[Occupational exposure to radiation].

Since the discovery of X-rays , overexposures and radiation injuries have been reported in both patients and persons exposed in the course of their professional duties. Each year, more than 2,500 million diagnostic radiological examinations, 32 million nuclear medicine examinations or treatment procedures and 5.5 million radiotherapy sessions are performed worldwide. Despite all precautions, avoidable incidents and accidents occur throughout the world every year , albeit with low frequency. Whereas diagnostic radiology is generally safe for patients and staff, interventional procedures (e.g. coronary artery dilatations) involve the risks of occupational overexposure and of skin injuries to patients. In nuclear medicine, radiation protection is focused on the introduction of new procedures with beta-emitters, for example. The increasing frequency of positron emission tomography (PET) requires a special focus on shielding measures. In radiotherapy, occupational overexposure caused by malfunctions and accidents is relatively rare.