Long-term tumor control following gamma-knife radiosurgery of recurrent or residual pituitary adenomas: a population-based cohort study.

Abstract

Pituitary adenomas (PAs) often require adjuvant Gamma Knife radiosurgery (GKRS) due to partial resection or postoperative recurrence. The purpose of this study was to evaluate the long-term efficacy of GKRS for such cases. Population-based, observational cohort study of patients who underwent GKRS for postoperative residual or recurrent PAs between 1999 and 2020. We assessed long-term progression-free survival (PFS), identified predictors of tumor growth, and documented adverse radiation events (AREs). 147 patients were included, with a median follow-up time of 8.1 years. Following GKRS, the 5-year and 10-year PFS was 86% and 68%, respectively, with a median PFS of 18.7 years. Somatotrophic adenomas showed a significantly lower risk of tumor progression in the regression analysis (OR 0.11, p = 0.003). Hypopituitarism was the most common ARE, affecting 32% of patients. GKRS is an effective treatment option for recurrent or residual PAs, offering substantial long-term control. However, the risk for AREs, particularly hypopituitarism, is not negligeable.