Organ at risk dose calculation for left sided breast cancer treatments using intraoperative electron radiotherapy: A Monte Carlo-based feasibility study. (February 2020)

• Record Type: Journal Article
• Authors: Mansourian, Ghazale; Robatjazi, Mostafa; Baghani, Hamid Reza; Neshastehriz, Ali; Mahdavi, Seied Rabi; Koosha, Fereshteh
• Is Part Of: Applied radiation and isotopes. Volume 156(2020:Feb.)
• Publication Date: 2020-02
• Subjects: Monte Carlo simulation -- Organ at risk -- Breast cancer -- IOERT -- LIAC; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2019.108977
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: The present study aims to calculate the received dose by lungs and heart, as organs at risk (OAR), during intraoperative electron radiotherapy (IOERT) of left breast cancer at the presence and absence of shielding disk using Monte Carlo (MC) simulation. LIAC 12, a dedicated IOERT Linac, and an anthropomorphic phantom were considered in this study to simulate particle tracks of 6, 8, 10, and 12 MeV nominal electron energies using EGSnrc MC particle transport simulation code. The results showed that for increasing electron beam energies in the absence of shielding disk, left lung and heart dose would also be increasing so that, maximum left lung and heart dose respectively increases from 0.512 to 9.920 Gy and from 0 to 0.506 Gy with increment of electron energy from 6 to 12 MeV. Employing the shielding disk in 6 and 8 MeV energy can reduce the heart and left lung maximum dose to zero. On the other hand, this dose reduction at 10 and 12 MeV energy was respectively about 99% and 93.5% for heart and 99.9% and 92.9% for left lung. Right lung did not receive a remarkable dose both in presence and absence of shielding disk. From the results, it can be concluded that employing the shielding disk can effectively reduce the received dose to OARs. Highlights: The effect of shielding disk on OARs dose in the left breast IOERT was evaluated. Left lung, right lung, and heart were considered as OARs. OARs dose falls to zero by employing the shielding disk in energies up to 8 MeV. The OARs dose considerably decreases in the presence of shielding disk at 10 and 12 MeV energies.