Are the risk and benefits of medical radiation exposure underestimated?

Radiation in medicine contributes significantly not only towards early detection of disease but also to reduce the incidence. Further, as radiological examinations are non-invasive, free of pain to the patient, and diagnosis is fast and reliable, their use is increasing. In turn, the population exposure to diagnostic and therapeutic ionizing radiation is likely to increase worldwide and about 14% from man-made sources. The unique features of radiation in medicine are that doses exposures range from up to few mGy for most diagnostic examinations to many tens of Gy for treatment of cancer. Although diagnostic procedures provide great benefits that the risk of developing stochastic effects resulting from their use is under active investigation. The issue is further challenged by recently reported radiobiological phenomena like adaptive response, bystander effects, low dose hypersensitivity, delayed genomic instability, hormesis and induced DNA repair. Thus, it appears that the effect of low dose radiation are rather complex on the effects of low dose radiation than predicted based on the high dose exposures. However, the effective doses of diagnostic X-ray examinations depend upon machine parameters, procedures and biological machinery of the individual determines the health effects. Data's obtained following exposures to very low dose and dose rate exposures received during imaging radiological procedures exposed in-vivo and therapeutic doses will be discussed in terms of the potential benefits and its associated risk. (author)