Abstract
Conventional nuclear medicine dosimetry involves specifying individual organ doses. The difficulties that can arise with this approach to radiation dosimetry are discussed. An alternative scheme is described that is based on the ICRP effective dose equivalent, HE, and which is a direct estimate of the average radiation risk to the patient. The mean value of HE for seven common 99mTc nuclear medicine procedures is 0.46 rem and the average radiation risk from this level of exposure is estimated to be comparable to the risk from smoking ~ 28 packs of cigarettes or driving ~ 1,300 miles.