Role of Positron Emission Tomography-Computed Tomography (PET-CT) in Evaluation of Hepato-Cellular Carcinoma

Background: Globally HCC appeared to be the third main reason of mortality associated with cancer.  According to degree of differentiation, HCC can be classified into four grades. PET/CT represents a functional imaging technique that offers metabolic insights into the tumor. It may play a substantial turn in prediction of biological behavior of HCC, predicting tumor grade and presence of microvascular invasion. Aim of the work:  This work aimed to assess the utility of 18F-FDG PET/CT in identification of primary hepatocellular carcinoma (HCC) and in predicting its histological grade. Methods: A total of 52 patients with established HCC were included in this prospective study, with a mean age of 62.38 ± 7.73 years. All participants were subjected to 18F-FDG PET/CT and triphasic CT imaging. The result of histopathology was our standard of reference. The concordance between PET/CT and triphasic CT regarding lesion detection was evaluated. Additionally, the diagnostic sensitivity of PET/CT in detecting primary HCC was determined. The ability of PET-CT in differentiation between different grades of HCC was assessed. Results:  PET-CT had 84.6% sensitivity in detection of primary HCC with moderate agreement between PET-CT and triphasic CT in detection of HCC (k= 0.588). Cut off SUV max value of 5.75 yielded 75% sensitivity, 88.9% specificity, 92.3% PPV, 61.5% NPV, 76.9% accuracy and 0.951 AUC in differentiating well, moderately differentiated HCCs from poorly differentiated HCCs. Conclusion: PET-CT showed high sensitivity in detection of primary HCC and can predict histological grade of HCC.