scholarly journals An Integrated Framework Based on Full Monte Carlo Simulations for Double-Scattering Proton Therapy

2019 ◽  
Vol 6 (2) ◽  
pp. 31-41
Author(s):  
Jiankui Yuan ◽  
David Mansur ◽  
Min Yao ◽  
Tithi Biswas ◽  
Yiran Zheng ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Treatment Plan ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Double Scattering ◽  
Integrated Framework ◽  
End To End ◽  
Clinical Cases

ABSTRACT Purpose: We developed an integrated framework that employs a full Monte Carlo (MC) model for treatment-plan simulations of a passive double-scattering proton system. Materials and Methods: We have previously validated a virtual machine source model for full MC proton-dose calculations by comparing the percentage of depth-dose curves, spread-out Bragg peaks, and lateral profiles against measured commissioning data. This study further expanded our previous work by developing an integrate framework that facilitates its clinical use. Specifically, we have (1) constructed patient-specific applicator and compensator numerically from the plan data and incorporated them into the beamline, (2) created the patient anatomy from the computed tomography image and established the transformation between patient and machine coordinate systems, and (3) developed a graphical user interface to ease the whole process from importing the treatment plan in the Digital Imaging and Communications in Medicine format to parallelization of the MC calculations. End-to-end tests were performed to validate the functionality, and 3 clinical cases were used to demonstrate clinical utility of the framework. Results: The end-to-end tests demonstrated that the framework functioned correctly for all tested functionality. Comparisons between the treatment planning system calculations and MC results in 3 clinical cases revealed large dose difference up to 17%, especially in the beam penumbra and near the end of beam range. The discrepancy likely originates from a variety of sources, such as the dose algorithms, modeling of the beamline, and the dose metric. The agreement for other regions was acceptable. Conclusion: An integrated framework was developed for full MC simulations of double-scattering proton therapy. It can be a valuable tool for dose verification and plan evaluation.

scholarly journals Evaluation of Delta4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance

2020 ◽  
Vol 19 ◽  
pp. 153303382094581
Author(s):  
Du Tang ◽  
Zhen Yang ◽  
Xunzhang Dai ◽  
Ying Cao
Keyword(s):  
Quality Assurance ◽  
Treatment Planning ◽  
Treatment Plan ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Pencil Beam ◽  
Ion Chamber ◽  
Passing Rate ◽  
Gamma Passing Rate

Purpose: To evaluate the performance of Delta4DVH Anatomy in patient-specific intensity-modulated radiotherapy quality assurance. Materials and Methods: Dose comparisons were performed between Anatomy doses calculated with treatment plan dose measured modification and pencil beam algorithms, treatment planning system doses, film doses, and ion chamber measured doses in homogeneous and inhomogeneous geometries. The sensitivity of Anatomy doses to machine errors and output calibration errors was also investigated. Results: For a Volumetric Modulated Arc Therapy (VMAT) plan evaluated on the Delta4 geometry, the conventional gamma passing rate was 99.6%. For a water-equivalent slab geometry, good agreements were found between dose profiles in film, treatment planning system, and Anatomy treatment plan dose measured modification and pencil beam calculations. Gamma passing rate for Anatomy treatment plan dose measured modification and pencil beam doses versus treatment planning system doses was 100%. However, gamma passing rate dropped to 97.2% and 96% for treatment plan dose measured modification and pencil beam calculations in inhomogeneous head & neck phantom, respectively. For the 10 patients’ quality assurance plans, good agreements were found between ion chamber measured doses and the planned ones (deviation: 0.09% ± 1.17%). The averaged gamma passing rate for conventional and Anatomy treatment plan dose measured modification and pencil beam gamma analyses in Delta4 geometry was 99.6% ± 0.89%, 98.54% ± 1.60%, and 98.95% ± 1.27%, respectively, higher than averaged gamma passing rate of 97.75% ± 1.23% and 93.04% ± 2.69% for treatment plan dose measured modification and pencil beam in patients’ geometries, respectively. Anatomy treatment plan dose measured modification dose profiles agreed well with those in treatment planning system for both Delta4 and patients’ geometries, while pencil beam doses demonstrated substantial disagreement in patients’ geometries when compared to treatment planning system doses. Both treatment planning system doses are sensitive to multileaf collimator and monitor unit (MU) errors for high and medium dose metrics but not sensitive to the gantry and collimator rotation error smaller than 3°. Conclusions: The new Delta4DVH Anatomy with treatment plan dose measured modification algorithm is a useful tool for the anatomy-based patient-specific quality assurance. Cautions should be taken when using pencil beam algorithm due to its limitations in handling heterogeneity and in high-dose gradient regions.

