Preoperative Intrauterine Irradiation of Endometrial Carcinoma Stage I: A Clinical and Radiographic Evaluation of the Bulb Technique

Abstract

In a series of 146 cases of endometrial carcinoma stage I an afterloading technique using high dose-rate cobalt-60 sources has been evaluated for preoperative intracavitary irradiation. The uterine cavities were visualized by hysterograms and the target volumes were calculated. Absorbed doses were estimated at the surface of the target volume and within the uterine cavity. Surgery was performed six weeks after radiotherapy and the operative specimens were examined by a whole-organ sectioning technique. The frequency of residual carcinoma was assessed in relation to reference doses, minimum doses in the target and the position of the treatment catheter. The dose per fraction at the reference point, the minimum absorbed dose at the anterior surface of the target, the anterior-posterior diameter of the target volume and the position of the treatment catheter within the uterine cavity were found to be significant for tumor eradication. The irradiation technique and the histopathologic findings with reference to the operative specimen were significant for the rate of vaginal metastases but not for tumor recurrences at other sites. Radiation reactions involving the urogenital organs were few (4.8%). The most serious radiation reaction was obstruction of the small bowel (5.5%). The absorbed dose per fraction was the most important single risk factor for this complication.