A kit for labeling of [188Re] human serum albumin microspheres for therapeutic use in nuclear medicine

Intra-arterial infusion of labeled particles is an effective method for local endoradiotherapy of tumors. In this study, we present an efficient method of radiolabeling biodegradable human serum albumin (HSA) microspheres with the short-lived beta-emitter 188Re using a simple and reliable kit. Up to now, it was not possible to label particles with more than 85-90% efficiency. Under optimized reaction conditions, we achieved nearly 100% uptake of 188Re. Using the proposed kit, we added tartrate solution and increased the pH from 2 to 4-5 after 1 h reaction time at 95 °C. The 188Re binding to the particles was found to be stable in vitro.