Rhenium-188 Generator-Based Radiopharmaceuticals for Therapy

Abstract

Because of its on-demand availability from the 188W/188Re generator, broad interest has developed in the therapeutic use of 188Re for a wide variety of applications in nuclear medicine, oncology and interventional specialties. Rhenium-188 decays with emission of high energy β-particles (2.12 MeV, 71.1% and 1.965 MeV, 25.6%) and a gamma photon for imaging (155 keV, 15.1%). The 188W/188Re generator has an extended useful shelf-life of several months, which insures the continuous on demand radiopharmacy availability of 188Re. In addition to the ongoing development and evaluation of various 188Re-labeled agents, promising results using a variety of 188Re radiopharmaceuticals have been reported. The use of 188Re-HEDP has been evaluated in multiple trials as an effective agent for the treatment of metastatic bone pain. In addition, promising clinical data have been reported using trans arterial delivery of a variety of 188Re-labeled agents, including microspheres and Lipiodol analogues, for therapy of liver metastases and primary liver cancer. Use of 188Re-microspheres have also provided promising data for treatment of arthritis. Angioplasty balloons filled with liquids containing various 188Re-labeled agents for intravascular radiation therapy (IVRT) have been shown to effectively inhibit coronary and peripheral arterial restenosis. For this application, a variety of 188Re agents been evaluated, including perrhenate, DTPA and MAG3. These IVRT coronary studies have in particular demonstrated that event-free survival in patients is significantly longer compared to the placebo patients. Successful clinical applications have also been reported using 188Re-labeled patches for treatment of basal and squamous cell skin cancer, as an alternative to surgical removal. The expected further development, regulatory approval and commercialization of 188Re-labeled agents will add new capabilities for radionuclide therapy.