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Bertholet J, Mackeprang PH, Loebner HA, Mueller S, Guyer G, Frei D, Volken W, Elicin O, Aebersold DM, Fix MK, Manser P. Comparison of Dynamic Trajectory Radiotherapy and Volumetric Modulated Arc Therapy for Loco-Regionally Advanced Oropharyngeal Cancer. Int J Radiat Oncol Biol Phys 2023; 117:e644. [PMID: 37785917 DOI: 10.1016/j.ijrobp.2023.06.2057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Dynamic trajectory radiotherapy (DTRT) extends volumetric modulated arc therapy (VMAT) with dynamic table and collimator rotation. We investigate the potential benefit of DTRT over VMAT with respect to organ-at-risk (OAR) sparing for patients with loco-regionally advanced oropharyngeal cancer (OPC). MATERIALS/METHODS We created DTRT and VMAT plans for 46 cases with prescribed doses of 50-70 Gy (2 Gy fractions, sequential boost) using 6 MV flattened beam on c-arm Linacs. For DTRT: case-specific collision avoidance maps were created and gantry-table paths were determined based on contoured structures to minimize fractional target/OAR overlap in beam's eye view. Gantry-collimator paths minimized field width in the leaf-travel direction. DTRT paths were imported in a research version of a commercial treatment planning system for intensity modulation optimization using the same optimizer and dose calculation algorithms as for VMAT. Plans at each dose level were normalized with 100% of the prescribed dose to 95% of the planning target volume (PTV). PTV coverage and OAR sparing for DTRT and VMAT were compared using Wilcoxon matched-pair signed rank test (5% significance level). The correlation between the fractional OAR/PTV50Gy volume overlap and difference in OAR Dmean between the two techniques was evaluated using Spearman's correlation coefficient. RESULTS Plans at each dose level were all acceptable and had D0.03cc<110% prescription dose (difference between DTRT and VMAT were not statistically significant). In the combined plans, PTV50Gy D95% and D98% and PTV70Gy D95% were significantly higher with DTRT compared to VMAT. Differences in PTV66Gy coverage and PTV70Gy D5% were not statistically significant. Mean Dmean to the contralateral (CL) parotid gland was 13.99 / 15.28 Gy for DTRT / VMAT respectively, it was 25.75 / 28.05 Gy for the CL submandibular gland, 44.88 / 45.82 Gy for the pharynx and 30.90 / 33.93 Gy for the oral cavity (all with p<.001). Mean Dmean to the ipsilateral (IL) parotid gland was 29.00 / 29.28 Gy for DTRT / VMAT respectively (p = .77) and 57.71 / 57.91 Gy for the IL submandibular gland (p = .99). Significantly higher doses were observed with DTRT than with VMAT for the optical and auditory OARs and for the brain, but well below the clinical goals. The difference in Dmean (VMAT-DTRT) was negatively correlated to the fractional OAR/PTV50Gy overlap for the CL parotid and submandibular gland and the IL submandibular gland (r = -0.55 to -0.51, p<.001) but not for IL parotid gland (r = -0.17, p = .26), oral cavity (r = -0.13, p = .41) or pharynx (r = -011, p = .47). CONCLUSION For at least the same target coverage, DTRT statistically significantly improves sparing for OARs related to salivary and swallowing functions compared to state-of-the-art VMAT. The advantage of DTRT decreases with increasing fractional OAR/PTV50Gy volume overlap for some salivary glands but not for pharynx or oral cavity. DTRT is promising to reduce treatment-related toxicity for patients with OPC.
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Affiliation(s)
- J Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - P H Mackeprang
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - H A Loebner
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - S Mueller
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - G Guyer
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - O Elicin
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D M Aebersold
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Fix MK, Frei D, Mueller S, Guyer G, Loebner HA, Volken W, Manser P. Auto-commissioning of a Monte Carlo electron beam model with application to photon MLC shaped electron fields. Phys Med Biol 2023; 68. [PMID: 36716491 DOI: 10.1088/1361-6560/acb755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/30/2023] [Indexed: 02/01/2023]
Abstract
Objective.Presently electron beam treatments are delivered using dedicated applicators. An alternative is the usage of the already installed photon multileaf collimator (pMLC) enabling efficient electron treatments. Currently, the commissioning of beam models is a manual and time-consuming process. In this work an auto-commissioning procedure for the Monte Carlo (MC) beam model part representing the beam above the pMLC is developed for TrueBeam systems with electron energies from 6 to 22 MeV.Approach.The analytical part of the electron beam model includes a main source representing the primary beam and a jaw source representing the head scatter contribution each consisting of an electron and a photon component, while MC radiation transport is performed for the pMLC. The auto-commissioning of this analytical part relies on information pre-determined from MC simulations, in-air dose profiles and absolute dose measurements in water for different field sizes and source to surface distances (SSDs). For validation calculated and measured dose distributions in water were compared for different field sizes, SSDs and beam energies for eight TrueBeam systems. Furthermore, a sternum case in an anthropomorphic phantom was considered and calculated and measured dose distributions were compared at different SSDs.Main results.Instead of the manual commissioning taking up to several days of calculation time and several hours of user time, the auto-commissioning is carried out in a few minutes. Measured and calculated dose distributions agree generally within 3% of maximum dose or 2 mm. The gamma passing rates for the sternum case ranged from 96% to 99% (3% (global)/2 mm criteria, 10% threshold).Significance.The auto-commissioning procedure was successfully implemented and applied to eight TrueBeam systems. The newly developed user-friendly auto-commissioning procedure allows an efficient commissioning of an MC electron beam model and eases the usage of advanced electron radiotherapy utilizing the pMLC for beam shaping.
