RARE-12. VASCULOPATHY IN PEDIATRIC CRANIOPHARYNGIOMA PATIENTS TREATED WITH SURGERY AND RADIOTHERAPY

PURPOSE: As much as 40% of pediatric brain tumor patients will experience varied levels of Vasculopathy (VS), however few predictive factors have been described. Here we describe the type and timing of VS and explore the relationship between treatment modality and the timing, location, and distribution of VS. METHODS: 94 pediatric Craniopharyngioma patients underwent surgery and proton radiotherapy. Pre- and post-treatment imaging, cumulative physical and biological proton dose maps, clinical characteristics, and measures of dyslipidemia were evaluated. MR and MRAs were evaluated for pre- and post-radiotherapy VS (type, workup, location, and severity). VS events were segmented and described according to their normal brain region, and vascular territory. RESULTS: 47 patients were found to have 154 confirmed VS of varying severity with a median time to event of 3.41 years 95% CI 3.08–3.88. 22% (N=21) of patients had ≥1 pre-existing instances of VS and 26.6% (N=25) had a dyslipidemia at diagnosis. Forty-six (48.9%) patients had evidence of VS post-RT with 9.5% (N=9) being clinically significant. Aspirin was recommended in 10.6% (N=10) patients. Only 4 (4.2%) patients required revascularization. Clinical characteristics were not predictive of VS. An increased frequency of VS were observed along the operative corridor and high-dose radiotherapy field. CONCLUSIONS: VS often precedes radiotherapy necessitating appropriate baseline imaging. Surgery type and extent are interrelated to the risk for radiotherapy-induced VS. While the spatial radiotherapy dose distribution approximated most vascular injury events, it was not all-inclusive. Spatial modeling of biological and physical dose may offer insights into therapy related vascular injury.