Coverage-Driven Obliteration and Neurocognitive Preservation Following LINAC-Based Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy for Intracranial Arteriovenous Malformations: A Single-Institution Case Series

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are established modalities for the treatment of intracranial arteriovenous malformations (AVMs), particularly those situated in eloquent or surgically high-risk locations. Although microsurgical resection remains the preferred approach for low-grade lesions in accessible regions, a subset of Spetzler–Martin grade I to II AVMs may be more appropriately managed with SRS or FSRT when located in eloquent cortex, deeply situated, or when surgical morbidity is a concern following multidisciplinary evaluation. Integrated clinical data evaluating radiological, dosimetric, and neurocognitive outcomes following linear accelerator (LINAC)-based stereotactic treatment remain limited. This retrospective case series included consecutive patients with intracranial AVMs treated with LINAC-based SRS or FSRT between 2018 and 2024. Clinical characteristics, Spetzler–Martin grade, Pollock–Flickinger score, treatment parameters, and dosimetric indices were recorded. Posttreatment imaging follow-up included serial contrast-enhanced magnetic resonance imaging and digital subtraction angiography where clinically indicated. Dosimetric evaluation focused on guideline-relevant parameters including D98%, D2%, and quality of coverage (QRTOG). Neurocognitive function was assessed at baseline, 3 months posttreatment, and last follow-up using a standardized battery. Obliteration probability was evaluated using Kaplan–Meier analysis. Sixteen patients were treated, with 15 completing follow-up. Complete radiological obliteration was achieved in 11 patients (68.8%), with angiographic confirmation in 7. Median time to obliteration was 16 months. One hemorrhagic event occurred during the latency period. Representative angiographic imaging demonstrating pre- and posttreatment nidus obliteration is presented. Obliterated AVMs demonstrated a directional trend toward higher target dose coverage (higher D98% and QRTOG) without higher near-maximum dose. Neurocognitive performance was preserved across assessed domains, with no sustained decline. LINAC-based SRS/FSRT was associated with effective AVM control and preservation of neurocognitive function in this single-institution cohort. Observed dosimetric trends suggest a directional relationship between adequate nidus coverage and obliteration, though these findings are hypothesis-generating and require validation in larger prospective cohorts. Multicenter studies incorporating standardized dosimetric reporting and longitudinal neurocognitive assessment are needed.