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Affiliation(s)
- M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - S Mueller
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - G Guyer
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - H A Loebner
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Mueller S, Guyer G, Volken W, Frei D, Torelli N, Aebersold DM, Manser P, Fix MK. Efficiency enhancements of a Monte Carlo beamlet based treatment planning process: implementation and parameter study. Phys Med Biol 2023; 68. [PMID: 36655485 DOI: 10.1088/1361-6560/acb480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/18/2023] [Indexed: 01/20/2023]
Abstract
Objective.The computational effort to perform beamlet calculation, plan optimization and final dose calculation of a treatment planning process (TPP) generating intensity modulated treatment plans is enormous, especially if Monte Carlo (MC) simulations are used for dose calculation. The goal of this work is to improve the computational efficiency of a fully MC based TPP for static and dynamic photon, electron and mixed photon-electron treatment techniques by implementing multiple methods and studying the influence of their parameters.Approach.A framework is implemented calculating MC beamlets efficiently in parallel on each available CPU core. The user can specify the desired statistical uncertainty of the beamlets, a fractional sparse dose threshold to save beamlets in a sparse format and minimal distances to the PTV surface from which 2 × 2 × 2 = 8 (medium) or even 4 × 4 × 4 = 64 (large) voxels are merged. The compromise between final plan quality and computational efficiency of beamlet calculation and optimization is studied for several parameter values to find a reasonable trade-off. For this purpose, four clinical and one academic case are considered with different treatment techniques.Main results.Setting the statistical uncertainty to 5% (photon beamlets) and 15% (electron beamlets), the fractional sparse dose threshold relative to the maximal beamlet dose to 0.1% and minimal distances for medium and large voxels to the PTV to 1 cm and 2 cm, respectively, does not lead to substantial degradation in final plan quality compared to using 2.5% (photon beamlets) and 5% (electron beamlets) statistical uncertainty and no sparse format nor voxel merging. Only OAR sparing is slightly degraded. Furthermore, computation times are reduced by about 58% (photon beamlets), 88% (electron beamlets) and 96% (optimization).Significance.Several methods are implemented improving computational efficiency of beamlet calculation and plan optimization of a fully MC based TPP without substantial degradation in final plan quality.
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Affiliation(s)
- S Mueller
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - G Guyer
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - N Torelli
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - D M Aebersold
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
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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] [What about the content of this article? (0)] [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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Loebner HA, Volken W, Mueller S, Bertholet J, Mackeprang PH, Guyer G, Aebersold DM, Stampanoni M, Manser P, Fix MK. Development of a Monte Carlo based robustness calculation and evaluation tool. Med Phys 2022; 49:4780-4793. [PMID: 35451087 PMCID: PMC9545707 DOI: 10.1002/mp.15683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/01/2022] [Accepted: 04/03/2022] [Indexed: 11/09/2022] Open
Abstract
Background Evaluating plan robustness is a key step in radiotherapy. Purpose To develop a flexible Monte Carlo (MC)‐based robustness calculation and evaluation tool to assess and quantify dosimetric robustness of intensity‐modulated radiotherapy (IMRT) treatment plans by exploring the impact of systematic and random uncertainties resulting from patient setup, patient anatomy changes, and mechanical limitations of machine components. Methods The robustness tool consists of two parts: the first part includes automated MC dose calculation of multiple user‐defined uncertainty scenarios to populate a robustness space. An uncertainty scenario is defined by a certain combination of uncertainties in patient setup, rigid intrafraction motion and in mechanical steering of the following machine components: angles of gantry, collimator, table‐yaw, table‐pitch, table‐roll, translational positions of jaws, multileaf‐collimator (MLC) banks, and single MLC leaves. The Swiss Monte Carlo Plan (SMCP) is integrated in this tool to serve as the backbone for the MC dose calculations incorporating the uncertainties. The calculated dose distributions serve as input for the second part of the tool, handling the quantitative evaluation of the dosimetric impact of the uncertainties. A graphical user interface (GUI) is developed to simultaneously evaluate the uncertainty scenarios according to user‐specified conditions based on dose‐volume histogram (DVH) parameters, fast and exact gamma analysis, and dose differences. Additionally, a robustness index (RI) is introduced with the aim to simultaneously evaluate and condense dosimetric robustness against multiple uncertainties into one number. The RI is defined as the ratio of scenarios passing the conditions on the dose distributions. Weighting of the scenarios in the robustness space is possible to consider their likelihood of occurrence. The robustness tool is applied on IMRT, a volumetric modulated arc therapy (VMAT), a dynamic trajectory radiotherapy (DTRT), and a dynamic mixed beam radiotherapy (DYMBER) plan for a brain case to evaluate the robustness to uncertainties of gantry‐, table‐, collimator angle, MLC, and intrafraction motion. Additionally, the robustness of the IMRT, VMAT, and DTRT plan against patient setup uncertainties are compared. The robustness tool is validated by Delta4 measurements for scenarios including all uncertainty types available. Results The robustness tool performs simultaneous calculation of uncertainty scenarios, and the GUI enables their fast evaluation. For all evaluated plans and uncertainties, the planning target volume (PTV) margin prevented major clinical target volume (CTV) coverage deterioration (maximum observed standard deviation of D98%CTV was 1.3 Gy). OARs close to the PTV experienced larger dosimetric deviations (maximum observed standard deviation of D2%chiasma was 14.5 Gy). Robustness comparison by RI evaluation against patient setup uncertainties revealed better dosimetric robustness of the VMAT and DTRT plans as compared to the IMRT plan. Delta4 validation measurements agreed with calculations by >96% gamma‐passing rate (3% global/2 mm). Conclusions The robustness tool was successfully implemented. Calculation and evaluation of uncertainty scenarios with the robustness tool were demonstrated on a brain case. Effects of patient and machine‐specific uncertainties and the combination thereof on the dose distribution are evaluated in a user‐friendly GUI to quantitatively assess and compare treatment plans and their robustness.
