Preoperative high dose rate brachytherapy for rectal cancer

The following grade 2 toxicity events were reported in patients treated by a preoperative high dose rate (HDR) brachytherapy boost and external beam radiotherapy (EBRT) with concomitant chemotherapy in a randomised controlled trial (RCT) of 243 patients: 'skin' (20%), diarrhoea (19%), proctitis (18%), nausea (6%), dysuria (6%), vomiting (2%), stomatitis (2%), and neutropenia (1%). Similar rates were seen in patients treated by preoperative EBRT alone with concomitant chemotherapy. Grade 3 acute proctitis was reported in 1% (2/285) of patients in a case series of 285 patients treated by preoperative HDR brachytherapy. Rectal pain was reported in 71% (12/17) of patients treated by preoperative HDR brachytherapy in a non‑randomised comparative study of 36 patients.

Wound infection was reported in 15% (16/106) of patients treated by a preoperative HDR brachytherapy boost and EBRT compared against 11% (12/109) of patients treated by preoperative EBRT alone in the RCT of 243 patients. 'Infection' was reported in 9% (30/318), 8% (26/318) and 6% (20/318) of patients treated by preoperative HDR brachytherapy, by EBRT or by surgery alone, respectively, in the non‑randomised comparative study of 954 patients (p=0.2). In the same study wound infection was reported in 9% (29/318), 12% (39/318) and 6% (19/318) of patients treated by preoperative HDR brachytherapy, by EBRT or by surgery alone, respectively (p=0.25), and intra‑abdominal infection was reported in 4% (12/318), 3% (8/318) and 3% (9/318) of patients, respectively (p=0.4). Pelvic sepsis and wound sepsis were each reported in 4% (4/106) of patients in a case series of 106 patients.

Wound dehiscence was reported in 3% (9/318), 3% (8/318) and 2% (5/318) of patients treated by preoperative HDR brachytherapy, by EBRT or by surgery alone, respectively, in the non‑randomised comparative study of 954 patients (p=0.4). Anastomotic dehiscence was reported in 4% (13/318), 6% (20/318) and 4% (13/318) of patients treated by preoperative HDR brachytherapy, by EBRT or by surgery alone, respectively, in the non‑randomised comparative study (p=0.2) and in 4% (4/106) of patients in the case series of 106 patients.

Fistula was reported in less than 1% (1/106) of patients treated by a preoperative HDR brachytherapy boost and EBRT, and in 2% (2/109) of patients treated by preoperative EBRT alone, in the RCT of 243 patients. Fistula was reported in 7% (7/106) of patients in the case series of 106 patients.

'Stricture' was reported in 1 patient in a case series of 34 patients. Anastomotic stricture was reported in 3% (3/106) of patients in the case series of 106 patients.

Small bowel obstruction was reported in 8% (8/106) of patients in the case series of 106 patients; all were successfully treated without surgery.

Reoperation was reported in 5% (5/106) of patients treated by a preoperative HDR brachytherapy boost and EBRT compared against 8% (9/109) of patients treated by EBRT alone, in the RCT of 243 patients (p value not reported). Reoperation rates of 4% (13/318), 14% (45/318) and 12% (39/318) were reported for patients treated by preoperative HDR brachytherapy, by short course EBRT or by surgery alone, respectively (p=0.0005), in the non‑randomised comparative study of 954 patients. Surgical intervention for complications was reported in 11% (12/106) of patients in the case series of 106 patients.

In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers listed the following anecdotal adverse events: rectal fistula formation, small bowel stricture, and persisting proctitis. They considered that the following were theoretical adverse events: bladder perforation, mucosal damage causing ulceration and bleeding, stenosis of the rectal lumen or small bowel, and skin changes on the perineum.