Applications to Patient-Specific Voxel Computational Phantoms in EGS Monte Carlo Codes for Radiation Treatment Involving Photons and Electrons

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Advance treatment techniques, such as IMRT and dynamic conformal arc delivery, are novel radiation treatment procedures at the forefront of accurate and precise radiotherapy. However, the risk of suboptimal treatment resulting in injury is far greater with these techniques due to their complexity. An in vivo quality assurance system is the most appropriate validation of the delivered dose to the patient from these techniques. The intent of this research is to propose an in vivo dosimetry quality assurance procedure using radiochromic film. This research proved that radiochromic in vivo dosimetry is a viable method of detecting spatial patient specific errors in radiotherapy; however, the process is time consuming and not sensitive enough for dosimetric errors associated with weight change. Although time consuming, in vivo radiochromic dosimetry is an attractive alternative for small cancer centers and developing countries without the large startup capital to acquire the electronic portal imaging device necessary for EPID in vivo dosimetry.

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PATIENT-SPECIFIC DOSIMETRY FOR PEDIATRIC IMAGING OF 99mTc-DIMERCAPTOSUCCINIC ACID WITH GATE MONTE CARLO CODE

Radiation Protection Dosimetry ◽

10.1093/rpd/ncx101 ◽

2017 ◽

Vol 178 (2) ◽

pp. 213-222 ◽

Cited By ~ 2

Author(s):

Mahmoud Bagheri ◽

Ali Asghar Parach ◽

Seid Kazem Razavi-Ratki ◽

Reza Nafisi-Moghadam ◽

Mohammad Ali Jelodari

Keyword(s):

Monte Carlo ◽

Dimercaptosuccinic Acid ◽

Patient Specific ◽

Monte Carlo Code ◽

Pediatric Imaging

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

International Journal of Particle Therapy ◽

10.14338/ijpt-19-00063.1 ◽

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.

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Simulation Study on Radiation Exposure of Emergency Medical Responders From Radioactively Contaminated Patients

10.21203/rs.3.rs-120848/v1 ◽

2020 ◽

Author(s):

Takakiyo Tsujiguchi ◽

Yoko Suzuki ◽

Mizuki Sakamoto ◽

Kazuki Narumi ◽

Katsuhiro Ito ◽

...

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Radiation Exposure ◽

Exposure Dose ◽

Radioactive Source ◽

Anxiety Reduction ◽

Radiation Doses ◽

Emergency Medical ◽

Radiation Emergency ◽

Computational Phantoms

Abstract Emergency medical responders (EMRs), who save victims in a radiation emergency, are at risk of radiation exposure. In this study, the exposure dose to EMRs assisting contaminated patients was estimated using a Monte Carlo simulation, and will produce data that contributes to EMR education and anxiety reduction. Using the Monte Carlo simulation, we estimated radiation doses for adult computational phantoms with radioactive contamination conditions radiation dosages were based on findings from previous studies. At the contamination condition corresponding to the typical upper limit of general GM survey meters, the radiation doses of EMRs were estimated to be less than μSv per hour. In case of a heavier contamination due to mishandling of an intense radioactive source with hundreds of GBq or more, their radiation doses would be close to 100 mSv per hour. The results have implied that the radiological accident with a highly radioactive source would expose EMR to the risk of significant radiation exposure exceeding the dose limit. It is thus crucial that the authority or other party who are responsible for the health of EMRs ensures that they shall have necessary education and training on the effective measures for protecting themselves from the possible, excessive radiation exposure.

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Benchmarking of Siemens Linac in Electron Modes: 8-14 MeV Electron Beams

Journal of Biomedical Physics and Engineering ◽

10.31661/jbpe.v8i2.806 ◽

2018 ◽

Vol 8 (2) ◽

Cited By ~ 1

Author(s):

H Dowlatabadi ◽

A A Mowlavi ◽

M Ghorbani ◽

S Mohammadi ◽

F Akbari

Keyword(s):

Monte Carlo ◽

Radiation Treatment ◽

Electron Beams ◽

Dose Profile ◽

Depth Dose ◽

Mcnpx Code ◽

Gamma Index ◽

Simulation Results ◽

Mc Simulation ◽

Good Agreement

Introduction: Radiation therapy using electron beams is a promising method due to its physical dose distribution. Monte Carlo (MC) code is the best and most accurate technique for forespeaking the distribution of dose in radiation treatment of patients.Materials and Methods: We report an MC simulation of a linac head and depth dose on central axis, along with profile calculations. The purpose of the present research is to carefully analyze the application of MC methods for the calculation of dosimetric parameters for electron beams with energies of 8–14 MeV at a Siemens Primus linac. The principal components of the linac head were simulated using MCNPX code for different applicators. Results: The consequences of measurements and simulations revealed a good agreement. Gamma index values were below 1 for most points, for all energy values and all applicators in percent depth dose and dose profile computations. A number of states exhibited rather large gamma indices; these points were located at the tail of the percent depth dose graph; these points were less used in in radiotherapy. In the dose profile graph, gamma indices of most parts were below 1. The discrepancies between the simulation results and measurements in terms of Zmax, R90, R80 and R50 were insignificant. The results of Monte Carlo simulations showed a good agreement with the measurements. Conclusion: The software can be used for simulating electron modes of a Siemens Primus linac when direct experimental measurements are not feasible.

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