demands on radiation dose calculation quality and speed, creating an unmet need for the acceleration of Monte Carlo (MC) dose calculation. Existing deep learning approaches to denoise the final plan MC dose fail to achieve the accuracy and speed requirements of large-scale beamlet dose calculation in the presence of a strong magnetic field for online adaptive radiotherapy planning. Our deep learning dose calculation method, DeepMC, addresses these needs by predicting low-noise dose from extremely noisy (but fast) MC-simulated dose and anatomical inputs, thus enabling significant acceleration. DeepMC simultaneously reduces MC sampling noise and predicts corrupted dose buildup at tissue-air material interfaces resulting from MR-field induced electron return effects. Here we demonstrate our model's ability to accelerate dose calculation for daily treatment planning by a factor of 38 over traditional low-noise MC simulation with clinically meaningful accuracy in deliverable dose and treatment delivery parameters. As a post-processing approach, DeepMC provides compounded acceleration of large-scale dose calculation when used alongside established MC acceleration techniques in variance reduction and graphics processing unit-based MC simulation.
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Affiliation(s)
- Ryan Neph
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California 90095
| | - Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California 90095
| | | | - You Ming Yang
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California 90095
| | - Ke Sheng
- Corresponding Author: All communications may be addressed to Ke Sheng at or by mail at: 200 Medical Plaza #B265, University of California, c/o Ke Sheng, Los Angeles, California 90095
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Mullins J, Renaud MA, Serban M, Seuntjens J. Simultaneous trajectory generation and volumetric modulated arc therapy optimization. Med Phys 2020; 47:3078-3090. [PMID: 32215936 DOI: 10.1002/mp.14155] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Trajectory-based treatment planning involves the combination of a gantry-couch trajectory with volumetric modulated arc therapy (VMAT) treatment plan optimization. This work presents the implementation of an optimization methodology that generates a trajectory simultaneous with treatment plan optimization (simTr-VMAT). METHODS The optimization algorithm is based on the column generation approach, in which a treatment plan is iteratively constructed through the solution of a subproblem called the "pricing problem." The property of the pricing problem to rank candidate apertures based on their associated price is leveraged to select an optimal aperture while simultaneously determining the trajectory path. A progressively increasing gantry-couch grid resolution is used to provide an initial coarse sampling of the angular solution space while maintaining fine control point spacing with the final treatment plan. The trajectory optimization was applied and compared to coplanar VMAT treatment plans for a lung patient, a glioblastoma patient, and a prostate patient. Algorithm validation was performed through the generation of 5000 random trajectories and optimization using column generation VMAT for each patient case, representing the solution space for the trajectory optimization problem. The simTr-VMAT trajectories were compared against these random trajectories based on a quality metric that prefers trajectories with few control points and low objective function value over long, inefficient trajectories. RESULTS For the lung patient, the simTr-VMAT plan resulted in a decrease of the mean dose of 1.5 and 1.0 Gy to the heart and ipsilateral lung, respectively. For the glioblastoma patient, the simTr-VMAT plan resulted in improved planning target volume coverage with a decrease in mean dose to the eyes, lens, nose, and contralateral temporal lobe between 2 and 7 Gy. The prostate patient showed no clinically relevant dosimetric improvement. The simTr-VMAT treatment plans ranked at the 99.6, 96.3, and 99.4 percentiles compared to the distribution of randomly generated trajectories for the lung, glioblastoma, and prostate patients, respectively. CONCLUSION The simTr-VMAT optimization methodology resulted in treatment plans with equivalent or improved dosimetric outcomes compared to coplanar VMAT treatment plans, with the trajectories resulting from the optimization ranking among the optimal trajectories for each patient case.
