2025 Proffered Presentations
S117: STEREOTACTIC RADIOSURGERY IN THE MANAGEMENT OF PITUITARY METASTASES: AN INTERNATIONAL MULTICENTER STUDY
Hussam Abou-Al-Shaar, MD1; Ibrahem Albalkhi2; Rimsha K Shariff, MD1; Arka N Mallela, MD, MS1; Pouneh K Fazeli, MD1; Salem M Tos, MD3; Georgios Mantziaris, MD3; Ying Meng, MD4; Kenneth Bernstein, MD, MS4; Tehila Kaisman-Elbaz, MD, PhD5; Hanan Abofani, MD5; Yen-Yu Lin, MD6; Cheng-chia Lee, MD6; Manjul Tripathi, MCh7; Rituraj Upadhyay, MD8; Joshua D Palmer, MD8; Ahmed M Nabeel, MD, PhD9; Wael A Reda, MD, PhD9; Sameh R Tawadros, MD, PhD9; Khaled Abdelkarim, MD, PhD9; Amr M El-Shehaby, MD, PhD9; Reem M Emad, MD, PhD9; Selcuk Peker, MD10; Yavuz Samanci, MD10; Rodney E Wegner, MD11; Matthew J Shepard, MD11; Roman Liscak, MD12; Gabriela Simonova, MD12; Timoteo Almeida13; Carolina Benjamin, MD13; Douglas Kondziolka, MD, MSc4; Jason P Sheehan, MD, PhD3; Ajay Niranjan, MD, MBA1; L. Dade Lunsford, MD1; 1University of Pittsburgh Medical Center; 2Alfaisal University; 3University of Virginia; 4NYU Langone; 5Sheba Medical Center; 6Taipei Veterans General Hospital; 7PGIMER; 8Ohio State University; 9Nasser Institute Hospital; 10Koc University School of Medicine; 11Allegheny Health Network; 12Na Homolce Hospital; 13University of Miami
Objectives: Metastases into the pituitary gland, although rare, have been increasingly detected due to advances in imaging and systemic therapies. Patients typically present with diabetes insipidus and other hormonal derangements as well as visual and neurological symptoms. Stereotactic radiosurgery (SRS) has shown promising results in the management of this condition. However, the data on its safety and efficacy remains scarce in the literature. This study aims to evaluate the role, safety, and outcomes of SRS in the management of pituitary metastases.
Methods: The authors conducted a retrospective review of records from centers participating in the International Radiosurgery Research Foundation involving patients with pitautary metastases treated with SRS. The primary outcomes analyzed included survival rates, tumor control, pituitary hormone function outcomes, visual function, incidence of adverse radiation effects (AREs), and the need for further therapeutic interventions.
Results: A total of 45 patients with a median age of 61.0 years (IQR 52-70 years) underwent SRS for pituitary metastases. The most common primary origins of the metastases were lung (37.8%) and breast (26.7%) cancers. Diabetes insipidus and pitautary hormone deficiencies were present in 22.2% and 41.5% of patients, respectively. Prior to SRS of the pituitary metastasis, 20% had surgical resection and 4.4% had another form of radiation therapy . Optic nerve compression with visual problems was observed in 20% of patients. The median tumor volume was 2.2 cc (range 0.1-22.6 cc). The median marginal and maximum doses were 15 Gy (range 6-32 Gy) and 26.7 Gy (range 11.9-64.0 Gy), respectively. Post-SRS complications included new pituitary hormone deficiency (thyroid hormone deficiency and adrenal insufficiency) in two patients (4.4%) and new-onset diabetes insipidus in one patient (2.2%). Additionally, one patient developed a new-onset optic neuritis, and another had a worsening of an existing visual acuity deficit. However, out of the nine patients with visual deficits before SRS, visual function improved in 44.4%. The pituitary metastasis progression rates at 6-, 12-, and 18-months were 5.9%, 10.2%, and 15.8%, respectively (Figure 1). The overall survival rates at 6-, 12-, and 18-months were 83.4%, 72.8%, and 61.0%, respectively (Figure 2). The median progression-free survival was 85.2 months, and the median overall survival post-SRS was 28.4 months, with 1 patient requiring further SRS treatment. The 2-year tumor control rate was 84.2%. The median follow-up period was 14.7 months (range 1.0-101.4 months).
Conclusion: SRS is an important minimally invasive modality in the multidisciplinary management of pituitary metastases, offering optimal local tumor control and survival outcomes with minimal morbidity. Our findings support the incorporation of SRS into the multidisciplinary approach for treating patients with this rare entity.
Figure 1: Progression-free survival post-SRS.
Figure 2: Overall survival post-SRS.
