Efficacy of cone-beam computed tomography during transcatheter arterial chemoembolization for hepatocellular carcinoma

Cone-beam computed tomography (CBCT) using a flat-panel detector is an alternative method of obtaining cross-sectional images. This technique is now being used during transcatheter arterial chemoembolization (TACE) for inoperable hepatocellular carcinoma (HCC). Several CBCT techniques are performed to detect HCC lesions: CBCT during portography (CBCTAP), CBCT during hepatic arteriography (CBCTHA), CBCT after iodized oil injection (LipCBCT), CBCT during arteriography (CBCTA) of extrahepatic collaterals. Almost all HCC lesions can be detected using these CBCT images. Three-dimensional arteriography using maximum intensity projection from CBCTHA images can identify the tumor-feeding branch. In particular, this technique is useful when the tumor stain cannot be demonstrated on arteriography. In addition, dual-phase CBCTHA can improve the diagnostic accuracy for hypervascular HCCs because corona enhancement can be detected around the tumor. To monitor the embolized area during TACE, selective CBCTHA or LipCBCT at the embolization point is useful. Two sequential CBCT scans without and with contrast material injection is also useful to confirm each embolized area of two vessels. Furthermore, CBCTA can prevent nontarget embolization. Although the image quality of CBCT is low compared to that of conventional CT, CBCT provides useful information that helps perform TACE for HCCs safely and effectively.