Hepatocellular carcinomas are highly vascular tumors, showing progressive hypervascularity by the process of neoangiogenesis. Tumor angiogenesis is critical for tumor growth as well as metastatic spread therefore, imaging and quantification of tumor neo-angiogenesis is essential for monitoring response to targeted therapies and predicting disease progression. Sorafenib is a molecular targeting agent used for treating hypervascular tumors. This drug is now the standard of care in treatment of patients with advanced hepatocellular carcinoma. Due to its anti-angiogenic and anti-proliferative actions, imaging findings following treatment with Sorafenib are quite distinct when compared to conventional chemotherapeutic agents. Liver MRI is a widely adopted imaging modality for assessing treatment response in hepatocellular carcinoma and imaging features may reflect pathophysiological changes within the tumor. In this mini-review, we will discuss MRI findings after Sorafenib treatment in hepatocellular carcinoma and review the feasibility of MRI as an early biomarker in differentiating responders from non-responders after treatment with molecular targeting agents.
Aged ; Antineoplastic Agents/*therapeutic use ; Carcinoma, Hepatocellular/drug therapy/physiopathology/*radiography ; Female ; Humans ; Liver Neoplasms/drug therapy/physiopathology/*radiography ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Niacinamide/*analogs & derivatives/therapeutic use ; Phenylurea Compounds/*therapeutic use ; Tomography, X-Ray Computed

Bi-phenotypic neoplasm refers to tumors derived from a common cancer stem cell with unique capability to differentiate histologically into two distinct tumor types. Bi-phenotypic hepatocellular carcinoma-cholangiocarcinoma (HCC-CC), although a rare tumor, is important for clinicians to recognize, since treatment options targeting both elements of the tumor are crucial. Imaging findings of bi-phenotypic HCC-CC are not specific and include features of both HCC and CC. A combination of imaging and immuno-histochemical analysis is usually needed to make the diagnosis.
CA-19-9 Antigen/metabolism ; Carcinoma, Hepatocellular/mortality/pathology/radiography ; Cholangiocarcinoma/mortality/pathology/radiography ; Humans ; Liver Neoplasms/mortality/pathology/*radiography ; Magnetic Resonance Imaging ; Phenotype ; Risk Factors ; Survival Analysis ; Tomography, X-Ray Computed ; alpha-Fetoproteins/analysis