What is a medical physicist?

The modern radiotherapy requires a medical physicist who optimizes treatment plans, assures delivered dose equal to prescription, and performs QA (quality assurance) of radiotherapy equipments. However, medical physicist has not been established as a medical profession in Japan mainly because importance of radiotherapy was not sufficiently recognized until recently. Between 2000 and 2004, several accidents of radiotherapy including hundreds of patients were found and these accidents were mainly caused by lack of QA. The necessity and importance of medical physicist were recognized by these accidents as well as by the advent of high-precision radiotherapy such as IMRT (intensity modulation radiation therapy). JRS (Japan Radiological Society) that certified medical physicists with the help of JSMP (Japan Society of Medical Physics), decided to extend eligibility in order to increase certified medical physicists rapidly in 2003. After the decision certified medical physicists were rapidly increased in number. The government supports this tendency to enact that certified medical physicists is necessary to reimbursement for high-precision therapy. It also started to supply grants for medical physics training in physical and health science graduate schools. In this program several universities have started medical physics course in their graduate schools. If these movements continue, medical physicist will be established as a medical profession in the near future. (author)