KEY POINTS
- An international multidisciplinary ESTRO panel conducted a systematic review addressing 14 clinical questionson patient selection, planning and delivery of reirradiation for locally recurrent rectal cancer; the recommendations were endorsed by ASTRO.
- For neoadjuvant reirradiation, recommended regimens include 40.8 Gy in 1.2 Gy twice-daily fractions, 30–39 Gy in 1.5 Gy twice-daily fractions, or 30 Gy in 1.8–2 Gy daily fractions, with intraoperative radiotherapy considered where appropriate.
- Definitive reirradiation may use the same 30–40 Gy schedules for prolonged local and symptom control. For patients with poor performance status and expected survival below six months, 8 Gy in one fraction or 20 Gy in five fractions are reasonable palliative options.
- Previous radiotherapy should be reconstructed where possible, with cumulative normal-tissue dose evaluated using equieffective dose. Neoadjuvant and definitive treatments should use intensity-modulated or volumetric-modulated arc therapy, while daily volumetric imaging is recommended for stereotactic treatment and strongly considered for other curative-intent regimens.
- Stereotactic body radiotherapy may be considered for one to three small, discrete recurrences without gastrointestinal or bladder invasion. Proton and carbon-ion therapy may be considered at experienced centres, but comparative clinical evidence remains limited.
CLINICAL TAKEAWAY
These recommendations provide a practical framework for integrating reirradiation into neoadjuvant, definitive and palliative management of locally recurrent rectal cancer. They support specialist multidisciplinary selection, cumulative dose assessment and precision delivery, but most recommendations remain based on low-quality evidence or expert consensus rather than comparative trials.