Radiogenic risks associated with techniques used in bone status evaluation
Although diagnostic X-ray examinations provide great benefits, their use involves the potential risk of carcinogenesis. Estimation of cancer risks associated with the radiation exposure from diagnostic X-rays is possible by using radiation dose data and appropriate risk coefficients provided by scientific committees. Risk estimation is based on the linear no-threshold (LNT) model. LNT presupposes that there is a linear relationship between radiation dose and health risk at all dose levels. The risk estimate based on the LNT model is a useful tool not only for justification of medical exposures but also for comparison with other risks. The Biological Effects of Ionizing Radiation Committee VII (BEIR VII) recently estimated sex- and age-specific risk factors attributable to radiation [57]. Of note, however, is that patient and occupational effective doses from techniques used in clinical practice for evaluation of bone status and potential radiogenic risks are very small compared with the expected benefits [58].
Assessment of radiogenic risk from diagnostic X-ray examinations has several limitations. There is debate regarding whether low-level radiation provides a significantly increased risk of developing cancer. The biological effects of diagnostic radiation on humans have not been studied directly. Current information is based on studies of populations such as atomic bomb survivors, radiation workers and patients treated with radiation. Most individuals in these cohorts received effective doses that were much larger than the doses from diagnostic X-ray examinations. However, recent studies show a significant increase in cancer risk in a group of atomic bomb survivors who received doses of radiation comparable to those currently involved in diagnostic radiology [48, 59]. The potential risk to an individual associated with techniques used for the assessment of bone status is very small because radiation doses are low. Despite uncertainty about the true risks of exposure to radiation levels used in these techniques, radiation protection principles must be applied in everyday clinical practice.