Quantitative analysis with multiphase contrast-enhanced computed tomography to evaluate residual tumor activity of hepatocellular carcinoma after DEB-TACE

Most hepatocellular carcinomas (HCC) treated by transcatheter arterial chemoembolization with drug-eluting beads (DEB-TACE) are characterized by coagulation necrosis; therefore, it is often difficult to distinguish enhancement in the arterial phase that would lead to false negative evaluation. This study aimed to evaluate the specificity and sensitivity of the difference value of multiphase contrast-enhanced computed tomography (CECT) in predicting residual tumor activity in HCC lesions after DEB-TACE. This retrospective diagnostic study analyzed CECT images of 73 HCC lesions in 57 patients 20 to 40 days (average 28 days) after DEB-TACE treatment at our Hospital from January to December 2019. Postoperative pathology or digital subtraction angiography images were used as references. Residual tumor activity after the first intervention was determined based on the presence of tumor staining in digital subtraction angiography or the postoperative pathological discovery of HCC tumor cells. A significant difference was observed between the active and inactive residual groups in ∆ HU difference between CT values of arterial phase and non-contrast scans (AN, P = .000), difference between CT values of venous phase and non-contrast scans (VN, P = .000), difference between CT values of delay phase and non-contrast scans (DN, P = .000), (difference between CT values of venous and arterial phase scans, P = .001), and (difference between CT values of delay and arterial phase scans, P = .005). No statistically significant difference was observed between the delayed and venous phases (difference between CT values of delay and venous phase scans, P = .361). The area under the curve (AUC) of the ROC curve showed that the diagnostic efficacies in difference in CT value of AN (AUC = 0.976), VN (AUC = 0.927), and DN (AUC = 0.924) were higher, and their cutoff values were 4.86, 12.065, 20.19 HU with their sensitivities of 93.3%, 84.4%, 77.8% and specificities of 100%, 96.4%, and 100%, respectively. difference in CT value values of AN(,) VN, DN, difference between CT values of venous and arterial phase scans and difference between CT values of delay and arterial phase scans can sensitively detect residual tumor activity 20-40 days after DEB-TACE. Thus, more sensitive active residual foci were detected using all 3 enhanced phases rather than only the arterial phase. Quantitative analysis of multiphase CECT can detect residual tumor activity in an early and noninvasive manner, which can provide time for patients to receive early follow-up treatment.