Concurrent chemoradiotherapy using high-dose-rate intracavitary brachytherapy with a modified dose schedule: Retrospective analysis of a single institutional experience

Abstract

15019 Background: The purpose of this study was to assess the effectiveness of concurrent chemoradiotherapy (CCRT) using high-dose-rate intracavitary brachytherapy (HDR-ICBT) with a dose schedule modified from the American Brachytherapy Society (ABS) recommendation. Methods: 68 consecutive patients (IB2: 3, IIA: 2, IIB: 32, and IIIB: 31) with cervical squamous cell carcinoma consecutively treated with CCRT using HDR-ICBT were retrospectively analyzed. Patients with para-aortic lymphadenopathy (greater than 10mm in minimum diameter assessed by CT) were excluded. The median tumor size (assessed by MRI) was 60mm (range: 40–86mm). Cisplatin (20 mg/m2/day) was concurrently administered with radiotherapy (RT) for 5 days at 21-day intervals for a median of 2 courses (range: 1–5). The planned RT schedule consisted of pelvic external beam RT (EBRT) with 40Gy/20 fractions followed by HDR-ICBT with 18Gy/3 fractions and pelvic EBRT with 10Gy/5 fractions using a midline block (MB). The cumulative biologically effective dose (BED) at point A of this schedule was 77Gy10. 60 patients (88%) were treated with this schedule. In the remaining 8 patients, pelvic EBRT was delivered without MB (up to 50Gy), and/or additional HDR-ICBT (up to 24Gy) was given. The actual BED for all 68 patients thus ranged from 77 to 89 Gy10. Median follow-up of the surviving 54 patients was 46 months (range: 8–91 months). Late complications were graded by the RTOG/EORTC criteria. Results: The actuarial overall survival rate, disease-free survival rate, and pelvic control rate at 4 years were 78% (95% CI, 68–90%), 74% (95% CI, 63–85%), and 90% (95% CI, 83–97%), respectively. Only one patient suffered a grade 3 complication (enterocolitis). The actuarial late complication (Grade 1or higher) rates at 4 years were 12% (95% CI, 3–20%) for proctitis, 2% (95% CI, 0–5%) for cystitis, and 21% (95% CI, 10–33%) for enterocolitis. Conclusions: This retrospective analysis suggests that CCRT using HDR-ICBT with a modified dose schedule was able to achieve favorable pelvic disease control without severe late complications for patients with cervical cancer. No significant financial relationships to disclose.