Radiotherapy of sinonasal cancers: 2025 update

Sinonasal cancers, including tumours of the nasal cavity, ethmoid, maxillary, sphenoid, and frontal sinuses, account for 3 to 5 % of head and neck malignancies. While the majority are carcinomas, other histologic types such as mucosal melanomas, sarcomas, and lymphomas may also occur. These tumours often present with non-specific symptoms and exhibit a heterogeneous prognosis. The Réseau d'expertise français des cancers ORL rares (the French expert network for rare head and neck cancers), accredited by the Institut national du cancer (the French national cancer institute), is responsible for maintaining the national registry and coordinating rare cancer multidisciplinary tumour boards at both regional and national levels. These boards incorporate expert pathological review through Refcorpath (when appropriate) and provide therapeutic recommendations. Due to the distinct characteristics of these tumours, including histologic subtype, grade, risk of nodal involvement, and surgical approach, careful consideration must be given to target volume delineation during locoregional radiotherapy. This article provides an updated overview of the Société française de radiothérapie oncologique (the French society for radiation oncology) recommendations concerning the indications for radiotherapy in sinonasal cancers. It covers key aspects such as treatment planning, techniques, dose and volume specifications, and post-treatment follow-up.