Document Type : Conference Proceedings
Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Department of Medical Physics, Mashhad University of Medical Sciences, Mashhad, Iran
Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Reza Radiotherapy Oncology Center, Mashhad, Iran
Immunology Research Center, Bu-Ali Research Institute, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Introduction: To enhance radiation therapy efficiency it is crucial to implement an
individual-based treatment. The aim of present study was to identify the mechanism of intrinsic apoptosis pathway on radiosensitivity and normal tissue complications caused by the radiotherapy.
Materials and Methods: radiation-induced apoptosis in peripheral blood mononuclear cells derived from unselected breast cancer (BC) patients was examined using the relative quantitative RT-PCR. Expression levels of Bax, Bcl-2, and Bax/Bcl-2 ratio (as an in-vitro radiosensitivity index (RSI)) were examined in in-vitro irradiated (1 and 2 Gy) cells. All the patients received similar tangential irradiation of the whole breast and conventional fractionation and then, Clinical radiosensitivity (as a clinical radiosensitivity index) was determined using the acute reactions to radiotherapy of the skin according to RTOG score. All statistical analyses were performed using GraphPad Prism, version 7.01.
Results: The notable result was a significant correlation between dose-response curve slope (in-vitro RSI) and acute skin toxicity score following irradiation (clinical RSI).
Conclusion: These data suggest that Bax/Bcl-2 ratio determination before radiation therapy can be used as a potential biomarker to identify radiosensitive individuals. However, further studies are required to validate radiation-induced apoptotic biomarkers.