Preoperative high dose rate brachytherapy for rectal cancer

4 Efficacy

This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.

4.1 A randomised controlled trial (RCT) of 221 patients treated by a preoperative high dose rate (HDR) brachytherapy boost and external beam radiotherapy (EBRT) or by EBRT alone, with concomitant chemotherapy, reported that 66% of 2‑year survivors and 65% of 5‑year survivors had a stoma, with no difference between the groups (p=1.00). A non‑randomised comparative study of 230 patients treated by preoperative brachytherapy or by surgery alone reported that the sphincter was preserved in 72% (69/96) of patients treated by preoperative brachytherapy compared against 42% (48/115) of patients treated by surgery alone (p<0.0001).

4.2 An RCT of 243 patients treated by a preoperative HDR brachytherapy boost and EBRT or by EBRT alone, with concomitant chemotherapy, reported R0 resection (complete resection with no microscopic residual tumour) in 99% (87/90) and 90% (83/92) of patients, respectively (p=0.03). A non‑randomised comparative study of 954 patients treated by preoperative HDR brachytherapy, by short course EBRT or by surgery alone reported R0 resection in 97% (307/318), 83% (265/318) and 74% (236/318) of patients, respectively (p=0.03 for preoperative brachytherapy compared against short course EBRT).

4.3 The RCT of 243 patients treated by a preoperative HDR brachytherapy boost and EBRT or by EBRT alone, with concomitant chemotherapy, reported a 'major response' in 44% (35/80) and 28% (23/82) of patients, respectively (p=0.04). The difference in response rate was greater for tumours less than 3.7 cm in diameter. A case series of 285 patients reported a complete pathological response rate of 27% after preoperative HDR brachytherapy and surgery.

4.4 The non‑randomised comparative study of 230 patients reported that 8% (8/96) of patients treated by preoperative brachytherapy developed local recurrence, compared against 21% (24/115) of patients treated by surgery alone (p=0.005). The case series of 285 patients reported an actuarial local recurrence rate of 5% at 5 years after preoperative HDR brachytherapy and surgery.

4.5 The RCT of 221 patients treated by a preoperative HDR brachytherapy boost and EBRT or by EBRT alone, with concomitant chemotherapy, reported progression‑free 5‑year survival of 52% and 64%, respectively (p=0.32). The non‑randomised comparative study of 230 patients reported disease‑free survival of 72% (69/96) for patients treated by preoperative brachytherapy (median follow‑up 49.5 months) compared against 65% (75/115) for patients treated by surgery alone (median follow‑up 47.5 months; p value not stated). The case series of 285 patients reported 5‑year disease‑free survival of 65% after preoperative HDR brachytherapy and surgery.

4.6 The RCT of 221 patients treated by a preoperative HDR brachytherapy boost and EBRT or by EBRT alone, with concomitant chemotherapy, reported overall 5‑year survival of 64% and 71%, respectively (p=0.34). The non‑randomised comparative study of 230 patients reported actuarial probability of 5‑year survival of 62% for patients treated by preoperative brachytherapy and 65% for patients treated by surgery alone. The case series of 285 patients reported 5‑year overall survival of 68% after preoperative HDR brachytherapy and surgery.

4.7 The specialist advisers listed the following key efficacy outcomes: sphincter preservation rate compared with conventional therapy; histopathological outcomes of surgery; R0 resection rates; quality of life; bowel, urinary and sexual function; local recurrence rates; disease‑free survival and overall survival.