High-dose-rate endorectal brachytherapy for locally advanced rectal cancer in previously irradiated patients

Abstract

Preoperative high-dose-rate (HDR) endorectal brachytherapy is well tolerated among patients with locally advanced rectal cancer. However, these studies excluded patients who previously received pelvic radiation therapy (RT). Because a favorable toxicity profile has been published for HDR endorectal brachytherapy, we evaluated this technique in patients who have previously received pelvic irradiation. We included patients who had received pelvic irradiation for a previous pelvic malignancy and later received preoperative HDR endorectal brachytherapy for rectal cancer. Brachytherapy was delivered to a total dose of 26 Gy in 4 consecutive daily 6.5 Gy fractions. We evaluated 10 patients who previously received pelvic external beam radiation therapy (EBRT) alone (n=6), EBRT and brachytherapy (n=2), or brachytherapy alone (n=2). The median interval between the initial course of RT and endorectal brachytherapy was approximately 11 years (range, 1-19 years). Two patients experienced a complete pathologic response while 1 patient had a near complete pathologic response. No acute grade ≥3 toxicity was observed. No intraoperative or postoperative surgical complications were observed. Preoperative HDR endorectal brachytherapy is an alternative to EBRT for patients with locally advanced rectal cancer who have previously received pelvic RT.