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Affiliation(s)
- Joel Mullins
- Department of Physics & Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Marc-André Renaud
- Department of Mathematics and Industrial Engineering, Polytechnique Montréal, Montréal, QC, H3T 1J4, Canada
| | - Monica Serban
- Medical Physics Unit, McGill University Health Centre, Montréal, QC, H4A 3J1, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University & Research Institute of the McGill University Health Centre, Montréal, QC, H4A 3J1, Canada
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18
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Mullins J, Renaud MA, Heng V, Ruo R, DeBlois F, Seuntjens J. Trajectory-based VMAT for cranial targets with delivery at shortened SAD. Med Phys 2020; 47:3103-3112. [PMID: 32198933 DOI: 10.1002/mp.14151] [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: 10/16/2019] [Revised: 03/04/2020] [Accepted: 03/07/2020] [Indexed: 01/17/2023] Open
Abstract
INTRODUCTION Trajectory-based volumetric modulated arc therapy (tr-VMAT) treatment plans enable the option for noncoplanar delivery yielding steeper dose gradients and increased sparing of critical structures compared to conventional treatment plans. The addition of translational couch motion to shorten the effective source-to-axis distance (SAD) may result in improved delivery precision and an increased effective dose rate. In this work, tr-VMAT treatment plans using a noncoplanar "baseball stitch" trajectory were implemented, applied to patients presented with cranial targets, and compared to the clinical treatment plans. METHODS A treatment planning workflow was implemented: (a) beamlet doses were calculated for control points defined along a baseball stitch trajectory using a collapsed-cone convolution-superposition algorithm; (b) VMAT treatment plans were optimized using the column generation approach; (c) a final dose distribution was calculated in Varian Eclipse using the analytical anisotropic algorithm by importing the optimized treatment plan parameters. Tr-VMAT plans were optimized for ten patients presented with cranial targets at both standard and shortened SAD, and compared to the clinical treatment plans through isodose distributions, dose-volume histograms, and dosimetric indices. The control point specifications of the optimized tr-VMAT plans were used to estimate the delivery time. RESULTS The optimized tr-VMAT plans with both shortened and standard SAD delivery yielded a comparable plan quality to the clinical treatment plans. A statistically significant benefit was observed for dose gradient index and monitor unit efficiency for shortened SAD tr-VMAT plans, while improved target volume conformity was observed for the clinical treatment plan (P ≤ 0.05). A clear dosimetric benefit was not demonstrated between tr-VMAT delivery at shortened SAD compared to standard SAD, but shortened SAD delivery yielded a fraction size-dependent reduction in the estimated delivery time. CONCLUSION The implementation of "baseball stitch" tr-VMAT treatment plans to patients presented with cranial targets demonstrated comparable plan quality to clinical treatment plans. The delivery at shortened SAD produced a fraction size-dependent decrease in estimated delivery time.
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Affiliation(s)
- Joel Mullins
- Department of Physics & Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Marc-André Renaud
- Department of Mathematics and Industrial Engineering, Polytechnique Montréal, Montréal, QC, H3T 1J4, Canada
| | - Veng Heng
- Department of Physics & Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Russell Ruo
- Medical Physics Unit, McGill University Health Centre, Montréal, QC, H4A 3J1, Canada
| | - François DeBlois
- Centre Hospitalier de l'Université de Montréal & Département de Physique, Université de Montréal, Montréal, QC, H2X 3E4, Canada.,McGill University, Montréal, QC, H4A 3J1, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University & Research Institute of the McGill University Health Centre, Montréal, QC, H4A 3J1, Canada
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Lyu Q, Neph R, Yu VY, Ruan D, Boucher S, Sheng K. Many-isocenter optimization for robotic radiotherapy. Phys Med Biol 2020; 65:045003. [PMID: 31851958 PMCID: PMC7100370 DOI: 10.1088/1361-6560/ab63b8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite significant dosimetric gains, clinical implementation of the 4π non-coplanar radiotherapy on the widely available C-arm gantry system is hindered by limited clearance, and the need to perform complex coordinated gantry and couch motion. A robotic radiotherapy platform would be conducive to such treatment but a new conflict between field size and MLC modulation resolution needs to be managed for versatile applications. This