Safety Margins of Hepatocellular Carcinoma Demonstrated by 3-Dimensional Fused Images of Computed Tomographic Hepatic Arteriography/Unenhanced Computed Tomography: Prognostic Significance in Patients Who Underwent Transcatheter Arterial Chemoembolization

Objective: To investigate the relation between safety margins (SMs) and treatment efficacy for hepatocellular carcinoma (HCC) by transcatheter arterial chemoembolization (TACE) using 3-dimensional fusion images of computed tomographic (CT) hepatic arteriography and unenhanced CT. Methods: Fifty-three patients with HCC who underwent subsegmental/segmental TACE were followed up. Lipiodol accumulation patterns within the lesion were classified as determined by unenhanced CT immediately after TACE. Lipiodol accumulation patterns around the lesion were classified as determined by 3-dimensional fusion images with special reference to the SMs, which were compared with the local recurrence (LR) rates. Results: Local recurrence was detected in 29 patients (55%) during the follow-up period. When an SM less than 3 mm was defined as insufficient, the LR rates in groups with and without sufficient SMs were 33% (9/25) and 71% (20/28), respectively (P = 0.0136). In 38 nodules with complete Lipiodol accumulation, 10 (63%) of 16 nodules with LR showed the narrow SM (<3 mm), whereas 5 (23%) of 22 nodules without LR showed the narrow SM (P = 0.1341). Multivariate analyses showed that complete Lipiodol accumulation seemed to be an independent prognostic factor (P = 0.0288). Conclusions: 3-Dimensional fusion image was suggested to be valuable for the early detection of viable components within the HCC with insufficient SMs after TACE.