Development of high-activity 252Cf sources for neutron brachytherapy.

The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using 252Cf medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing < or = 30 micrograms 252Cf in the form of a cermet wire of Cf2O3 in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop very compact, high-activity 252Cf neutron sources for use with remote afterloading equipment in order to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors. To date, the REDC has demonstrated that 252Cf loadings can be greatly increased in cermet wires and with much smaller diameters. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC.