Apparent diffusion coefficient can predict therapy response of hepatocellular carcinoma to transcatheter arterial chemoembolization.

AIM The goal of this meta-analysis was to assess the apparent diffusion coefficient (ADC) as a pre- and posttreatment (ΔADC) predictive imaging biomarker of response to transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODS SCOPUS database, EMBASE database and MEDLINE library were scanned for connections between pre- and posttreatment ADC values of HCC and response to TACE. Six studies qualified for inclusion. The following parameters were collected: authors, publication year, study design, number of patients, drugs for TACE, mean ADC value, standard deviation, measure method, b-values and Tesla-strength. The QUADAS-2 instrument was employed to check the methodological quality of each study. The meta-analysis was performed by utilizing RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance were used to regard heterogeneity. Mean ADC values and 95% confidence intervals were computed. RESULTS Six studies (n=271 patients with 293 HCC nodules) were included. The pretreatment mean ADC in the responder group was 1.20 x 10-3 mm2/s (0.98, 1.42) and 1.14 x 10-3 mm2/s (0.89, 1.39) in the non-responder group. The analysis of post TACE ADC value changes (ΔADC) revealed a threshold of ≥ 20% to identify treatment responders. No suitable pretreatment ADC threshold to predict therapy response or discriminate between responders and non-responders before therapy could be discovered. CONCLUSION ΔADC can facilitate early objective response evaluation through post-therapeutic ADC alterations ≥ 20%. Pretreatment ADC cannot predict response to TACE.