2638 - Stereotactic Radiosurgery for Myxomatous Oncotic Cerebral Aneurysms: A Case Series
Presenter(s)
N. G. Nelson1, A. C. Wang2, V. Szeder3, and T. B. Kaprealian1; 1Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, 2Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, 3Division of Interventional Neuroradiology, University of California, Los Angeles, Los Angeles, CA
Purpose/Objective(s): Oncotic aneurysms are a rare metastatic phenomenon observed in a few cancer types, including atrial myxoma. Given their neoplastic growth potential and rupture risk, interventions to control myxomatous oncotic cerebral aneurysms (MOCA) may be indicated. Depending on MOCA morphology, location, and patient comorbidities, vascular or surgical techniques can be high-risk. If MOCA control requires sacrifice of the host vessel, this threatens any eloquent cortex downstream of the lesion. Stereotactic radiosurgery (SRS) may offer a noninvasive alternative for providing MOCA control. We hypothesized that SRS is an appropriate modality for controlling growth of oncotic cerebral aneurysms arising from atrial myxomas.
Materials/Methods: We performed a single-institution retrospective case series that included all patients with a history of atrial myxoma who received SRS to one or more oncotic aneurysms. We recorded the measurements of each documented MOCA at the time of diagnosis, pre-SRS, 6 months post-SRS, 12 months post-SRS, and at the time of most recent imaging. Electronic medical records were also reviewed for details about their presentation, treatment, and MOCA-related clinical outcomes.
Results: Patients who received SRS for MOCA were identified (n = 4), with a total of 18 targets treated on 9 SRS treatment dates spanning 2016–2024; all were treated to 14 Gy / 1 fx. One patient initially presented with MOCA hemorrhage, and all patients had evidence of prior ischemic/embolic events at the time of MOCA diagnosis. Factors that influenced recommendation for SRS included: MOCA progression or multiplicity; eloquent location; aneurysm morphology; poor patient surgical candidacy; patient stroke risk; and patient preference for minimally invasive intervention. Outcomes for MOCA status were obtained for the 12 targets with adequate time (>1 year) since SRS: obliteration (3), marked decrease with obliteration of distal branches (1), marked decrease to stable (1), decrease to stable (4), stable (2), mild increase to stable (1). Treatments were well-tolerated without any acute complications; SRS-associated adverse effects included one episode of steroid-responsive radionecrosis and possible contribution to preexisting chronic neurological conditions in two patients. No hemorrhages were observed for any treated MOCA.
Conclusion: SRS may be a reasonable alternative for MOCA control in select patients with neurosurgical contraindications. Further research is warranted to broaden the management strategies for this rare but recognized condition.