Abstract No. 454 Non-contrast cone-beam CT as a surrogate marker for adequacy of treatment in uterine artery embolization

To describe the utility of routine post-procedure non-contrast cone-beam CT (ncCBCT) as a sensitive test for the detection of incomplete treatment during uterine artery embolization (UAE). From 6/2013-6/2018, 427 patients (age, 45±5 years) underwent 430 consecutive UAEs with post-embolization ncCBCT. If ncCBCT showed an area of the uterus lacking contrast retention, aortography was performed to search for collateral supply. Procedures were characterized as suspected complete bilateral UAEs or suspected incomplete UAEs, such as in cases of a unilateral uterine artery or diminutive uterine arteries. Rates of inadequate contrast retention on ncCBCT and discovered collateral artery supply were calculated. In ten consecutive cases in which both ncCBCT and aortogram were performed, dose area product (DAP) radiation exposure from ncCBCT and aortogram were compared using a two-sided paired-samples t-test. Of the 411 suspected complete bilateral UAEs, ncCBCT showed an area of the uterus lacking contrast retention in 38 (9.2%) cases. Of the 19 suspected incomplete UAEs, ncCBCT demonstrated incomplete treatment in six (31.6%) patients. Aortography was performed in 40 of the 44 cases of incomplete treatment on ncCBCT, and collateral supply was found in 28 (70.0%) cases. In 22 of these cases (5.2% of the 427 patients studied), ncCBCT led to the discovery of significant collateral supply requiring further embolization. DAP radiation exposure from ncCBCT was not greater than from aortogram (p=0.006663). Post-UAE ncCBCT can be used to select a subset of patients with a higher likelihood of collateral supply that may benefit from post-embolization aortography.