scholarly journals Implementation of a Compact Spot-Scanning Proton Therapy System in a GPU Monte Carlo Code to Support Clinical Routine

2020 ◽  
Vol 8 ◽  
Author(s):  
Jan Gajewski ◽  
Angelo Schiavi ◽  
Nils Krah ◽  
Gloria Vilches-Freixas ◽  
Antoni Rucinski ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Beam Model ◽  
Monte Carlo Code ◽  
Transverse Beam ◽  
Beam Shape ◽  
Clinical Criteria

The purpose of this work was to implement a fast Monte Carlo dose calculation tool, Fred, in the Maastro proton therapy center in Maastricht (Netherlands) to complement the clinical treatment planning system. Fred achieves high accuracy and computation speed by using physics models optimized for radiotherapy and extensive use of GPU technology for parallelization. We implemented the beam model of the Mevion S250i proton beam and validated it against data measured during commissioning and calculated with the clinical TPS. The beam exits the accelerator with a pristine energy of around 230 MeV and then travels through the dynamically extendable nozzle of the device. The nozzle contains the range modulation system and the multi-leaf collimator system named adaptive aperture. The latter trims the spots laterally over the 20 × 20 cm2 area at the isocenter plane. We use a single model to parameterize the longitudinal (energy and energy spread) and transverse (beam shape) phase space of the non-degraded beam in the default nozzle position. The range modulation plates and the adaptive aperture are simulated explicitly and moved in and out of the simulation geometry dynamically by Fred. Patient dose distributions recalculated with Fred were comparable with the TPS and met the clinical criteria. Calculation time was on the order of 10–15 min for typical patient cases, and future optimization of the simulation statistics is likely to improve this further. Already now, Fred is fast enough to be used as a tool for plan verification based on machine log files and daily (on-the-fly) dose recalculations in our facility.

Developing a Monte Carlo model for MEVION S250i with HYPERSCAN and Adaptive Aperture™ pencil beam scanning proton therapy system

2020 ◽  
pp. 1-8
Author(s):  
Bing-Hao Chiang ◽  
Austin Bunker ◽  
Hosang Jin ◽  
Salahuddin Ahmad ◽  
Yong Chen
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Monte Carlo Model ◽  
Particle Simulation ◽  
Planning System ◽  
Treatment Planning System ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Pencil Beam Scanning ◽  
Beam Characteristics

Abstract Aim: As the number of proton therapy facilities has steadily increased, the need for the tool to provide precise dose simulation for complicated clinical and research scenarios also increase. In this study, the treatment head of Mevion HYPERSCAN pencil beam scanning (PBS) proton therapy system including energy modulation system (EMS) and Adaptive Aperture™ (AA) was modelled using TOPAS (TOolkit for PArticle Simulation) Monte Carlo (MC) code and was validated during commissioning process. Materials and methods: The proton beam characteristics including integral depth doses (IDDs) of pristine Bragg peak and in-air beam spot sizes were simulated and compared with measured beam data. The lateral profiles, with and without AA, were also verified against calculation from treatment planning system (TPS). Results: All beam characteristics for IDDs and in-air spot size agreed well within 1 mm and 10% separately. The full width at half maximum and penumbra of lateral dose profile also agree well within 2 mm. Finding: The TOPAS MC simulation of the MEVION HYPERSCAN PBS proton therapy system has been modelled and validated; it could be a viable tool for research and verification of the proton treatment in the future.

Proton therapy dose distribution comparison between Monte Carlo and a treatment planning system for pediatric patients with ependymomaa)

2012 ◽  
Vol 39 (8) ◽  
pp. 4742-4747 ◽  
Author(s):  
Yingcui Jia ◽  
Chris Beltran ◽  
Daniel J. Indelicato ◽  
Stella Flampouri ◽  
Zuofeng Li ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Treatment Planning ◽  
Proton Therapy ◽  
Dose Distribution ◽  
Pediatric Patients ◽  
Planning System ◽  
Treatment Planning System

scholarly journals A complete workflow for utilizing Monte Carlo toolkits in clinical cases for a double-scattering proton therapy system

2018 ◽  
Vol 20 (1) ◽  
pp. 23-30
Author(s):  
Leland Muller ◽  
Michael Prusator ◽  
Salahuddin Ahmad ◽  
Yong Chen
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Double Scattering ◽  
Clinical Cases
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