Evaluation of Newly Developed Small (< or = 20 mm) Enhancing Nodules on the Arterial Phase CT after Transcatheter Arterial Cheomoembolization in Patients with Hepatocellular Carcinoma

ABSTRACT

PURPOSE: We assessed the clinical significance of newly developed small (< or = 20 mm) early-enhancing hepatic nodules on arterial phase CT after performing transcatheter arterial cheomoembolization (TACE) in patients suffering with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: We searched for the radiologic reports that showed small early enhancing nodule (< or = 20 mm) on the arterial phase imaging of follow-up CT after performing TACE. Thirty-seven lesions in 30 patients had round or oval shaped nodules and the numbers of nodule for one patient was less than five. We classified the nodules by size, location and the decreased attenuation seen on the portal venous phase. The latest follow-up CTs were reviewed to assess the nodules for the final diagnosis. All the follow-up CTs were two-phase spiral CT scans. RESULTS: Twenty-five (67%) of the 37 nodules were recurred HCC, as was determined on the basis of their interval growth and lipiodol uptake after TACE. Among the 37 nodules, seven (18%) disappeared on the latest follow-up CT and they were considered as definite pseudolesions. The remaining five (15%) were stable in size or they decreased in size, and they were considered as probable pseudolesions. The mean size of the nodules on initial CT was 11 mm. The mean size of the malignant nodules was 11+/-4.2 mm and that of the benign pseudolesions was 9+/-4.9 mm. The nodules located on the hepatic surface were possible to definite benign pseudolesions (p<0.05). All ten low attenuated nodules seen on the portal phase were HCCs. CONCLUSION: When seen on the follow-up CT scans of HCC patients after performing TACE, the newly developed small early-enhancing nodules were considered to have high potential of being HCC by their locations and enhancing patterns.