Efficacy of transarterial chemoembolization for hepatocellular carcinoma in interlobar watershed zone of liver: comparison of unilateral and bilateral chemoembolization.

PURPOSE: To evaluate the treatment efficacy of unilateral versus bilateral transarterial chemoembolization for hepatocellular carcinoma (HCC) based on whether the tumor is located across the Cantlie line within the watershed zone of the liver. MATERIALS AND METHODS: Seventy-seven patients with 87 HCCs located in the watershed zone who underwent complete chemoembolization (unilateral, n = 57 [74%]; bilateral, n = 20 [26%]) were included. Tumors located in the watershed zone were further divided into two groups: tumors across the Cantlie line (type A) and tumors not across the line (type B). Comparison of treatment outcomes of unilateral or bilateral chemoembolization for the two groups was performed. The tumor viability (ie, presence of viable component or tumor progression) and position of the viable component on follow-up computed tomography was recorded. RESULTS: Tumor viability rates for type A tumors in the unilateral and bilateral chemoembolization groups were 52.2% and 11.1%, respectively; for type B tumors, they were 23.7% and 11.8%, respectively. The tumor viability rate of type A tumors was significantly higher in the unilateral chemoembolization group than in the bilateral chemoembolization group (P = .05), but there was no significant difference for type B tumors (P > .05). CONCLUSIONS: The tumor viability rate of HCC tumors across the Cantlie line was higher with unilateral chemoembolization group than with bilateral chemoembolization. In patients with HCC across the Cantlie line, embolization of bilateral hepatic arteries may achieve better treatment efficacy.