Revisit the Effects of Low Dose Radiation in Diagnosis and Therapy

Since Wilhelm Conrad Rontgen discovered X-rays in 1895 followed by Big-Bang breakthrough of researches in modern physics, radiation has become part of human life more than one century. For common populations, the medical radiation is probably the most well-known application of this basic physic research. As a powerful weapon in clinical, radiation has been widely used in diagnosis and therapy. Nowadays, medical radiation by external beams and nuclear medicine account for approximately 50% of annual radiation exposure in United States (National Council on Radiation Protection and Measurements, NRCP Report No. 160, 2009). General speaking, the dosage of medical radiation is believed to be ablated to avoid side effects. However, accumulated literatures concern the abused application of radiation diagnosis, especially the Computed Tomography (CT) scan that may cause unexpected side effects [1]. Additionally, the intensity-modulated radiotherapy (IMRT) originally designed for delivery of precise doses to tumor with minimized dose to surrounding tissues has been reported to increase the probability of side effects and secondary cancer induction, although such a risk may depend on tissue types and patient selection (such as age at exposure) [2]. Therefore, the effects of low dose radiation should not be overlooked for diagnosis and therapy.