Radiation dosimetry in nuclear medicine - recent developments

This paper reviews developments in radiation dosimetry in Nuclear Medicine over the past few years. The practical scope of the Medical Internal Radiation Dose (MIRD) Committee's Schema for dose determination has been extended by the development of more realistic mathematical models of the human body, together with the improvement in basic physical data used in dose calculations. Apart from the use of the Adult Human Phantom as the basis for dose determination, models have been developed for the estimation of doses to children and to the developing foetus. The Schema has been extended to permit calculations of the dose to dynamic organs, particularly the bladder. The principle of Monte Carlo photon history simulation, which forms the basis of much of the MIRD Schema's published data, has been used at the Australian Atomic Energy Commission for the determination of complete photon dose distributions. These are more meaningful in many cases than the average doses determined by the absorbed fraction method. (author)