[Evaluation of the efficacy of oil chemoembolization for hepatocellular carcinoma by computed tomography: a proposal for altering the criteria to indicate the efficacy].

To evaluate the efficacy of oil chemoembolization for hepatocellular carcinoma (HCC), the authors have investigated computed tomography (CT) and pathological findings of 29 resected HCCs from 24 patients and have reached the following conclusions: (1) HCCs that showed a dense retention of Lipiodol within the whole tumor or showed no enhancement on contrast enhanced CT had a significantly higher necrosis rate (p less than 0.01) but were not always easy to evaluate; and (2) in 18 of the 29 tumors that had been observed by CT for 4 to 8 weeks after oil chemoembolization, 91% of those tumors which had a high necrosis rate (greater than or equal to 90%) showed a significant reduction rate that was 20% or greater (p less than 0.05). Based on these results, we propose altering the criteria to allow for the indication of 'partial response', that is, a decrease of 20% or greater in the size of the tumor, confirmed by CT measurement within 8 weeks after oil chemoembolization, and no new lesions or signs of progression in any existing lesion.