Speaker
Description
Ionizing radiation, a classified carcinogenic agent, necessitates the implementation of robust radiation protection policies, regulations, and tools to ensure staff safety. Staff members, who work with or in proximity to radiation sources, face the risk of tissue reactions (cataracts and erythema) and cancer induction. To prevent these risks and reduce the probability of cancer and hereditary effects, international and national regulations have been developed. This work is intended to evaluate the current reported radiation risks from various medical procedures and their implications on clinical practice. It will also examine the pivotal role of regulatory limits in determining annual dose limits based on risk models. The International Atomic Energy Agency (IAEA) recommends annual dose limits of 20 mSv per year in 1991 average of over 5 years, with a maximum of 50 mSv in any single year following the International Commission on Radiological Protection (ICRP) recommendation. In the United States, the nuclear regulatory commission (NRC) has set the annual dose limit of 50 mSv(50 rem) to an individual organ or tissue other than the lens of the eye, as determined by the deep-dose equivalent and the committed dose equivalent. These limits, which include a conservative buffer to account for uncertainties in radiation risk models, ensure that most workers receive far less than 20 mSv/year due to strict workplace controls, thereby keeping radiation exposure as low as reasonably achievable (ALARA) and preventing significant health risks. The 50 mSv/year limit is well below the dose needed to cause immediate harm (typically > 500 mSv in a short time). However, the study reviewed the current reported incidence, which showed that an increasing number of interventional radiology personnel exceed the dose limits, with many tissue reactions (cataracts) and cancer incidences reported. The variation in the annual dose limits is due to reports showing no strong excess cancer risk below ~100 mSv. Both dose limits provided adequate protection for the Staff, and the majority of medical practices ranged from 1.0 to 10.0 mSv per year. The improvement of the detector’s technology in medical imaging, with precise X-ray beam collimation and operators’ awareness, made the dose limit a ceiling rather than a target. In light of the Linear No-Threshold (LNT) model, which assumes any radiation dose can cause cancer, the future holds promise for further reduction of the annual dose based on the current reported risks and the availability of advanced imaging modalities that reduce the Staff's unnecessary exposure.