study investigates the dosimetry and delivery efficiency of purposefully creating many isocenters to achieve simultaneously high MLC modulation resolution and large tumor coverage. An integrated optimization framework was proposed for simultaneous beam orientation optimization (BOO), isocenter selection, and fluence map optimization (FMO). The framework includes a least-square dose fidelity objective, a total variation term for regularizing the fluence smoothness, and a group sparsity term for beam selection. A minimal number of isocenters were identified for efficient target coverage. Colliding beams excluded, high-resolution small-field 4π intensity-modulated radiotherapy (IMRT) treatment plans with 50 cm source-to-isocenter distance (SID-50) on 10 Head and Neck (H&N) cancer patients were compared with low-resolution large-field plans with 100 cm SID (SID-100). With the same or better target coverage, the average reduction of [Dmean, Dmax] of 20-beam SID-50 plans from 20-beam SID-100 plans were [2.09 Gy, 1.19 Gy] for organs at risk (OARs) overall, [3.05 Gy, 0.04 Gy] for parotid gland, [3.62 Gy, 5.19 Gy] for larynx, and [3.27 Gy, 1.10 Gy] for mandible. R50 and integral dose were reduced by 5.3% and 9.6%, respectively. Wilcoxon signed-rank test showed significant difference (p < 0.05) in planning target volume (PTV) homogeneity, PTV Dmax, R50, Integral dose, and OAR Dmean and Dmax. The estimated delivery time of 20-beam [SID-50, SID-100] plans were [19, 18] min and [14, 9] min, assuming 5 fractions and 30 fractions, respectively. With clinically acceptable delivery efficiency, many-isocenter optimization is dosimetrically desirable for treating large targets with high modulation resolution on the robotic platform.
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Affiliation(s)
- Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, United States of America
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MacDonald RL, Syme A, Little B, Ward L, Thomas CG. Toward the combined optimization of dynamic axes (CODA) for stereotactic radiotherapy and radiosurgery using fixed couch trajectories. Med Phys 2019; 47:307-316. [PMID: 31659750 DOI: 10.1002/mp.13887] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To develop a novel system for patient-specific combined optimization of couch, collimator, and gantry angles for use in volumetric modulated arc therapy (VMAT) treatment planning. The system was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch trajectory planning was used to reduce normal tissue doses by avoiding beams-eye-view (BEV) overlap with organs-at-risk (OARs) and improve monitor unit (MU) efficiency through collimator angle optimization. METHODS By merging distinct BEV objective functions used to optimize the couch rotation angle and collimator angle, a three-dimensional (3D) cost space (the CODA cube) was constructed with axes of gantry, couch, and collimator rotation angles. At each voxel in this CODA cube, the cost of implementing this combination of axes positions in fixed couch trajectories was quantified. The CODA cube was sampled and explored using a modified constrained Bellman-Ford algorithm to suggest low-cost fixed candidate arcs on each plane of the space, from which 10-arcs are chosen throughout the 3D space using a k-means clustering algorithm. These fixed couch trajectories were then imported into the Eclipse treatment planning system (v.11) and inverse-optimized according to clinical standards. Eight artificial cranial targets were contoured in a test-patient anatomy, and seven treatment plans were generated from combinations of three and four targets. The CODA cube optimized plans were compared to standard 4-arc VMAT plans for cranial stereotactic radiotherapy/surgery that were optimized for the same sets of targets; maximum dose to each OAR, V12Gy to normal brain, conformity, and total MUs were compared. Both planning methods were inverse-optimized with identical dosimetric objectives. RESULTS CODA plans resulted in a reduction in maximum dose to OARs of 20.6% (P < 0.01), with maximum brainstem dose decreased by 2.63 Gy (P = 0.031) on average when compared to the standard arc arrangement. The mean reduction in total MU was 8.6% (P = 0.156), the mean increase in the inverse of the van't Riet conformation number was 0.1%, (P = 0.67) and the mean decrease in normal brain tissue receiving 12 Gy or higher was 3.9% (P = 0.16), when compared to the standard VMAT arc configuration (n = 7). CONCLUSIONS The optimization of couch, collimator, and gantry angles simultaneously using a 3D optimization space achieved improvement on multiple clinical metrics when compared to the standard VMAT arc configuration. A statistically significant sparing to OAR maximum doses was seen. Combining these optimizations may yield superior results to independent optimization.
