Biomaterial Database

Adjuvant versus on-progression Gamma Knife radiosurgery for residual nonfunctioning pituitary adenomas: a matched-cohort analysis. 2022

Georgios Mantziaris, and Stylianos Pikis, and Tomas Chytka, and Roman Liščák, and Kimball Sheehan, and Darrah Sheehan, and Selcuk Peker, and Yavuz Samanci, and Shray K Bindal, and Ajay Niranjan, and L Dade Lunsford, and Rupinder Kaur, and Renu Madan, and Manjul Tripathi, and Dhiraj J Pangal, and Ben A Strickland, and Gabriel Zada, and Anne-Marie Langlois, and David Mathieu, and Ronald E Warnick, and Samir Patel, and Zayda Minier, and Herwin Speckter, and Zhiyuan Xu, and Rithika Kormath Anand, and Jason P Sheehan

1Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia.

OBJECTIVE Radiological progression occurs in 50%-60% of residual nonfunctioning pituitary adenomas (NFPAs). Stereotactic radiosurgery (SRS) is a safe and effective management option for residual NFPAs, but there is no consensus on its optimal timing. This study aims to define the optimal timing of SRS for residual NFPAs. METHODS This retrospective, multicenter study involved 375 patients with residual NFPAs managed with SRS. The patients were divided into adjuvant (ADJ; treated for stable residual NFPA within 6 months of resection) and progression (PRG) cohorts (treated for residual NFPA progression). Factors associated with tumor progression and clinical deterioration were analyzed. RESULTS Following propensity-score matching, each cohort consisted of 130 patients. At last follow-up, tumor control was achieved in 93.1% of patients in the ADJ cohort and in 96.2% of patients in the PRG cohort (HR 1.6, 95% CI 0.55-4.9, p = 0.37). Hypopituitarism was associated with a maximum point dose of > 8 Gy to the pituitary stalk (HR 4.5, 95% CI 1.6-12.6, p = 0.004). No statistically significant difference was noted in crude new-onset hypopituitarism rates (risk difference [RD] = -0.8%, p > 0.99) or visual deficits (RD = -2.3%, p = 0.21) between the two cohorts at the last follow-up. The median time from resection to new hypopituitarism was longer in the PRG cohort (58.9 vs 29.7 months, p = 0.01). CONCLUSIONS SRS at residual NFPA progression does not appear to alter the probability of tumor control or hormonal/visual deficits compared with adjuvant SRS. Deferral of radiosurgical management to the time of radiological progression could significantly prolong the time to radiosurgically induced pituitary dysfunction. A lower maximum point dose (< 8 Gy) to the pituitary stalk portended a more favorable chance of preserving pituitary function after SRS.