High-dose-rate versus low-dose-rate intracavitary therapy for carcinoma of the uterine cervix: a randomized trial

BACKGROUND: This was a prospective randomized clinical trial undertaken at our institution to compare low-dose-rate (LDR) intracavitary radiation therapy versus high-dose-rate (HDR) intracavitary radiation therapy for the treatment of cervical carcinoma. METHODS: From January 1984 to December 1997, a total of 132 patients with Stage II or IIIB of invasive carcinoma of the uterine cervix were entered into this randomized study. Treatment arm by HDR or LDR was allocated according to the month of each patient's birth. External irradiation consisted of whole pelvis irradiation and pelvic irradiation. Doses of external irradiation for both groups were identical. The authors used 0.588 as the conversion factor of total intracavitary dose from LDR to HDR. RESULTS: The 5-year disease specific survival rates of Stage II and III patients treated with HDR were 69% and 51% whereas those with LDR were 87% and 60%, respectively. The 5-year pelvic recurrence free survival rates of Stage II and III patients treated with HDR were 89% and 73% whereas those with LDR were 100% and 70%, respectively. There was no significant difference in disease specific survival or pelvic recurrence free survival rates between HDR and LDR. The actuarial complication rate (Radiation Therapy Oncology Group Grade 3, 4, or 5) at 5 years was 10% in the HDR group and 13% in the LDR group, and the difference between the HDR and LDR groups was not statistically significant. CONCLUSIONS: The pelvic control or actuarial complication rates were comparable between HDR and LDR treatment. The difference between the disease specific survival rates for HDR and LDR was not statistically significant for Stage II or III, although in Stage II, patients treated with LDR appeared to have a better survival rate than those treated with HDR.