Hypofractionated Extracranial Stereotactic Radiotherapy Boost for Gynecologic Tumors: A Promising Alternative to High-Dose Rate Brachytherapy

Abstract

The purpose of this study is to report toxicity and outcome results in patients with gynaecological tumours treated with a final boost using extra-cranial stereotactic radiotherapy (SRT) with a linac-based micro-multileaf collimator technique as an alternative to high-dose rate brachytherapy (HDR-BT). Since January 2002, 26 patients with either endometrial (n = 17) or cervical (n = 9) cancer were treated according to this protocol: 45–50.4 Gy external radiotherapy (RT) to the pelvic ± para-aortic regions followed by a final SRT boost of 2 × 7 Gy to the vaginal vault (4–7 day interval between fractions). Median age was 62 years (37–74 range). Fifteen patients were diagnosed with adenocarcinoma, 7 with squamous-cell carcinoma, and 4 with sarcoma. FIGO stage I (n = 17), stage II (n = 7), and stage III (n = 2). Toxicity was scored according to RTOG/EORTC criteria. No severe (>grade-3) acute urinary or low-gastrointestinal (GI) toxicity was observed during treatment and up to 3 months after treatment completion. Moderate (grade ≤ 3) acute urinary or low-GI toxicity was observed in 23% and 35% of patients, respectively. After a median follow-up of 47 months (4–77, range), late urinary, low-GI, and sexual ≥grade-2 (worst score) has been reported in 4%, 12% and 29.4% of patients, respectively. The 3-year loco-regional failure-free and overall survival rates were 96% and 95%, respectively. Preliminary results on feasibility, tolerance, and outcome with SRT are encouraging and may be considered a sound alternative to HDR-BT for gynecologic tumors.