EVALUATION OF BIPHASIC COMPUTED TOMOGRAPHY AND TUMOR MARKERS IN DETECTING RESIDUAL HEPATOCELLULAR CARCINOMA AFTER MICROWAVE ABLATION

Abstract

Background: HCC is a serious type of liver cancer related to chronic liver diseases and cirrhosis. MWA is a useful procedure for treating this condition; however, when partial ablation takes place, residual tumor cells may be present. Contrast-enhanced CT in two phases, especially the arterial phase, plays a crucial role in identifying such residual HCC tumors. Moreover, AFP and PIVKA-II could give some extra information on the state of the tumor. Thus, this study aimed to find out whether the combined use of the above-mentioned methods could be helpful for detecting residual HCC.

Objective: To assess the effectiveness of biphasic CT and tumor markers (AFP and PIVKA-II) in detecting residual hepatocellular carcinoma after microwave ablation.

Methodology: A cross-sectional design was employed among 72 HCC patients who had previously undergone microwave ablation at the Department of Radiology and Imaging, Aznostics Diagnostic Centre. Patient selection was done using convenience non-probability sampling, while non-HCC lesions and those without complete history were excluded. Correlation between biphasic CT results and serum levels of AFP and PIVKA-II was made using pre-designed data collection sheet and SPSS software. Statistical analysis was performed using Wilcoxon signed rank test, Mann Whitney U test, and Fisher’s exact test. Sensitivity, specificity, PPV, NPV, and accuracy of AFP and PIVKA-II variations were calculated against residual tumor on CT.

Results: In total, the research involved 72 HCC patients undergoing MWA, whose average age was 66.5 years, and the majority of whom were male patients. Residual tumors were found mostly during the arterial phase (18.1%) and were rarely found during the portal venous phase (1.4%). There was a significant reduction in the levels of AFP and PIVKA-II after MWA; however, there was no significant relationship between the reductions and residual tumors. According to the results of the study, the arterial phase of biphasic CT was more important for the diagnosis of residual HCC.

Conclusion: Among the imaging modalities, arterial-phase CT is the most sensitive modality in diagnosing residual HCC following MWA. On the other hand, portal venous phase did not have additional diagnostic significance over arterial-phase CT. Decrease in the serum levels of AFP and PIVKA-II suggested the presence of treatment response, however, it was not sufficient to diagnose residual HCC. There was no significant correlation between larger tumor size and the residual HCC.