Radiological, Dosimetric, and Neurocognitive Outcomes Following LINAC-Based Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy for Intracranial Arteriovenous Malformations: A Retrospective Institutional Study

Background: Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are established treatment options for intracranial arteriovenous malformations (AVMs), particularly for lesions located in eloquent or surgically high-risk regions. Obliteration occurs after a latency period during which haemorrhage risk persists, and concerns regarding neurocognitive effects remain relevant. Data integrating radiological, dosimetric, and neurocognitive outcomes following LINAC-based radiosurgery are limited. Methods: This retrospective observational study included 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 (QRTOG, HI-RTOG, CI-Lomax, and DVH metrics) were recorded. Neurocognitive function was assessed longitudinally using a standardized battery at baseline, three months post-treatment, and last follow-up. Outcomes were analysed descriptively using paired non-parametric comparisons. Results: Sixteen AVM patients were treated, with fifteen completing follow-ups. Complete radiological obliteration was achieved in 11 patients (68.8%). Angiographic confirmation was available in 7 patients, all demonstrating complete nidus obliteration. Median time to obliteration was 16 months. One patient experienced haemorrhage during the latency period. Dosimetric analysis demonstrated reduced target coverage in this patient compared with the remainder of the cohort. Neurocognitive assessment demonstrated preserved or improved performance across most domains, with no sustained decline observed. Conclusions: LINAC-based SRS/FSRT achieved effective AVM control with a low observed rate of post-treatment haemorrhage. Longitudinal neurocognitive outcomes were largely preserved. All findings should be interpreted in the context of a small retrospective cohort and are hypothesis-generating.