Long-Term Outcomes After Gamma Knife Radiosurgery for Craniopharyngioma: A Single-Center Retrospective Study

BACKGROUND AND OBJECTIVES: Craniopharyngiomas are benign sellar and suprasellar tumors associated with substantial long-term morbidity and risk of recurrence. Gamma knife radiosurgery (GKRS) is commonly used for residual or recurrent disease, but contemporary long-term outcome data remain limited. This study evaluated long-term outcomes after GKRS and explored volume-associated and dose-associated predictors of radiographic failure. METHODS: A retrospective single-center cohort study of 72 craniopharyngiomas treated with GKRS. The primary end point was clinically relevant disease control failure, defined as radiographic progression (solid and/or cystic) and/or any craniopharyngioma-directed intervention after GKRS. Secondary end points included radiographic progression alone and overall survival. RESULTS: The median age was 32.5 years, the median margin dose was 11.5 Gy, and the median follow-up was 108.2 months. Clinically relevant disease control failure occurred in 25/72 (34.7%), comprising 5/72 (6.9%) radiographic progressions and 20/72 (27.8%) symptom-driven interventions. Radiographic progression occurred at a median of 15.0 months and was managed with salvage resection in all cases. Radiographic failure was lower with gross tumor volume (GTV) <2.0 cm3 (1/44, 2.3%) than GTV ≥2.0 cm3 (4/26, 15.4%); within GTV ≥2.0 cm3, no failures occurred with margin dose ≥12.5 Gy (n = 7) vs 4 failures with <12.5 Gy (n = 19). Overall survival was 93.6% at 5 years and 88.9% at 10 years. CONCLUSION: GKRS achieved durable radiographic control, while symptom-driven interventions were common and should be incorporated into clinically relevant disease control endpoints. Larger volume was associated with worse radiographic control; the ≥12.5 Gy signal in higher-volume tumors warrants validation.