Radiation dose calculations using S values of a reference man can intr
oduce substantial errors for individual patients. We found that all no
n target sources can be included in the remainder of the body estimate
for therapeutic radionuclides. A practical method to derive organ S v
alues based on MIRD data and the mass of the organ and total body of i
ndividual patients is proposed. (C) 1997 Elsevier Science Inc.