Lu YT, Lu YC, Cheng HC, et al. - Given chronic rhinosinusitis (CRS) represents a common post-radiotherapy (RT) side effect among patients suffering from nasopharyngeal cancer, researchers undertook this retrospective cohort analysis to examine the link, if any, between CRS and RT in patients with head and neck cancer. Cases newly diagnosed with head and neck cancer were identified from the 2005 Longitudinal Health Insurance Database. Participants were grouped based on the treatment regimens used: RT alone (RT-alone), RT combined with other treatments (any-RT), and treatments without RT (no-RT). Subgroups were defined according to different treatment policies, and the 5-year incidence of CRS was estimated to be 12%, 9.3%, and 4.5% in the RT-alone group, any-RT group, and no-RT group, respectively. An increased risk of CRS was observed in patients in the RT-alone and any-RT groups vs those in the no-RT group. This work represents the first nationwide population-based cohort analysis to assess the risk of posttreatment CRS among patients having head and neck cancer. RT was identified as a major risk factor for CRS and therefore clinicians are advised to take into account this potential risk in patients with head and neck cancer post-RT.