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Affiliation(s)
- H A Loebner
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - S Mueller
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - J Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - P-H Mackeprang
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - G Guyer
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D M Aebersold
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - Mfm Stampanoni
- Institute for Biomedical Engineering, ETH Zürich and PSI, Villigen, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Mueller S, Guyer G, Risse T, Tessarini S, Aebersold DM, Stampanoni MFM, Fix MK, Manser P. A hybrid column generation and simulated annealing algorithm for direct aperture optimization. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac58db] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 02/25/2022] [Indexed: 11/11/2022]
Abstract
Abstract
The purpose of this work was to develop a hybrid column generation (CG) and simulated annealing (SA) algorithm for direct aperture optimization (H-DAO) and to show its effectiveness in generating high quality treatment plans for intensity modulated radiation therapy (IMRT) and mixed photon-electron beam radiotherapy (MBRT). The H-DAO overcomes limitations of the CG-DAO with two features improving aperture selection (branch-feature) and enabling aperture shape changes during optimization (SA-feature). The H-DAO algorithm iteratively adds apertures to the plan. At each iteration, a branch is created for each field provided. First, each branch determines the most promising aperture of its assigned field and adds it to a copy of the current apertures. Afterwards, the apertures of each branch undergo an MU-weight optimization followed by an SA-based simultaneous shape and MU-weight optimization and a second MU-weight optimization. The next H-DAO iteration continues the branch with the lowest objective function value. IMRT and MBRT treatment plans for an academic, a brain and a head and neck case generated using the CG-DAO and H-DAO were compared. For every investigated case and both IMRT and MBRT, the H-DAO leads to a faster convergence of the objective function value with number of apertures compared to the CG-DAO. In particular, the H-DAO needs about half the apertures to reach the same objective function value as the CG-DAO. The average aperture areas are 27% smaller for H-DAO than for CG-DAO leading to a slightly larger discrepancy between optimized and final dose. However, a dosimetric benefit remains. The H-DAO was successfully developed and applied to IMRT and MBRT. The faster convergence with number of apertures of the H-DAO compared to the CG-DAO allows to select a better compromise between plan quality and number of apertures.
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Bertholet J, Mackeprang P, Mueller S, Volken W, Frei D, Elicin O, Aebersold D, Fix M, Manser P. PH-0377 Organ-at-risk sparing in head and neck radiotherapy with dynamic trajectory radiotherapy. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07308-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kueng R, Mueller S, Loebner HA, Frei D, Volken W, Aebersold DM, Stampanoni MFM, Fix MK, Manser P. TriB-RT: Simultaneous optimization of photon, electron and proton beams. Phys Med Biol 2021; 66:045006. [PMID: 32413883 DOI: 10.1088/1361-6560/ab936f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop a novel treatment planning process (TPP) with simultaneous optimization of modulated photon, electron and proton beams for improved treatment plan quality in radiotherapy. METHODS A framework for fluence map optimization of Monte Carlo (MC) calculated beamlet dose distributions is developed to generate treatment plans consisting of photon, electron and spot scanning proton fields. Initially, in-house intensity modulated proton therapy (IMPT) plans are compared to proton plans created by a commercial treatment planning system (TPS). A triple beam radiotherapy (TriB-RT) plan is generated for an exemplary academic case and the dose contributions of the three particle types are investigated. To investigate the dosimetric potential, a TriB-RT plan is compared to an in-house IMPT plan for two clinically motivated cases. Benefits of TriB-RT for a fixed proton beam line with a single proton field are investigated. RESULTS In-house optimized IMPT are of at least equal or better quality than TPS-generated proton plans, and MC-based optimization shows dosimetric advantages for inhomogeneous situations. Concerning TriB-RT, for the academic case, the resulting plan shows substantial contribution of all particle types. For the clinically motivated case, improved sparing of organs at risk close to the target volume is achieved compared to IMPT (e.g. myelon and brainstem [Formula: see text] -37%) at cost of an increased low dose bath (healthy tissue V 10% +22%). In the scenario of a fixed proton beam line, TriB-RT plans are able to compensate the loss in degrees of freedom to substantially improve plan quality compared to a single field proton plan. CONCLUSION A novel TPP which simultaneously optimizes photon, electron and proton beams was successfully developed. TriB-RT shows the potential for improved treatment plan quality and is especially promising for cost-effective single-room proton solutions with a fixed beamline in combination with a conventional linac delivering photon and electron fields.
