Iodized oil uptake assessment with cone-beam CT in chemoembolization of small hepatocellular carcinomas

Abstract

Aim: To evaluate the utility of assessing iodized oil uptake with cone-beam computed tomography (CT) in transarterial chemoembolization (TACE) for small hepatocellular carcinoma (HCC).

Methods: Cone-beam CT provided by a biplane flat-panel detector angiography suite was performed on eighteen patients (sixteen men and two women; 41-76 years; mean age, 58.9 years) directly after TACE for small HCC (26 nodules under 30 mm; mean diameter, 11.9 mm; range, 5-28 mm). The pre-procedural locations of the tumors were evaluated using triphasic multi-detector row helical computed tomography (MDCT). The tumor locations on MDCT and the iodized oil uptake by the tumors were analyzed on cone-beam CT and on spot image directly after the procedures.

Results: All lesions on preprocedural MDCT were detected using iodized oil uptake in the lesions on cone-beam CT (sensitivity 100%, 26/26). Spot image depicted iodized oil uptake in 22 of the lesions (sensitivity 85%). The degree of iodized oil uptake was overestimated (9%, 2/22) or underestimated (14%, 3/22) on spot image in five nodules compared with that of cone-beam CT.

Conclusion: Cone-beam CT is a useful and convenient tool for assessing the iodized oil uptake of small hepatic tumors (< 3 cm) directly after TACE.

Figure 1

A 47-year-old man with hepatocellular carcinoma in S2 for 2nd TACE. A: Preprocedural late arterial phase MDCT scan reveals hypervascular HCC near the diaphragm (arrow); B: Left gastric angiogram shows aberrant left hepatic artery with no tumor staining in suspected area; C: Tumor staining (arrow) and feeder artery are found after acquiring MIP image from cone-beam CT hepatic arteriography (Cone-beam CTHA); D: Cone-beam CT directly after TACE shows good grade iodized oil uptake in S2 (arrow); E: Spot image shows subtle lipiodol uptake near the left hemidiaphragm (arrow), but nodular iodized oil uptake is not observed.

Figure 2

A 52-year-old man with HCC in S2 for 2nd TACE. A, B: Early arterial phase (A) and delayed phase (B) of MRI reveals nodule (arrow) in segment 2 with no enhancement (arrow); C: Cone-beam CT after TACE shows poor grade of iodized oil uptake by the tumor; D: Early arterial phase of MDCT shows washout of iodized oil uptake near nodule, but no enhancing portion within the nodule 3 mo later; E: Left hepatic angiogram during TACE reveals no tumor and feeding artery 1 mo later; F, G: Cone-beam CT with (F) and without (G) hepatic arteriography shows small enhancing nodule (arrow) in the nodule; H, I: Cone-beam CT after infusion of emulsion (H) shows excellent grade iodized oil uptake by the nodule (arrow). This case shows typical “nodule-in-nodule” appearance of HCC, but spot image (I) did not distinguish nodular uptake.