Gamma Knife treatment of papillary craniopharyngioma: a single-center study of tumor control and predictors of progression

Background Papillary craniopharyngioma (PCP) is a rare sellar tumor distinct from adamantinomatous type. Although Gamma Knife radiosurgery (GKRS) treats craniopharyngiomas effectively, dedicated PCP-only GKRS outcome series are scarce. We evaluated tumor control and prognostic factors following GKRS for PCP. Methods We retrospectively analyzed 34 patients with histologically confirmed PCP who underwent GKRS at Beijing Tiantan Hospital (2002–2025) for residual/recurrent disease after surgery. Primary endpoint was progression-free survival (PFS). Kaplan-Meier and Cox regression analyses identified prognostic factors. Results Thirty-four patients (18 males, mean age 41.7 ± 13.6 years) received GKRS with median marginal dose 12 Gy to median tumor volume 1.10 cm³. With a median clinical follow-up of 54.10 months, the 1-, 3-, and 5-year PFS rates were 91.18%, 82.35%, and 73.53%, respectively. Overall survival was 94.12%. Disease control rate was 70.59%. Exploratory analysis with limited statistical power (10 events, EPV = 3.3) suggested potential associations between tumor volume > 1.1 cm³ (HR = 3.86, P = 0.061) and preoperative hypogonadism (HR = 3.94, P = 0.058) with progression, though these findings require validation in larger cohorts. Visual deterioration was significantly higher in progression group (80.0% vs. 16.7%, P = 0.002). Most patients (61.8%) maintained good quality of life. Conclusion GKRS provides effective long-term tumor control for postoperative PCP patients with acceptable safety profile. Exploratory hypothesis-generating analysis suggested potential associations between tumor volume and preoperative gonadal function status with progression, though these findings require validation in adequately powered studies. These findings support GKRS as a valuable treatment option in the multimodal management of PCP, particularly for patients with residual or recurrent disease after surgery.