High Versus Low Dose Rate Intracavitary Irradiation of Carcinoma of the Uterine Cervix: A Preliminary Report

Remotely controlled intracavitary radiation therapy with high dose rate was introduced to eliminate the radiation hazard to the staff members.Nearly 70 sets of equipment had been installed in Japan by the end of October 1977.However, the biologic effect produced by the high dose rate is not quite clear, despite several reports on the clinical results from high versus low dose rate intracavitary irradiation for carcinoma of the uterine cervix.At the present time, various fractionation schedules are tested in the irradiation of carcinoma of the uterine cervix at various hospitals, such as 3 Gy (300 rad) 3 times a week, 5 Gy twice weekly, 6 Gy once a week and 10 Gy once a week.The total dose used varies between 28 and 36 Gy.However, the reports are difficult to compare as the clinical experience varies, as well as technique and dosimetry.Therefore it was considered motivated to compare high versus low dose rate intracavitary irradiation for carcinoma of the intact uterine cervix in a controlled series irradiated with uniform techniques. Materials and MethodsShimadzu Ralstron-20A was installed in Osaka University Hospital in 1974.