Rectal cancer radiotherapy: 2025 update

We present the updated recommendations of the Société française de radiothérapie oncologique (SFRO, the French society for oncological radiotherapy) for rectal cancer radiotherapy. The standard treatment for locally advanced rectal cancer consists in chemoradiotherapy followed by radical surgery with total mesorectal resection and adjuvant chemotherapy according to nodal status. Although this strategy efficiently reduced local recurrences rates below 5 % in expert centres, functional sequelae could not be avoided resulting in 20 to 30 % morbidity rates. The early introduction of neoadjuvant chemotherapy followed by chemoradiation has proven to be beneficial in recent trials, in terms of recurrence-free and metastasis-free survivals becoming the new standard treatment strategy. Complete pathological responses were obtained in 15 % of tumours treated by chemoradiotherapy, even reaching up to 30 % of tumours when neoadjuvant chemotherapy is associated to chemoradiotherapy. These good results question the relevance of systematic radical surgery in good responders. Personalized therapeutic strategies are now possible by improved imaging modalities with circumferential margin assessed by magnetic resonance imaging, by intensity-modulated radiotherapy and by refining surgical techniques, and contribute to morbidity reduction. Keeping the same objectives, ongoing trials are now evaluating therapeutic de-escalation strategies, in particular rectal preservation for good responders after neoadjuvant treatment or radiotherapy omission in selected cases.