3059 - Management of Succinate Dehydrogenase-Mutant Paraganglioma with Stereotactic Radiosurgery

05:00pm - 06:00pm PT

Hall F

Screen: 8

POSTER

Presenter(s)

Paul Harary, BS - Stanford University School of Medicine, San Jose, CA

P. M. Harary¹, Y. Hori¹, A. Zamarud¹, F. Lam¹, D. Reesh¹, S. C. Emrich¹, A. Tayag¹, L. Ustrzynski¹, E. L. Pollom², S. G. Soltys², G. Li¹, D. Park¹, and S. D. Chang¹; ¹Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, ²Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA

Purpose/Objective(s): Mutations in genes encoding the subunits of the succinate dehydrogenase complex (SDH) account for approximately 50% of hereditary paragangliomas (PGLs) and are associated with increased rates of malignancy, multifocality, and recurrence. While the use of stereotactic radiosurgery (SRS) for PGLs has recently expanded, data correlating genetic background with outcomes in this distinct patient population are lacking. We aimed to evaluate the safety and efficacy of SRS in SDH-related PGL across multiple anatomic sites.

Materials/Methods: Patients with confirmed SDH-mutant PGL who underwent SRS at a single institution between January 2009 and January 2024 were retrospectively reviewed. Clinical history, genetic characteristics, SRS treatment parameters, and outcomes were summarized. The primary endpoints were overall survival, local control, and symptom improvement. The secondary endpoint was treatment-related adverse events.

Results: Seven patients (5 female, 2 male) with confirmed SDH pathogenic variants underwent SRS for 10 total PGLs. Median age at initial PGL diagnosis was 32 years (range: 16-56), with a median age of 46 years (range: 18-59) at the time of SRS treatment. Subtotal resection was performed for 3 of 10 lesions prior to treatment with SRS. The glomus jugulare was the most commonly involved anatomic site, followed by the carotid body and glomus vagale. Treatment volume and maximum diameter ranged from 0.3 to 30.8 cm³ and 11 to 50 mm, respectively. The median marginal dose was 21 Gy (range: 16-25). Median follow-up was 34.3 months, with an aggregate local control rate of 100%. Symptoms improved in 80% of cases which were preoperatively symptomatic. A single patient experienced a post-SRS adverse event which required further treatment.

Conclusion: To our knowledge, this represents the first dedicated analysis of SRS treatment outcomes for this hereditary condition. SRS appears to provide durable local control with minimal side effects for SDH-related PGL, suggesting its potential as a treatment strategy. In addition, symptom improvement was reported in the majority of cases.