Volumetric Analysis of Intracranial Arteriovenous Malformations Contoured for CyberKnife Radiosurgery With 3-Dimensional Rotational Angiography vs Computed Tomography/Magnetic Resonance Imaging

Abstract

Abstract BACKGROUND: Accurate target delineation has significant impact on brain arteriovenous malformation (AVM) obliteration, treatment success, and potential complications of stereotactic radiosurgery. OBJECTIVE: We compare the nidal contouring of AVMs using fused images of contrasted computed tomography (CT) and magnetic resonance imaging (MRI) with matched images of 3-dimensional (3-D) cerebral angiography for CyberKnife radiosurgery (CKRS) treatment planning. METHODS: Between May 2009 and April 2012, 3-D cerebral angiography was integrated into CKRS target planning for 30 consecutive patients. The AVM nidal target volumes were delineated using fused CT and MRI scans vs fused CT, MRI, and 3-D cerebral angiography for each patient. RESULTS: The mean volume of the AVM nidus contoured with the addition of 3-D cerebral angiography to the CT/MRI fusion (9.09 cm3, 95% confidence interval: 5.39 cm3-12.8 cm3) was statistically smaller than the mean volume contoured with CT/MRI fused scans alone (14.1 cm3, 95% confidence interval: 9.16 cm3-19.1 cm3), with a mean volume difference of δ = 5.01 cm3 (P = .001). Diffuse AVM nidus was associated with larger mean volume differences compared with a compact nidus (δ = 6.51 vs 2.11 cm3, P = .02). The mean volume difference was not statistically associated with the patient's sex (male δ = 5.61, female δ = 5.06, P = .84), previous hemorrhage status (yes δ = 5.69, no δ = 5.23, P = .86), or previous embolization status (yes δ = 6.80, no δ = 5.95, P = .11). CONCLUSION: For brain AVMs treated with CKRS, the addition of 3-D cerebral angiography to CT/MRI fusions for diagnostic accuracy results in a statistically significant reduction in contoured nidal volume compared with standard CT/MRI fusion-based contouring.