The long-term outcome of CyberKnife therapy for head and neck paraganglioma: Management suggestion from a single center experience

Abstract To analyze the long-term follow-up data of CyberKnife treatment (CKT) for head and neck paragangliomas (HNPGs). Patients who received CKT to HNPGs from 2010 to 2019 were retrospectively reviewed. A total of 34 HNPGs from 29 patients were identified. The mean age was 50 (± 16) years old, and 15 patients (52%) were female. Previous operation was done in 15 patients (55%). Four cases (14%) were functional in hormone production. According to Fisch classification, one case (3%) was B, 12 (42%) were C, 14 (48%) were D, and two cases (7%) were out of classification. The median prescribed dose covered 95% of the planning target volume was 2500 (IQR 2100–2600) cGy and the median target volume was 10 (IQR 5.8–21.3) cm3. The local control rate was 97%. The median progression-free survival was 66 (IQR 28–95) months and 96% were free of tumor progression at eight years. During the follow-up, one case (3%) resulted in permanent facial nerve palsy (House-Brackmann grade II), and another case (3%) resulted in asymptomatic cerebellar radiation necrosis. Univariate and multivariate analysis showed no previous surgical history (OR 8.58, 95% CI 1.2–59.7, p = 0.03) was a positive predictor of symptom improvement. We devised a treatment flow-chart based on our finding. CKT for HNPGs was an effective treatment with little side effect over the long term and may have a role in the first-line therapy especially for symptomatic nonfunctional HNPGs for better symptom control.