Long-Term Outcomes of Jugular Paragangliomas Undergoing Gamma Knife Radiosurgery: A Single Center Experience

BACKGROUND AND OBJECTIVES: Jugular paragangliomas (JPG) pose a surgical challenge because of their vascularity and complex location. Stereotactic radiosurgery (SRS) offers a minimally invasive management for patients with JPG. Our aim was to evaluate outcomes of Gamma Knife radiosurgery (GKRS) for the treatment of JPG over the long term. METHODS: We reviewed our 3.5-decade 17 800 patients' GKRS database. Clinical behavior, treatment parameters, tumor control, complications, and functional status were assessed. RESULTS: Forty patients (median = 56 years [range, 18-88], women = 24) with 40 JPG were included. There were 28 primary and 12 adjuvant GKRS. The median margin dose was 13.5 Gy (range, 12-18) delivered at 50% isodose line. Among patients with adjuvant GKRS, there were more staged-volume SRS (2 sessions) (n = 1 vs n = 3, P = .035) associated with larger tumor volume [3.5 cc (1.1-26.7) vs 10.2 cc (3.3-45.9), ( P = .038) and increased V12Gy ( P = .031). Better House-Brackmann grade ( P = .008) and Gardner-Robertson hearing class ( P < .001) before GKRS correlated with better facial nerve function and unchanged cochlear nerve function after treatment, respectively. During an overall median follow-up of 69.7 months (range, 6.0-339.3 months), symptom control and preserved functionality were achieved in 39 patients (97.5%). Tumor control was obtained in 38 patients (95%) (regression = 23, stable = 15) after SRS. The 5-, 10-, and 15-year progression-free survival rates were all 100% after primary GKRS and 91.7%, 83.3%, and 83.3% for adjuvant GKRS ( P = .101). Larger (≥10 cc) tumor volumes (HR: 1.35 [95% CI: 1.11-1.70], P = .013) and mFisch Di2 (HR: 1.40 [95% CI: 1.18-1.64], P = .016) were associated with worse progression-free survival. One patient required a second GKRS after asymptomatic progression with no further growth. One patient with 2 failed surgical resections died 8 months after adjuvant GKRS related to tumor progression and hydrocephalus. CONCLUSION: As a minimally invasive management, GKRS proved to be a safe and effective treatment of JPG. GKRS should be considered both as an optimal primary management and as an early adjuvant strategy for residual or recurrent tumors after initial resection.