Radiotherapy for sinonasal malignancies: evidence, technology and resource-constrained settings

Sinonasal malignancies are rare, biologically heterogeneous tumours arising in a confined anatomical space bounded by the orbit, skull base and brain. This combination of rarity, histological heterogeneity and anatomical constraint influences treatment selection and limits the evidence available to guide it. Radiotherapy is central to management in both the postoperative and definitive settings, and intensity-modulated radiotherapy is now the photon standard, with proton and carbon-ion therapy available in a small number of centres. This review appraises the evidence underlying current practice. Pooled outcome data derived from mixed-histology institutional series are difficult to interpret; definitive radiotherapy cohorts are subject to confounding by treatment allocation; the clinical evidence supporting particle therapy is weaker than the dosimetric evidence; and the evidence base for elective nodal irradiation is inadequate. The review identifies where the evidence supports firm recommendations and where it does not. Because most patients with these tumours are treated in settings without particle therapy, routine magnetic resonance imaging (MRI) or daily volumetric image guidance, it also describes resource-adapted alternatives and their limitations.