Abstract
Peptide-receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs such as octreotide is an effective therapy against neuroendocrine tumors. Other radiolabeled peptides and antibody fragments are under investigation. Most of these compounds are cleared through the kidneys and reabsorbed and partially retained in the proximal tubules, causing dose-limiting nephrotoxicity. An overview of renal handling of radiolabeled peptides and resulting nephrotoxicity is presented, and strategies to reduce nephrotoxicity are discussed. Modification of size, charge, or structure of radiolabeled peptides can alter glomerular filtration and tubular reabsorption. Coinfusion of competitive inhibitors of reabsorption also interferes with the interaction of peptides with renal endocytic receptors; coinfusion of basic amino acids is currently used for kidney protection in clinical PRRT. Furthermore, nephrotoxicity may be reduced by dose fractionation, use of radioprotectors, or use of mitigating agents. Decreasing the risk of nephrotoxicity allows for administration of higher radiation doses, increasing the effectiveness of PRRT.
Footnotes
-
COPYRIGHT © 2010 by the Society of Nuclear Medicine, Inc.
-
Learning Objectives: On successful completion of this activity, participants should be able to describe (1) mechanisms of renal accumulation of radiolabeled peptides, proteins, and antibody fragments; (2) different techniques to reduce kidney damage in peptide-receptor radionuclide therapy and antibody fragment radioimmunotherapy; and (3) factors determining the risk of nephrotoxicity in radionuclide therapies.
-
Financial Disclosure: The authors of this article have indicated no relevant relationships that could be perceived as a real or apparent conflict of interest.
-
CME Credit: SNM is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing education for physicians. SNM designates each JNM continuing education article for a maximum of 1.0 AMA PRA Category 1 Credit. Physicians should claim only credit commensurate with the extent of their participation in the activity.
-
For CE credit, participants can access this activity through the SNM Web site (http://www.snm.org/ce_online) through July 2011.