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Affiliation(s)
- R Kueng
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Kiss M, Zhang H, Fix M, Manser P, Xing L. Z-Super Resolution CT-Image Generation With A Deep 3D Fully Convolutional Neural Network. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fix M, Mueller S, Frei D, Volken W, Terribilini D, Frauchiger D, Joosten A, Henzen A, Herrmann E, Aebersold D, Manser P. PD-0304: Treatment plan comparisons between dynamic trajectory radiotherapy and HyperArc. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00328-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fix M, Mueller S, Volken W, Terribilini D, Frei D, Elicin O, Aebersold D, Manser P. Dosimetric Comparison of Dynamic Trajectory Radiotherapy, HyperArc and VMAT Treatment Plans. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Manser P, Mueller S, Guyer G, Koechli C, Volken W, Bertholet J, Aebersold D, Fix M. Advanced Dynamic Trajectory Radiotherapy Using Table Translations and Rotations. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schmidhalter D, Henzen D, Herrmann E, Volken W, Mackeprang P, Ermis E, Hemmatazad H, Honegger J, Haas B, Fix M, Manser P. PO-1501: Frameless workflow for radiosurgery of arteriovenous malformations - A new software prototype. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01519-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kueng R, Guyer G, Volken W, Frei D, Stabel F, Stampanoni MFM, Manser P, Fix MK. Development of an extended Macro Monte Carlo method for efficient and accurate dose calculation in magnetic fields. Med Phys 2020; 47:6519-6530. [PMID: 33075168 DOI: 10.1002/mp.14542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 11/06/2022] Open
Abstract
MOTIVATION Progress in the field of magnetic resonance (MR)-guided radiotherapy has triggered the need for fast and accurate dose calculation in presence of magnetic fields. The aim of this work is to satisfy this need by extending the macro Monte Carlo (MMC) method to enable dose calculation for photon, electron, and proton beams in a magnetic field. METHODS The MMC method is based on the transport of particles in macroscopic steps through an absorber by sampling the relevant physical quantities from a precalculated database containing probability distribution functions. To enable MMC particle transport in a magnetic field, a transformation accounting for the Lorentz force is applied for each macro step by rotating the sampled position and direction around the magnetic field vector. The transformed position and direction distributions on local geometries are validated against full MC for electron and proton pencil beams. To enable photon dose calculation, an in-house MC algorithm is used for photon transport and interaction. Emerging secondary charged particles are passed to MMC for transport and energy deposition. The extended MMC dose calculation accuracy and efficiency is assessed by comparison with EGSnrc (photon and electron beams) and Geant4 (proton beam) calculated dose distributions of different energies and homogeneous magnetic fields for broad beams impinging on water phantoms with bone and lung inhomogeneities. RESULTS The geometric transformation on the local geometries is able to reproduce the results of full MC for all investigated settings (difference in mean value and standard deviation <1%). Macro Monte Carlo calculated dose distributions in a homogeneous magnetic field are in agreement with EGSnrc and Geant4, respectively, with gamma passing rates >99.6% (global 2%, 2 mm and 10% threshold criteria) for all situations. MMC achieves a substantial efficiency gain of up to a factor of 21 (photon beam), 66 (electron beam), and 356 (proton beam) compared to EGSnrc or Geant4. CONCLUSION Efficient and accurate dose calculation in magnetic fields was successfully enabled by utilizing the developed extended MMC transport method for photon, electron, and proton beams.
