Long-Term Follow-Up of Post Radiation Complete Sinus Opacification in Sinonasal Cancer Patients

ObjectiveTreatment of sinonasal malignancies most often requires primary or postoperative radiation treatment. Post radiation sinonasal morbidity has been previously described; however, none addressed post-radiation sinus obstruction. Our objective was to investigate the long-term outcomes of post radiation complete isolated sinus opacification (CISO).MethodsA retrospective analysis of sinonasal cancer patients treated with radiation therapy during the years 2002 to 2022. Clinical, imaging and treatment data were collected from patients' medical records. Only patients with at least 12 months of follow-up and available imaging for review were included.ResultsOut of 109 patients, 37 patients were identified to meet the inclusion criteria. Mean follow-up was 58 months. 35% of patients were diagnosed with persistent post radiation CISO with a mean onset of 4 months. All these patients remained asymptomatic, and their imaging remained stable during follow-up with none developing an expanding mucocele. Ethmoid sinus tumor involvement was found to be more prevalent in the CISO group (62% vs. 25%, p-value = 0.048) as well as chemotherapy/immunotherapy (54% vs. 38%, p-value = 0.046). Multivariant analysis revealed that ethmoid sinus involvement (OR = 9.516, p-value = 0.047) and adjuvant therapy, either chemotherapy/immunotherapy (OR = 10.75, p-value = 0.036) were found to be a predictive factor for complete opacification.ConclusionOur study revealed that a substantial number of post-radiation patients develop a stable and persistent CISO, often in the frontal and sphenoid sinuses. These patients remained asymptomatic, and none required surgical intervention during nearly 5 years of follow-up.Level of Evidence4 Laryngoscope, 2024 Some post-radiotherapy patients experience complete obliteration of the sphenoid or frontal sinuses, supposedly posing a risk for sinusitis or mucocele development. The objective is to comprehensively assess the natural history and outcomes of radiation-induced complete isolated sinus opacification. Our study revealed that a substantial number of post-radiation patients develop complete isolated sinus opacification, often in the frontal and sphenoid sinuses. These patients remained asymptomatic, and none required surgical intervention during nearly 5 years of follow-up. image