High-dose rate intracavitary irradiation using linear source arrangement for squamous cell carcinoma of the uterine cervix

Purpose: To evaluate the results of fractionated high-dose-rate (HDR) intracavitary irradiation using a linear source arrangement (LSA) without vaginal ovoids for patients with squamous cell carcinoma of the uterine cervix. Methods and Materials: From 1980 to 1990, 236 patients with squamous cell carcinoma received external beam therapy (EBT) followed by fractionated HDR intracavitary irradiation using LSA (HDR-LSA). The initial FIGO stage was I, II, and III for 19, 71, and 146 patients respectively. Forty Gy in 20 fractions (40 Gy/20 Fr) were delivered to the whole pelvis and additional 10 Gy/5 Fr to the center shielding field with parallel opposed ports. The HDR-LSA dose was 30 Gy/6 Fr or 35 Gy/7 Fr at Manchester's point A giving two fractions per week. During the intracavitary irradiation, patients were treated in the out-patient clinic. A vaginal plastic applicator was inserted with lubricating gel without spinal or general anesthesia and gauze packing. Results: Pelvic failure rate was 10.5% for stage I, 12.7% for stage II, and 35.6% for stage III. Cause-specific 5-year survival rates were 69.1% for stage I, 77.1 % for stage II, and 50.1 % for stage III, respectively. The low survival for stage I disease was suggested to be due to selection bias. In multivariant analyses, stage (stage I+II vs. III, p=0.0003), pre-treatment serum hemoglobin level (p=0.0021), pre-treatment serum total protein level (p=0.0028), and total treatment time (p=0.0035) were significantly associated with cause-specific survival. The rate of late severe complications was 2.1% for rectum, 1.2% for small intestine, and 1.3 % for bladder. Conclusions: The LSA-HDR method following EBT is a safe and effective technique for the majority of patients. Reproducibility of dose distribution and the easiness of the insertion for the patients are suitable for multi-fractionated schedule required in HDR treatment. The benefit of the LSA, compared to the arrangement using a tandem and ovoids, should be reappraised in the light of patient comfort, biological importance of multi-fractionation, and the compatible treatment results of the present study