Radiation Exposure During Diagnostic and Therapeutic Angiography of Carotid-cavernous Fistula: A Retrospective Single Center Observational Study

PURPOSE: The aim of this study was to determine local diagnostic reference levels (DRLs) during endovascular diagnostics and therapy of carotid-cavernous fistulas (CCF). METHODS: In a retrospective study design, DRLs, achievable dose (AD) and mean values were assessed for all patients with CCF undergoing diagnostic angiography (I) or embolization (II). All procedures were performed with the flat-panel angiography system Allura Xper (Philips Healthcare). Interventional procedures were differentiated according to the type of CCF and the type of procedure. RESULTS: In total, 86 neurointerventional procedures of 48 patients with CCF were executed between February 2010 and July 2021. The following DRLs, AD and mean values could be determined: (I) DRL 215 Gy ∙ cm(2), AD 169 Gy ∙ cm(2), mean 165 Gy ∙ cm(2); (II) DRL 350 Gy ∙ cm(2), AD 226 Gy ∙ cm(2), mean 266 Gy ∙ cm(2). Dose levels of embolization were significantly higher compared to diagnostic angiography (p < 0.001). No significant dose difference was observed with respect to the type of fistula or the embolization method. CONCLUSION: This article reports on diagnostic and therapeutic DRLs in the management of CCF that could serve as a benchmark for the national radiation protection authorities. Differentiation by fistula type or embolization method does not seem to be useful.