Radiation-induced Bystander Effect and Its Possible Countermeasures

Abstract

Ionizing radiation has been indispensable to medical diagnosis. In cancer, radiation therapy or radiotherapy (RT) offers patients a better chance of survival. It destroys cancer by depositing high-energy radiation on the cancer tissues, though it may directly damage a few normal cells. Therefore, the total radiation dose is administered in fractionated modalities over weeks or months. However, experimental evidence indicates that the irradiated cancer cells subsequently release cytokines in the blood that enter into nearby unirradiated nuclei/cells through several signaling pathways and cause radiation-induced bystander effects (RIBEs) such as DNA damage, chromosomal instability, mutation, and apoptosis in them as side effects of RT. Recently, many combined therapeutic protocols consisting of a few natural and synthetic products have been proposed to minimize RIBEs. This article reviews the present understanding of RIBEs and their possible countermeasures. Besides, a new protocol of combined therapy of nanoparticle-based ion treatment (NIT) and RT to minimize RIBEs has been proposed.