scholarly journals Estimating Radiotherapy-Induced Secondary Cancer Risk Arising from Brain Irradiation at High Energy: A Monte Carlo Study

2021 ◽  
Author(s):  
Soheil Elmtalab ◽  
Amir Hossein Karimi ◽  
Fardin Samadi Khoshe Mehr ◽  
Hamed Zamani ◽  
Iraj Abedi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Cancer Risk ◽  
Radiation Risk ◽  
Monte Carlo Study ◽  
High Energy ◽  
Whole Body ◽  
National Council ◽  
Secondary Cancer ◽  
Photon Dose ◽  
Secondary Cancer Risk

Background: The present study aims to determine the whole-body out-of-field photon dose equivalents of high-energy conventional radiation therapy treatment. Also, it is tried to estimate the probability of fatal secondary cancer risk for the susceptible organs using a Monte Carlo (MC) code. Materials and methods: An Monte Carlo N-Particle eXtended (MCNPX)-based model of 18-MV Medical Linear Accelerator (LINAC) was created to calculate the out-of-field photon dose equivalent at the locations of fascinating organs in the mathematical female Medical Internal Radiation Dosimetry (MIRD) phantom. Then, the secondary malignancies risk was estimated based on out-of-field doses and radiation risk coefficients according to the National Council of Radiation Protection and Measurements (NCRP). Results: The average photon equivalent dose in out-of-field organs was about 3.25 mSv/Gy, ranging from 0.23 to 37.2 mSv/Gy, respectively, for the organs far from the Planning Target Volume (PTV) (Eyes) and those close to the treatment field (rectum). The entire secondary cancer risk for the 60 Gy prescribed dose to isocenter was obtained as 2.9987%. Here, the maximum doses among off-field organs were related to stomach (0.0805%), lung (0.0601%), and thyroid (0.0404%). Conclusion: Regarding the estimated values for the probability of secondary cancer risk, it is suggested to perform a long-term follow-up of brain cancer patients regarding the prevalence of thyroid, stomach, and lung cancer after completing the treatment course.

Monte Carlo simulation of non-target organ doses and radiation-induced secondary cancer risk in Tanzania from radiotherapy of nasopharyngeal by using Co-60 source

2020 ◽  
Vol 171 ◽  
pp. 108731 ◽  
Author(s):  
Suleiman Ameir Suleiman ◽  
Salum Kombo Salum ◽  
Ali Othman Masoud ◽  
Jumaa Dachi Kisukari ◽  
Mohamed Mazunga ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Cancer Risk ◽  
Target Organ ◽  
Secondary Cancer ◽  
Organ Doses ◽  
Secondary Cancer Risk ◽  
Radiation Induced

160 The impact of dose escalation on secondary cancer risk after radiotherapy of prostate cancer

2006 ◽  
Vol 78 ◽  
pp. S54
Author(s):  
U. Schneider ◽  
A. Lomax ◽  
J. Besserer ◽  
N. Lombriser ◽  
P. Pemler ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Risk ◽  
Dose Escalation ◽  
Secondary Cancer ◽  
Secondary Cancer Risk ◽  
The Impact

Fetal dose from proton pencil beam scanning craniospinal irradiation during pregnancy: a Monte Carlo study

2022 ◽  
Author(s):  
Yeon Soo Yeom ◽  
Keith Tchadwick Griffin ◽  
Matthew M Mille ◽  
Choonik Lee ◽  
Shannon O'Reilly ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ct Scan ◽  
Monte Carlo Study ◽  
Whole Body ◽  
Pencil Beam ◽  
Pencil Beam Scanning ◽  
Fetal Organ ◽  
Organ Tissue ◽  
Planning Ct ◽  
Fetal Dose

Abstract Objective: We conducted a Monte Carlo study to comprehensively investigate the fetal dose resulting from proton pencil beam scanning (PBS) craniospinal irradiation (CSI) during pregnancy. Approach: The gestational-age dependent pregnant phantom series developed at the University of Florida (UF) were converted into DICOM-RT format (CT images and structures) and imported into a treatment planning system (TPS) (Eclipse v15.6) commissioned to a IBA PBS nozzle. A proton PBS CSI plan (prescribed dose: 36 Gy) was created on the phantoms. The TOPAS MC code was used to simulate the proton PBS CSI on the phantoms, for which MC beam properties at the nozzle exit (spot size, spot divergence, mean energy, and energy spread) were matched to IBA PBS nozzle beam measurement data. We calculated mean absorbed doses for 28 organs and tissues and whole body of the fetus at eight gestational ages (8, 10, 15, 20, 25, 30, 35, and 38 weeks). For contextual purposes, the fetal organ/tissue doses from the treatment planning CT scan of the mother’s head and torso were estimated using the National Cancer Institute dosimetry system for CT (NCICT, Version 3) considering a low-dose CT protocol (CTDIvol: 8.97 mGy). Main Results: The majority of the fetal organ/tissue doses from the proton PBS CSI treatment fell within a range of 3 to 6 mGy. The fetal organ/tissue doses for the 38-week phantom showed the largest variation with the doses ranging from 2.9 mGy (adrenals) to 8.2 mGy (eye lenses) while the smallest variation ranging from 3.2 mGy (oesophagus) to 4.4 mGy (brain) was observed for the doses for the 20-week phantom. The fetal whole-body dose ranged from 3.7 mGy (25 weeks) to 5.8 mGy (8 weeks). Most of the fetal doses from the planning CT scan fell within a range of 7 to 13 mGy, approximately 2-to-9 times lower than the fetal dose equivalents of the proton PBS CSI treatment (assuming a quality factor of 7). Significance: The fetal organ/tissue doses observed in the present work will be useful for one of the first clinically informative predictions on the magnitude of fetal dose during proton PBS CSI during pregnancy.

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