Abstract ID: 106 Performance evaluation of two dedicated radioprotective disks in breast intraoperative electron radiotherapy

• DOI: 10.1016/j.ejmp.2017.09.058
• Publication Date: 2017-10-14T00:16:38Z
• Authors: Shiva Ghasemi; Hamid Reza Baghani; Seyed Rabi Mahdavi; Mohsen Bakhshandeh; Nahid Nafissi
• Keywords: Intraoperative radiotherapy

The aim of breast intraoperative electron radiotherapy is to deliver the prescribed dose to the tumor bed during surgery. In this method, sensitive organs such as pectoral muscles, heart and lungs may be exposed to radiation. Therefore, a radioprotective disk is commonly used to protect the underlying healthy tissues. In this study, the performance of two employed radioprotective disks for breast intraoperative radiotherapy in terms of transmission factor (TF) and backscatter factor (BSF) were compared and the optimum disk was introduced. TF and BSF of the disks understudy, first disk consisted of PTFE-stainless steel and the second one consisted of PMMA-Copper, were determined through irradiating the disks by LIAC mobile accelerator inside the water phantom and Advanced Markus ion chamber dosimetry. According to the obtained results, the BSF values of second disk in energies of 6, 8, 10 and 12 MeV was 4.5%, 2.8%, 3.8% and 2.9% lower than the first disk, respectively. In addition, the TF values of second disk in energies of 6, 8, 10 and 12 MeV was also 100%, 20%, 60% and 71% lower than the first one, respectively. Based on the results, it can be concluded that the second radioprotective disk (consisted of PMMA and Copper) has the better protecting performance and in addition to the dose uniformity inside the tumor bed, will minimize the received dose to the organs at risk.