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Affiliation(s)
- R Kueng
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - G Guyer
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - F Stabel
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - M F M Stampanoni
- Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Kueng R, Oborn B, Roberts N, Causer T, Stampanoni M, Manser P, Keall P, Fix M. Towards MR-guided electron therapy: Measurement and simulation of clinical electron beams in magnetic fields. Phys Med 2020; 78:83-92. [DOI: 10.1016/j.ejmp.2020.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/17/2020] [Accepted: 09/01/2020] [Indexed: 10/23/2022] Open
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Mackeprang PH, Vuong D, Volken W, Henzen D, Schmidhalter D, Malthaner M, Mueller S, Frei D, Kilby W, Aebersold DM, Fix MK, Manser P. Benchmarking Monte-Carlo dose calculation for MLC CyberKnife treatments. Radiat Oncol 2019; 14:172. [PMID: 31533746 PMCID: PMC6751815 DOI: 10.1186/s13014-019-1370-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/27/2019] [Indexed: 11/28/2022] Open
Abstract
Background Vendor-independent Monte Carlo (MC) dose calculation (IDC) for patient-specific quality assurance of multi-leaf collimator (MLC) based CyberKnife treatments is used to benchmark and validate the commercial MC dose calculation engine for MLC based treatments built into the CyberKnife treatment planning system (Precision MC). Methods The benchmark included dose profiles in water in 15 mm depth and depth dose curves of rectangular MLC shaped fields ranging from 7.6 mm × 7.7 mm to 115.0 mm × 100.1 mm, which were compared between IDC, Precision MC and measurements in terms of dose difference and distance to agreement. Dose distributions of three phantom cases and seven clinical lung cases were calculated using both IDC and Precision MC. The lung PTVs ranged from 14 cm3 to 93 cm3. Quantitative comparison of these dose distributions was performed using dose-volume parameters and 3D gamma analysis with 2% global dose difference and 1 mm distance criteria and a global 10% dose threshold. Time to calculate dose distributions was recorded and efficiency was assessed. Results Absolute dose profiles in 15 mm depth in water showed agreement between Precision MC and IDC within 3.1% or 1 mm. Depth dose curves agreed within 2.3% / 1 mm. For the phantom and clinical lung cases, mean PTV doses differed from − 1.0 to + 2.3% between IDC and Precision MC and gamma passing rates were > =98.1% for all multiple beam treatment plans. For the lung cases, lung V20 agreed within ±1.5%. Calculation times ranged from 2.2 min (for 39 cm3 PTV at 1.0 × 1.0 × 2.5 mm3 native CT resolution) to 8.1 min (93 cm3 at 1.1 × 1.1 × 1.0 mm3), at 2% uncertainty for Precision MC for the 7 examined lung cases and 4–6 h for IDC, which, however, is not optimized for efficiency but used as a gold standard for accuracy. Conclusions Both accuracy and efficiency of Precision MC in the context of MLC based planning for the CyberKnife M6 system were benchmarked against MC based IDC framework. Precision MC is used in clinical practice at our institute.
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Affiliation(s)
- P-H Mackeprang
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland.
| | - D Vuong
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D Henzen
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D Schmidhalter
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - M Malthaner
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - S Mueller
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - W Kilby
- Accuray Incorporated, Sunnyvale, CA, USA
| | - D M Aebersold
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Herrmann E, Ermiş E, Meier R, Blatti-Moreno M, Knecht U, Aebersold D, Manser P, Mauricio R. Fully Automated Segmentation of the Brain Resection Cavity for Radiation Target Volume Definition in Glioblastoma Patients. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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18
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Volken W, Zulliger MA, Koller B, Manser P, Fix MK. Investigation on the resolution of a micro cone beam CT scanner scintillating detector using Monte Carlo methods. Phys Med 2018; 53:17-24. [PMID: 30241750 DOI: 10.1016/j.ejmp.2018.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/13/2018] [Accepted: 08/05/2018] [Indexed: 11/19/2022] Open
Abstract
The impact of several physical quantities on the spatial resolution of an X-ray scintillating pixel detector for a micro cone beam CT (µCBCT) is investigated and discussed. The XtremeCT from SCANCO Medical AG was simulated using the EGSnrc/EGS++ Monte Carlo (MC) framework and extensively benchmarked in a previous work. The resolution of the detector was determined by simulating a titanium knife-edge to obtain the edge spread function (ESF) and the modulation transfer function (MTF). Propagation of the scintillation light through the scintillator and its coupling into the fiber optics system was taken into account. The contribution of particles scattered in the main scanner components to the detector signal is very low and does not affect the spatial resolution of the detector. The resolution obtained from the energy deposition in the scintillator without any blurring due to the propagation of the scintillation light into the fiber optics array was 31 µm. By assuming isotropic light propagation in the scintillator, the resolution degraded to 360 µm. A simple light propagation model taking into account the impact of the scintillator's columnar microstructures was developed and compared with the MANTIS Monte Carlo simulation package. By reducing the width of the model's light propagation kernel by a factor of 2 compared to the isotropic case, the detector resolution can be improved to 83 µm, which corresponds well to the measured resolution of 86 µm. The resolution of the detector is limited mainly by the propagation of the scintillation light through the scintillator layer. It offers the greatest potential to improve the resolution of the µCBCT imaging system.
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Affiliation(s)
- W Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | | | - B Koller
- SCANCO Medical AG, Brüttisellen, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland.
