Clinical trial of 252Cf neutron brachytherapy vs. conventional radiotherapy for advanced cervical cancer

252Cf, a neutron emitting radioactive transplutonium isotope, was tested for its efficacy against advanced bulky Stage III-IV cancers of the cervix in a clinical trial at the University of Kentucky Medical Center. Eighty-two patients were treated during 1976-1979 and followed for 5-year survival and tumor control. Three different treatment methods went on sequentially and concurrently, that is, (a) conventional whole pelvis photon with delayed 137Cs implants, (b) conventional photon therapy with delayed 252Cf implants, and (c) 252Cf implants ("early") preceding photon therapy. There were 12% 5-year survival for Stage IIIB cancers by conventional therapy, and 15% by delayed 252Cf implant therapy. For early 252Cf implant therapy there were 54% 5-year survivals with 4% complications and 65% 5-year local control, but distant metastases became a prominent delayed failure pattern.