Contact X-ray brachytherapy in rectal cancer: A systematic review and meta-analysis

Abstract

Rectal cancer is a highly prevalent disease. Evidence presented in the 2025 phase-III OPERA randomised trial suggests that Contact X-ray Brachytherapy (CXB), with external beam chemoradiotherapy, is a viable organ-preserving alternative to radical surgery. We conducted a systematic review and meta-analysis to assess the clinical effectiveness of CXB in the treatment of rectal cancer. This systematic review was prospectively registered (CRD42021284969) and reported following PRISMA guidelines. Multiple electronic databases were interrogated using the search terms "Rectal cancer", "Contact Brachytherapy", and synonym terms. Clinical complete response (cCR) was the primary outcome. Proportional meta-analyses were conducted and presented as forest plots with summary proportions and 95 % confidence intervals. The literature search identified 973 studies, of which 52 studies encompassing 5447 patients met the inclusion and exclusion criteria and were included in the meta-analysis. Pooled estimates of outcomes were as follows: cCR rate = 82 % (95 % CI 76-88 %), Local Regrowth rate = 20 % (95 % CI 15-25 %), regional metastasis rate = 3 % (95 % CI 2-4 %), salvage surgery rate = 14 % (95 % CI 11-18 %), long-term disease control post-salvage surgery rate = 88 % (95 % CI 78-96 %) and organ preservation = 81 % (95 % CI 74-88 %). CXB in the appropriately selected patient population can achieve long-term disease control and organ preservation whilst avoiding major surgery. Salvage surgery remains a viable option for patients who experience disease regrowth with excellent long-term disease control. Clinicians should discuss CXB with rectal cancer patients, presenting it as a viable and safe alternative to radical surgery. This is particularly pertinent for patients who are stoma-averse or older patients in frail health.

Keywords: Contact X-ray brachytherapy; Papillon; Rectal cancer.