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Herrmann E, Ermis E, Jungo A, Blatti-Moreno M, Knecht U, Aebersold DM, Manser P, Reyes M. P01.088 Brain resection cavity delineation for radiation target volume definition in glioblastoma patients using deep learning. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy139.130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- E Herrmann
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerl
| | - E Ermis
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerl
| | - A Jungo
- Institute for Surgical Technology and Biomechanics, Bern, Switzerl
| | - M Blatti-Moreno
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerl
| | - U Knecht
- Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital, Bern, Switzerl
| | - D M Aebersold
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerl
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - M Reyes
- Institute for Surgical Technology and Biomechanics, Bern, Switzerl
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Herrmann E, Terribilini D, Manser P, Fix MK, Toporek G, Candinas D, Weber S, Aebersold DM, Loessl K. Accuracy assessment of a potential clinical use of navigation-guided intra-operative liver metastasis brachytherapy-a planning study. Strahlenther Onkol 2018; 194:1030-1038. [PMID: 30022277 PMCID: PMC6208950 DOI: 10.1007/s00066-018-1334-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 06/28/2018] [Indexed: 11/29/2022]
Abstract
For patients with inoperable liver metastases, intra-operative liver high dose-rate brachytherapy (HDR-BT) is a promising technology enabling delivery of a high radiation dose to the tumor, while sparing healthy tissue. Liver brachytherapy has been described in the literature as safe and effective for the treatment of primary or secondary hepatic malignancies. It is preferred over other ablative techniques for lesions that are either larger than 4 cm or located in close proximity to large vessels or the common bile duct. In contrast to external beam radiation techniques, organ movements do not affect the size of the irradiated volume in intra-operative HDR-BT and new technical solutions exist to support image guidance for intra-operative HDR-BT. We have retrospectively analyzed anonymized CT datasets of 5 patients who underwent open liver surgery (resection and/or ablation) in order to test whether the accuracy of a new image-guidance method specifically adapted for intra-operative HDR-BT is high enough to use it in similar situations and whether patients could potentially benefit from navigation-guided intra-operative needle placement for liver HDR-BT.
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Affiliation(s)
- E Herrmann
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Freiburgstr., 3010, Bern, Switzerland.
| | - D Terribilini
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - G Toporek
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - D Candinas
- Department of Visceral Surgery and Medicine, Inselspital, Berne University Hospital, University of Berne, Bern, Switzerland
| | - S Weber
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - D M Aebersold
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Freiburgstr., 3010, Bern, Switzerland
| | - K Loessl
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Freiburgstr., 3010, Bern, Switzerland
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Mueller S, Manser P, Volken W, Frei D, Kueng R, Herrmann E, Elicin O, Aebersold DM, Stampanoni MFM, Fix MK. Part 2: Dynamic mixed beam radiotherapy (DYMBER): Photon dynamic trajectories combined with modulated electron beams. Med Phys 2018; 45:4213-4226. [PMID: 29992574 DOI: 10.1002/mp.13085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to develop a treatment technique for dynamic mixed beam radiotherapy (DYMBER) utilizing increased degrees of freedom (DoF) of a conventional treatment unit including different particle types (photons and electrons), intensity and energy modulation and dynamic gantry, table, and collimator rotations. METHODS A treatment planning process has been developed to create DYMBER plans combining photon dynamic trajectories (DTs) and step and shoot electron apertures collimated with the photon multileaf collimator (pMLC). A gantry-table path is determined for the photon DTs with minimized overlap of the organs at risk (OARs) with the target. In addition, an associated dynamic collimator rotation is established with minimized area between the pMLC leaves and the target contour. pMLC sequences of photon DTs and electron pMLC apertures are then simultaneously optimized using direct aperture optimization (DAO). Subsequently, the final dose distribution of the electron pMLC apertures is calculated using the Swiss Monte Carlo Plan (SMCP). The pMLC sequences of the photon DTs are then re-optimized with a finer control point resolution and with the final electron dose distribution taken into account. Afterwards, the final photon dose distribution is calculated also using the SMCP and summed together with the one of the electrons. This process is applied for a brain and two head and neck cases. The resulting DYMBER dose distributions are compared to those of dynamic trajectory radiotherapy (DTRT) plans consisting only of photon DTs and clinically applied VMAT plans. Furthermore, the deliverability of the DYMBER plans is verified in terms of dosimetric accuracy, delivery time and collision avoidance. For this purpose, The DYMBER plans are delivered to Gafchromic EBT3 films placed in an anthropomorphic head phantom on a Varian TrueBeam linear accelerator. RESULTS For each case, the dose homogeneity in the target is similar or better for DYMBER compared to DTRT and VMAT. Averaged over all three cases, the mean dose to the parallel OARs is 16% and 28% lower, D2% to the serial OARs is 17% and 37% lower and V10% to normal tissue is 12% and 4% lower for the DYMBER plans compared to the DTRT and VMAT plans, respectively. The DYMBER plans are delivered without collision and with a 4-5 min longer delivery time than the VMAT plans. The absolute dose measurements are compared to calculation by gamma analysis using 2% (global)/2 mm criteria with passing rates of at least 99%. CONCLUSIONS A treatment technique for DYMBER has been successfully developed and verified for its deliverability. The dosimetric superiority of DYMBER over DTRT and VMAT indicates utilizing increased DoF to be the key to improve brain and head and neck radiation treatments in future.
