TACE is the recommended treatment in intermediate stage of HCC . Different prognostic variables are used to predict the efficacy of TACE in different patients including tumor size, portal vein invasion, alpha-fetoprotein level, Child–Pugh grade and performance status .
TACE induces vascular endothelial growth factor, which promotes angiogenesis and can cause recurrence in the HCC . Cirrhotic liver has parenchymal and perfusional changes that can alter the response to TACE in different liver regions . Areas with atrophy and decreased perfusion can promote better response to TACE. In this retrospective study, we analyzed the relationship between the location of the HCC and its response to TACE to assess whether it can be included as a prognostic factor.
A novel finding in our study was the presence of a significant correlation between the segment of the tumor and its response to TACE. The tumors of the anterior segment showed higher complete response rates. A study reported atrophy of the middle hepatic venous drainage area with atrophy of the anterior segment of the liver . In cirrhotic patients, regenerative nodule compresses the hepatic veins and the middle hepatic vein is the most affected one due to its smaller caliber and longer course compared to the other hepatic veins .
Several studies showed that peripheral area of the liver had less vascularity compared to the central areas, which should promote better efficacy of TACE in peripheral areas. A retrospective study indicated better response for TACE in the peripheral zone of the right lobe and the medial segment in Child–Pugh grade A patients . However, in our study there was no significant difference between central versus peripheral tumors.
We observed a significant correlation regarding the distance between the tumor and the liver capsule and the efficacy of TACE with non-complete response occurring more frequently in the subcapsular region. Peripherally located and exophytic lesions have higher frequency of having extrahepatic collateral vessels; this can affect the efficacy of TACE . It is suspected when there is a defect in Lipidol retention during the TACE procedure or there is recurrence in the follow-up imaging. Interventional radiologist should be familiar with the possible extrahepatic collateral supply and if possible chemoembolization of those vessels should be done .
Our study had several limitations. First, our sample included only HCC with viral etiology. Comparative studies with different etiologies are also necessary. Second, very few lesions were present in the caudate lobe in our study for better assessment of the response to TACE in all the segments.