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

Abstract

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. 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. 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. 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.