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Affiliation(s)
- S Mueller
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - P Manser
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - W Volken
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - D Frei
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - R Kueng
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - E Herrmann
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - O Elicin
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - D M Aebersold
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
| | - M F M Stampanoni
- Institute for Biomedical Engineering, ETH Zürich and PSI, CH-5232, Villigen, Switzerland
| | - M K Fix
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland
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Joosten A, Müller S, Henzen D, Volken W, Frei D, Aebersold DM, Manser P, Fix MK. A dosimetric evaluation of different levels of energy and intensity modulation for inversely planned multi-field MERT. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aabe40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mackeprang P, Vuong D, Volken W, Henzen D, Schmidhalter D, Malthaner M, Mueller S, Frei D, Aebersold D, Fix M, Manser P. EP-1842: Benchmarking of Monte Carlo dose calculation for MLC based CyberKnife Radiotherapy. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32151-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mueller S, Risse T, Fix M, Tessarini S, Mueller F, Zaugg K, Stampanoni M, Manser P. EP-1930: Mixed beam radiotherapy for sternum and lung treatments. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32239-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mueller S, Manser P, Volken W, Frei D, Aebersold D, Stampanoni M, Fix M. EP-1931: Suitability of dynamic trajectory mixed beam radiotherapy for head and neck and brain treatments. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32240-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schmidhalter D, Henzen D, Malthaner M, Herrmann E, Angelmann S, Hemmatazad H, Stieb S, Fix M, Manser P. EP-2185: Evaluation of the CK-11 version for the Cyberknife M6. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32494-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Mueller S, Fix MK, Henzen D, Frei D, Frauchiger D, Loessl K, Stampanoni MFM, Manser P. Electron beam collimation with a photon MLC for standard electron treatments. ACTA ACUST UNITED AC 2018; 63:025017. [DOI: 10.1088/1361-6560/aa9fb6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mackeprang PH, Vuong D, Volken W, Henzen D, Schmidhalter D, Malthaner M, Mueller S, Frei D, Stampanoni MFM, Dal Pra A, Aebersold DM, Fix MK, Manser P. Independent Monte-Carlo dose calculation for MLC based CyberKnife radiotherapy. ACTA ACUST UNITED AC 2017; 63:015015. [DOI: 10.1088/1361-6560/aa97f8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mueller S, Fix MK, Joosten A, Henzen D, Frei D, Volken W, Kueng R, Aebersold DM, Stampanoni MFM, Manser P. Simultaneous optimization of photons and electrons for mixed beam radiotherapy. ACTA ACUST UNITED AC 2017; 62:5840-5860. [DOI: 10.1088/1361-6560/aa70c5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Mackeprang P, Vuong D, Volken W, Henzen D, Schmidhalter D, Malthaner M, Mueller S, Frei D, Aebersold D, Fix M, Manser P. EP-1480: Patient-specific QA for CyberKnife MLC plans using Monte Carlo. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31915-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kueng R, Driscoll B, Manser P, Fix MK, Stampanoni M, Keller H. Quantification of local image noise variation in PET images for standardization of noise-dependent analysis metrics. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/3/2/025007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mueller S, Joosten A, Fix MK, Henzen D, Volken W, Frei D, Stampanoni MFM, Manser P. SU-F-T-89: Investigation of Simultaneous Optimization of Photon and Electron Apertures for Mixed Beam Radiotherapy Based On An Academic Case. Med Phys 2016. [DOI: 10.1118/1.4956225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Schmidhalter D, Henzen D, Malthaner M, Frauchiger D, Fix MK, Manser P. SU-F-T-586: Pre-Treatment QA of InCise2 MLC Plans On a Cyberknife-M6 Using the Delta4 System in SBRT. Med Phys 2016. [DOI: 10.1118/1.4956771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Henzen D, C Zanella C, Schmidhalter D, Volken W, Mackeprang PH, Malthaner M, K Fix M, Manser P. TH-AB-201-05: Determining the Direction Distribution of the Primary Radiation for a Cyberknife-M6. Med Phys 2016. [DOI: 10.1118/1.4958033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Mackeprang P, Volken W, Terribilini D, Frauchiger D, Klippel N, Zaugg K, Aebersold DM, Fix MK, Manser P. SU-F-T-412: Spatiotemporal Distribution of Dose Rates in VMAT Plans. Med Phys 2016. [DOI: 10.1118/1.4956597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Passarge M, Fix MK, Manser P, Stampanoni MFM, Siebers JV. MO-FG-202-07: Real-Time EPID-Based Detection Metric For VMAT Delivery Errors. Med Phys 2016. [DOI: 10.1118/1.4957310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kueng R, Manser P, Fix MK, Driscoll B, Stampanoni MFM, Keller H. SU-G-IeP4-13: PET Image Noise Variability and Its Consequences for Quantifying Tumor Hypoxia. Med Phys 2016. [DOI: 10.1118/1.4957108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Fix MK, Frei D, Volken W, Terribilini D, Aebersold DM, Manser P. TH-EF-BRB-02: Feasibility of Optimization for Dynamic Trajectory Radiotherapy. Med Phys 2016. [DOI: 10.1118/1.4958248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Mackeprang PH, Volken W, Terribilini D, Frauchiger D, Zaugg