External beam pelvic radiotherapy plus intraperitoneal radioactive chronic phosphate in early stage ovarian cancer: A toxic combination: A national cancer institute of Canada clinical trials group report☆

Abstract As part of a randomized trial evaluating several treatment programs in the management of poor prognosis, early stage ovarian cancer, 53 patients were randomized to receive a combination of pelvic external beam radiation, 4000 rad plus 10–20 millicuries of radioactive chromic phosphate given intraperitoneally. Only 35 patients (66%) actually received the chromic phosphate. The other 18 did not enter this phase of treatment for a variety of reasons documented in this report. Ten (29%) of the 35 patients receiving the full course of treatment had significant long term side effects with the median time to onset of symptom being 9 months after the chronic phosphate was given. There were no treatment-related deaths. The complications could not be related to the dose of the isotope, the technique of administration, nor any other definable predisposing factors. This combination is not recommended for further study.