Long-term clinical outcomes and recurrence factors in intracranial germinoma

PURPOSE: Intracranial germinomas have a favorable prognosis, but recurrence is not uncommon. Risk factors for recurrence and optimal long-term follow-up strategies remain undefined. This study assessed long-term outcomes and recurrence-related factors. METHODS: Patients with intracranial germinomas treated at a single institution between 1984 and 2024 were retrospectively reviewed. Long-term overall survival (OS) and progression-free survival (PFS) were evaluated. Recurrence factors were analyzed by comparing the recurrence and non-recurrence groups. For patients receiving whole ventricular irradiation (WVI) or whole-brain radiation therapy (WBRT), irradiation plans were re-evaluated to determine whether the entire ventricular system was covered. RESULTS: Forty-three patients were included (median follow-up, 11.0 years). The 10-/15-year OS and PFS rates were 97.4%/81.8% and 86.1%/81.3%, respectively. Eight patients (18.6%) experienced disease recurrence. Univariate analysis showed that atypical tumor location and non-complete response after initial treatment were associated to higher recurrence risk, whereas radiation therapy (RT) including the entire ventricular system was associated with lower risk. Multivariate analysis showed that RT including the entire ventricular system reduced recurrence risk (hazard ratio 0.060; 95% CI 0.012-0.312; p < 0.001). Among the eight recurrence cases, three involved spinal recurrence after prolonged remission at 8.4, 17.5, and 18.1 years, respectively. CONCLUSIONS: RT including the entire ventricular system can prolong PFS. Among patients who underwent whole-ventricular RT using opposing portal radiation, some had insufficient radiation field coverage. Even after long-term remission, clinicians should review the initial RT field, and cases with insufficient ventricular irradiation should be monitored closely for recurrence risk.