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Affiliation(s)
- R Lee MacDonald
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Alasdair Syme
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4J5, Canada.,Department of Medical Physics, Nova Scotia Health Authority, Queen Elizabeth II Health Sciences Centre, Halifax, NS, B3H 1V7, Canada.,Department of Radiation Oncology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Brian Little
- Department of Medical Physics, Nova Scotia Health Authority, Queen Elizabeth II Health Sciences Centre, Halifax, NS, B3H 1V7, Canada
| | - Lucy Ward
- Department of Medical Physics, Nova Scotia Health Authority, Queen Elizabeth II Health Sciences Centre, Halifax, NS, B3H 1V7, Canada
| | - Christopher G Thomas
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4J5, Canada.,Department of Medical Physics, Nova Scotia Health Authority, Queen Elizabeth II Health Sciences Centre, Halifax, NS, B3H 1V7, Canada.,Department of Radiation Oncology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.,Department of Radiology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
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Neph R, Ouyang C, Neylon J, Yang Y, Sheng K. Parallel beamlet dose calculation via beamlet contexts in a distributed multi-GPU framework. Med Phys 2019; 46:3719-3733. [PMID: 31183871 DOI: 10.1002/mp.13651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Dose calculation is one of the most computationally intensive, yet essential tasks in the treatment planning process. With the recent interest in automatic beam orientation and arc trajectory optimization techniques, there is a great need for more efficient model-based dose calculation algorithms that can accommodate hundreds to thousands of beam candidates at once. Foundational work has shown the translation of dose calculation algorithms to graphical processing units (GPUs), lending to remarkable gains in processing efficiency. But these methods provide parallelization of dose for only a single beamlet, serializing the calculation of multiple beamlets and under-utilizing the potential of modern GPUs. In this paper, the authors propose a framework enabling parallel computation of many beamlet doses using a novel beamlet context transformation and further embed this approach in a scalable network of multi-GPU computational nodes. METHODS The proposed context-based transformation separates beamlet-local density and TERMA into distinct beamlet contexts that independently provide sufficient data for beamlet dose calculation. Beamlet contexts are arranged in a composite context array with dosimetric isolation, and the context array is subjected to a GPU collapsed-cone convolution superposition procedure, producing the set of beamlet-specific dose distributions in a single pass. Dose from each context is converted to a sparse representation for efficient storage and retrieval during treatment plan optimization. The context radius is a new parameter permitting flexibility between the speed and fidelity of the dose calculation process. A distributed manager-worker architecture is constructed around the context-based GPU dose calculation approach supporting an arbitrary number of worker nodes and resident GPUs. Phantom experiments were executed to verify the accuracy of the context-based approach compared to Monte Carlo and a reference CPU-CCCS implementation for single beamlets and broad beams composed by addition of beamlets. Dose for representative 4π beam sets was calculated in lung and prostate cases to compare its efficiency with that of an existing beamlet-sequential GPU-CCCS implementation. Code profiling was also performed to evaluate the scalability of the framework across many networked GPUs. RESULTS The dosimetric accuracy of the context-based method displays <1.35% and 2.35% average error from the existing serialized CPU-CCCS algorithm and Monte Carlo simulation for beamlet-specific PDDs in water and slab phantoms, respectively. The context-based method demonstrates substantial speedup of up to two orders of magnitude over the beamlet-sequential GPU-CCCS method in the tested configurations. The context-based framework demonstrates near linear scaling in the number of distributed compute nodes and GPUs employed, indicating that it is flexible enough to meet the performance requirements of most users by simply increasing the hardware utilization. CONCLUSIONS The context-based approach demonstrates a new expectation of performance for beamlet-based dose calculation methods. This approach has been successful in accelerating the dose calculation process for very large-scale treatment planning problems - such as automatic 4π IMRT beam orientation and VMAT arc trajectory selection, with hundreds of thousands of beamlets - in clinically feasible timeframes. The flexibility of this framework makes it as a strong candidate for use in a variety of other very large-scale treatment planning tasks and clinical workflows.
