The Role of Stereotactic Radiosurgery in the Management of Pituitary Metastases: An International Multi-institutional Study

Introduction: Pituitary metastases (PM) accounts for 0.4% of all intracranial metastases and typically presents with visual and endocrinological deficits. Stereotactic radiosurgery (SRS) has shown excellent tumor control and safety profile in the management of intracranial metastases. However, its role and safety in managing metastasis to the pituitary gland is scarcely reported in the literature. This study aims to evaluate SRS outcomes and safety profile in the management of PM in a multicenter international study.

Methods: The authors retrospectively analyzed data from 45 patients with PM treated with SRS across 13 institutions, assessing clinical and radiological outcomes, including survival rates, tumor control, visual and endocrinological outcomes, and post-treatment complications.

Results: Among 45 patients (median tumor volume for PM was 2.3 cc, median margin dose 15 Gy) included in the study, SRS demonstrated local tumor control rate of 94.3% at 12 months, with a median progression-free survival of 85.2 months. The median survival was 28.4 months and overall survival rates of 83.5%, 72.8%, and 61.0% at 6, 12, and 18 months, respectively. Following SRS, 88.9% of patients showed stable or improved visual function with only 11.1% experienced worsening vision. A small percentage of patients experienced complications: 2.2% developed new visual deficits, 4.4% experienced new anterior pituitary hormone deficiency, and 4.4% developed diabetes insipidus post-treatment.

Conclusion : To the best of our knowledge, this is the largest series reported to date on the role of SRS in the management of PM. SRS appears to be a valuable tool in the management of PM, offering excellent local tumor control and survival outcomes with minimal morbidity. These findings support the incorporation of SRS into the multidisciplinary management for treating patients with PM.