High-dose-rate afterloading intraluminal brachytherapy for advanced inoperable rectal carcinoma

High-dose-rate (HDR) intraluminal brachytherapy for advanced or inoperable tumors of the rectum has been used both palliatively and to dose escalate after chemoradiation for curative treatment.

Between 1993 and 2007, 79 patients were treated with HDR afterloading brachytherapy for rectal cancer; 70 patients had adenocarcinoma of the rectum; and 9 patients had squamous cell carcinoma of the anal canal. Fifty-two patients had localized disease but were unfit for major surgery and received radiotherapy with radical intent. Twenty-seven patients with advanced or metastatic disease received palliative treatment. The median age was 82 years (range, 33-97). Radical treatment comprised either chemoradiation followed by intraluminal brachytherapy delivering 12 Gy at 1 cm in two fractions or radical monotherapy delivering up to 36 Gy at 1 cm in six fractions two to three times weekly. Palliative HDR brachytherapy schedules were predominantly 10 Gy at 1 cm single dose.

Objective local tumor response was seen in 41 of 48 assessable patients (85%); of whom, 28 patients (58%) had a complete response and 13 (27%) had a partial response. The most common symptom was rectal bleeding, which was controlled with a complete response rate of 63%. The median duration of the symptom response was 3 months (range, 1-73), and the median survival of the palliative patients was 6 months (range, 1 week-37 months). The median survival for patients treated with radical intent was 18.5 months (range, 2-119). Six patients reported late toxicity with three cases of rectal ulcer, two strictures, and one fistula.

Intraluminal HDR brachytherapy is effective as local treatment in both the radical and palliative setting, with high tumor and symptom response rates, and acceptable late toxicity.