K, Aebersold DM, Fix MK, Manser P. Assessing dose rate distributions in VMAT plans. Phys Med Biol 2016; 61:3208-21. [PMID: 27025897 DOI: 10.1088/0031-9155/61/8/3208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Dose rate is an essential factor in radiobiology. As modern radiotherapy delivery techniques such as volumetric modulated arc therapy (VMAT) introduce dynamic modulation of the dose rate, it is important to assess the changes in dose rate. Both the rate of monitor units per minute (MU rate) and collimation are varied over the course of a fraction, leading to different dose rates in every voxel of the calculation volume at any point in time during dose delivery. Given the radiotherapy plan and machine specific limitations, a VMAT treatment plan can be split into arc sectors between Digital Imaging and Communications in Medicine control points (CPs) of constant and known MU rate. By calculating dose distributions in each of these arc sectors independently and multiplying them with the MU rate, the dose rate in every single voxel at every time point during the fraction can be calculated. Independently calculated and then summed dose distributions per arc sector were compared to the whole arc dose calculation for validation. Dose measurements and video analysis were performed to validate the calculated datasets. A clinical head and neck, cranial and liver case were analyzed using the tool developed. Measurement validation of synthetic test cases showed linac agreement to precalculated arc sector times within ±0.4 s and doses ±0.1 MU (one standard deviation). Two methods for the visualization of dose rate datasets were developed: the first method plots a two-dimensional (2D) histogram of the number of voxels receiving a given dose rate over the course of the arc treatment delivery. In similarity to treatment planning system display of dose, the second method displays the dose rate as color wash on top of the corresponding computed tomography image, allowing the user to scroll through the variation over time. Examining clinical cases showed dose rates spread over a continuous spectrum, with mean dose rates hardly exceeding 100 cGy min(-1) for conventional fractionation. A tool to analyze dose rate distributions in VMAT plans with sub-second accuracy was successfully developed and validated. Dose rates encountered in clinical VMAT test cases show a continuous spectrum with a mean less than or near 100 cGy min(-1) for conventional fractionation.
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Affiliation(s)
- P-H Mackeprang
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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Mackeprang P, Schmidhalter D, Henzen D, Malthaner M, Aebersold D, Manser P, Fix M. PO-0828: Dosimetric assessment of a second generation Multi-Leaf Collimator for robotic radiotherapy. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32078-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fix M, Frei D, Volken W, Terribilini D, Manser P. EP-1635: Volumetric modulated arc therapy optimization including dynamic collimator rotation. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32886-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Fix MK, Volken W, Frei D, Terribilini D, Aebersold DM, Manser P. TH-AB-BRB-05: Quantification and Visualization of Treatment Plan Robustness in Radiotherapy. Med Phys 2015. [DOI: 10.1118/1.4926136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Fix MK, Frei D, Volken W, Terribilini D, Manser P. SU-E-T-343: Dynamic Collimator Rotation for Volumetric Modulated Arc Therapy. Med Phys 2015. [DOI: 10.1118/1.4924704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Joosten A, Henzen D, Volken W, Frei D, Lössl K, Manser P, Fix M. EP-1459: Dosimetric evaluation of arc-based modulated electron radiation therapy. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)41451-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fix M, Volken W, Frei D, Terribilini D, Aebersold D, Manser P. PD-0527: Evaluation tool for plan robustness regarding patient setup using Monte Carlo methods. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40522-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Henzen D, Manser P, Frei D, Volken W, Neuenschwander H, Born EJ, Joosten A, Lössl K, Aebersold DM, Chatelain C, Stampanoni MFM, Fix MK. Beamlet based direct aperture optimization for MERT using a photon MLC. Med Phys 2014; 41:121711. [DOI: 10.1118/1.4901638] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Fix MK, Volken W, Frei D, Terribilini D, Dal Pra A, Schmuecking M, Manser P. SU-F-BRD-03: Determination of Plan Robustness for Systematic Setup Errors Using Trilinear Interpolation. Med Phys 2014. [DOI: 10.1118/1.4889057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Henzen D, Chatelain C, Manser P, Frei D, Volken W, Neuenschwander H, Joosten A, Loessl K, Aebersold DM, Fix MK. SU-E-T-148: Efficient Verification Method for Modulated Electron Radiotherapy Treatment Plans. Med Phys 2014. [DOI: 10.1118/1.4888478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Henzen D, Manser P, Frei D, Volken W, Neuenschwander H, Born EJ, Lössl K, Aebersold DM, Stampanoni MFM, Fix MK. Forward treatment planning for modulated electron radiotherapy (MERT) employing Monte Carlo methods. Med Phys 2014; 41:031712. [DOI: 10.1118/1.4866227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Fix M, Frauchiger D, Henrich L, Sassowsky M, Frei D, Terribilini D, Manser P. 71: Verification of dynamic trajectory radiotherapy based on Monte Carlo. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)34092-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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