Radiation-induced rhinosinusitis in patients with nasopharyngeal carcinoma

Radiotherapy (RT) is the primary treatment for nasopharyngeal carcinoma (NPC), while its impact on sinonasal mucosa is unclear. We aimed to investigate the progression of sinus mucosal inflammation pre- and post-RT in NPC patients and aid in the prevention and treatment of radiation-induced rhinosinusitis (RiRS).

This study was based on a prospective cohort with 1410 NPC patients. RiRS was evaluated by the Lund-Mackay score (LMS). A prediction model incorporating clinicopathological factors, radiomics features, and dosimetric parameters was developed using least absolute shrinkage regression and validated internally and externally using the area under the receiver operating characteristic curve, calibration tests, and decision curve analysis. LMS trajectories were analyzed using latent-class growth analysis.

1017 patients with a median follow-up of 106.5 months were enrolled. Before RT, 7.5 % of patients (n = 76) had rhinosinusitis, which has increased to 47.2 % after RT. The V30Gy of the sinuses (relative sinus volume receiving doses > 30 Gy), pre-RT LMS abnormalities, and tumor invasion of sphenoidal base independently influenced RiRS. The prediction model based on these three factors exhibited good discrimination and calibration. Three distinct trajectories of RiRS were identified: increasing LMS, decreasing LMS with a high starting score, and decreasing LMS with a low starting score. V70Gy showed significant association with the LMS trajectories.

RiRS is a common complication in NPC patients, influenced by radiation dose in the sinuses, baseline sinus mucosa status, and tumor invasion. Patients with large sinus volumes receiving high radiation doses are more likely to develop RiRS.