Lutetium-177 (<sup>177</sup>Lu) is a rare earth metal in the lanthanides series which decays by beta emission with a half life of 6.647 days to three excited states and the ground state of<sup>177</sup>Hf. When <sup>177</sup>Lu is produced by neutron capture in 176Lu, inevitably an admixture is formed of the long-lived isomer <sup>177m</sup>Lu. As its half-life of 160.4 days is so much longer than that of <sup>177</sup>Lu, concerns are raised on its possible enhancement in radiation dose to the patient treated with <sup>177</sup>Lu-DOTA-octreotate. This report evaluates this possible enhancement of the absorbed dose, based on the published pharmacokinetic profile of <sup>177</sup>Lu-DOTA-octreotate and assuming an admixture of 1 kBq <sup>177m</sup>Lu /MBq <sup>177</sup>Lu (0.1%).

177Lu-DOTA-octreotate, 177mLu, Isomer, Lutetium-<sup>177</sup>, Meta-Stable, Pharmacokinetic
Current Radiopharmaceuticals

Konijnenberg, M. (2015). Consequences of meta-stable 177mLu admixture in 177Lu for patient dosimetry. Current Radiopharmaceuticals, 8(2), 145–149. Retrieved from