Alpha Radionuclide Therapy: Principles and Applications to NETs

Abstract

Radionuclide therapy of neuroendocrine tumors (NETs) including carcinoids, pheochromocytomas, and paragangliomas has an established role. Until recently, therapeutic radiopharmaceuticals for NETs consisted mainly of I-131 MIBG, Y-90/Lu-177/In-111 somatostatin analogs, and bone-seeking radiopharmaceuticals such as Sr-89 and Sm-153. The latter reagents are beta emitters or in the case of In-111, an auger emitter. Alpha emitters have significantly more potent effects and various advantages compared to beta emitters. Although a limited number of studies have been performed with alpha emitters, only a few have targeted NETs. In this presentation, we discuss the rationale for alpha emitters, review existing clinical use of alpha emitters (Bi-213, Ac-225, Pb-212, At-211, Ra-223) in various clinical applications (non-NET), and review existing literature on the preclinical and clinical use of alpha emitters in NETs.