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Affiliation(s)
- Ryan Neph
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Cheng Ouyang
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - John Neylon
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Youming Yang
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
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Smyth G, Evans PM, Bamber JC, Bedford JL. Recent developments in non-coplanar radiotherapy. Br J Radiol 2019; 92:20180908. [PMID: 30694086 PMCID: PMC6580906 DOI: 10.1259/bjr.20180908] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 11/05/2022] Open
Abstract
This paper gives an overview of recent developments in non-coplanar intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Modern linear accelerators are capable of automating motion around multiple axes, allowing efficient delivery of highly non-coplanar radiotherapy techniques. Novel techniques developed for C-arm and non-standard linac geometries, methods of optimization, and clinical applications are reviewed. The additional degrees of freedom are shown to increase the therapeutic ratio, either through dose escalation to the target or dose reduction to functionally important organs at risk, by multiple research groups. Although significant work is still needed to translate these new non-coplanar radiotherapy techniques into the clinic, clinical implementation should be prioritized. Recent developments in non-coplanar radiotherapy demonstrate that it continues to have a place in modern cancer treatment.
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Affiliation(s)
- Gregory Smyth
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | | | - Jeffrey C Bamber
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - James L Bedford
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
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Smyth G, Evans PM, Bamber JC, Mandeville HC, Rollo Moore A, Welsh LC, Saran FH, Bedford JL. Dosimetric accuracy of dynamic couch rotation during volumetric modulated arc therapy (DCR-VMAT) for primary brain tumours. Phys Med Biol 2019; 64:08NT01. [PMID: 30808011 PMCID: PMC6877349 DOI: 10.1088/1361-6560/ab0a8e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Radiotherapy treatment plans using dynamic couch rotation during volumetric modulated arc therapy (DCR-VMAT) reduce the dose to organs at risk (OARs) compared to coplanar VMAT, while maintaining the dose to the planning target volume (PTV). This paper seeks to validate this finding with measurements. DCR-VMAT treatment plans were produced for five patients with primary brain tumours and delivered using a commercial linear accelerator (linac). Dosimetric accuracy was assessed using point dose and radiochromic film measurements. Linac-recorded mechanical errors were assessed by extracting deviations from log files for multi-leaf collimator (MLC), couch, and gantry positions every 20 ms. Dose distributions, reconstructed from every fifth log file sample, were calculated and used to determine deviations from the treatment plans. Median (range) treatment delivery times were 125 s (123-133 s) for DCR-VMAT, compared to 78 s (64-130 s) for coplanar VMAT. Absolute point doses were 0.8% (0.6%-1.7%) higher than prediction. For coronal and sagittal films, respectively, 99.2% (96.7%-100%) and 98.1% (92.9%-99.0%) of pixels above a 20% low dose threshold reported gamma <1 for 3% and 3 mm criteria. Log file analysis showed similar gantry rotation root-mean-square error (RMSE) for VMAT and DCR-VMAT. Couch rotation RMSE for DCR-VMAT was 0.091° (0.086-0.102°). For delivered dose reconstructions, 100% of pixels above a 5% low dose threshold reported gamma <1 for 2% and 2 mm criteria in all cases. DCR-VMAT, for the primary brain tumour cases studied, can be delivered accurately using a commercial linac.
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Affiliation(s)
- Gregory Smyth
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom. Author to whom any correspondence should be addressed
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