Intraoperative Radiotherapy in Rectal Cancer: A Narrative Review
DOI:
https://doi.org/10.34635/rpc.1204Keywords:
Combined Modality Therapy, Intraoperative Care, Margins of Excision, Neoplasm Recurrence, Local, Rectal Neoplasms/radiotherapy, Rectal Neoplasms/surgeryAbstract
Background: Intraoperative radiotherapy (IORT) delivers an elevated radiation dose directly to the tumour bed or high-risk resection areas during rectal cancer surgery, enabling dose escalation beyond the limits of conventional external beam radiotherapy (EBRT). Despite decades of clinical use in specialized centres, its benefit over standard multimodal therapy remains in debate.
Methods: This narrative review synthesises the available evidence on IORT in primary locally advanced rectal cancer (LARC) and locally recurrent rectal cancer (LRRC), drawing on randomized trials, prospective and retrospective series, population-based analyses, national cancer registry data, and current international guidelines.
Results: IORT consistently reduces local recurrence rates in R1 and close-margin resections and achieves pelvic control rates exceeding 85% in selected series when integrated with neoadjuvant chemoradiation and radical surgery. A meta-analysis of seven studies demonstrated a non-significant reduction in local recurrence (14.7% vs 21.4%; OR 0.55), with no demonstrated overall survival benefit. Patient selection, surgical radicality, and institutional experience remain the dominant determinants of outcome.
Conclusions: IORT is an effective dose-escalation adjunct for carefully selected patients with LARC or LRRC at high risk of R1 resection, but its survival impact has not been proven. Standardization of technique, prospective multicentre data collection, and integration with novel systemic agents represent the most critical priorities for future research.
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