The importance and unique aspects of radiation protection in medicine.

Radiation protection in medicine has unique aspects and is an essential element of medical practice. Medical uses of radiation occur throughout the world, from large cities to rural clinics. It has been estimated that the number of medical procedures using radiation grew from about 1.7 billion in 1980 to almost 4 billion in 2007. In spite of these large numbers, there are many parts of the world without adequate equipment, where the ability to perform additional medical procedures would likely result in a net benefit. Medicine accounts for more than 99.9% of the per caput effective dose from man-made sources. The goal in medical exposure is not to give the lowest dose, but to provide the correct dose to enable the practitioner to make the diagnosis or cure a tumour. Too little or too much dose is problematic and the risk of any given procedure ranges from negligible to potentially fatal. Radiation protection in medicine must deal with the issues of not having dose limits, purposely exposing sensitive subgroups, and purposely using doses that could cause deterministic effects. Radiation accidents involving medical uses have accounted for more acute radiation deaths than from any other source including Chernobyl. Many physicians have little or no training in radiation protection, and many have no qualified medical physics support. In many countries, medical radiation devices and uses are only minimally regulated and the rapidly evolving technology is a challenge. Medicine also accounts for the largest number of occupationally exposed workers and collective dose.