Stereotactic radiosurgery for pituitary metastases: a systematic review and single-arm meta-analysis of local control and survival outcomes

BACKGROUND: Pituitary metastases (PM) are rare intracranial secondary tumors, most often arising from breast and lung primaries. They are clinically significant due to their association with advanced systemic malignancy and potential to cause visual, neurological, and endocrinological morbidity. Conventional therapies such as surgery and fractionated radiotherapy have limited efficacy or high morbidity. Stereotactic radiosurgery (SRS) has emerged as a minimally invasive alternative, but available evidence is limited to small, heterogeneous series. OBJECTIVE: To evaluate the effectiveness and safety of SRS in patients with PM by synthesizing data on tumor control, survival outcomes, progression-free survival (PFS), and treatment-related morbidity. METHODS: A systematic review and meta-analysis were performed according to PRISMA guidelines. PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched through June 2025. Eligible studies included patients with radiologically or histologically confirmed PM treated with SRS. Outcomes of interest were local tumor control, survival, PFS, radiological response, and complications, including hypopituitarism, optic neuropathy, and radiation necrosis. Data were pooled using a random-effects single-arm meta-analysis model. RESULTS: Six retrospective case series comprising 142 patients were included. Pooled local control following SRS was 89% (95% CI 75-96%). Six-month PFS was 97% (95% CI 83-100%). One- and two-year survival rates were 53% (95% CI 32-73%) and 40% (95% CI 15-72%), respectively. Tumor regression occurred in 34% and stable disease in 33%, while only 7% demonstrated progression. Treatment-related morbidity was low: new-onset hypopituitarism (1%), optic neuropathy (2%), and radiation necrosis (1%). CONCLUSION: SRS provides effective and durable local control of pituitary metastases with a favorable safety profile and low rates of treatment-related toxicity. Despite the poor systemic prognosis associated with PM, SRS offers meaningful intracranial disease control and symptom relief, particularly in well-selected patients with stable systemic disease. Larger prospective, standardized studies are needed to further clarify long-term endocrine and neurological outcomes.