ABSTRACT
Dosimetry of normal organs, critical organs, and tumor tissues can be of help in patient selection and therapy planning for peptide radionuclide receptor therapy (PRRT). The experience acquired in the diagnosis of neuroendocrine tumors represented the basis for the development of PRRT, with a constantly increasing spectrum of applications. The use of 111In-peptides is limited to therapeutical trials with Octreoscan, due to its commercial availability. Red marrow toxicity represents the limiting factor in the majority of radionuclide therapies. For this reason, great efforts have been made to study proper models for red marrow dosimetry and tolerance. The radiopharmaceuticals used for PRRT have in common a high renal activity concentration, yielding to shift—or to expand—the general concern of toxicity from red marrow to kidneys. Dosimetry had the important task to evaluate the protective efficacy of different molecules and administration schemes, and to determine the possible increment of the cumulative activity to be administered in case of protection.
