Intraprocedural Parenchymal Blood Volume Is a Predictor of Treatment Response for Chemoembolization in Hepatocellular Carcinoma: Results of a Prospective Study

Purpose: To evaluate cone-beam parenchymal blood volume (PBV) before and after embolization as a predictor of radiographic response to transarterial chemoembolization in unresectable hepatocellular carcinoma (HCC). Materials and Methods: A phase IIa prospective clinical trial was conducted in patients with HCCs > 1.5 cm undergoing chemoembolization; 52 tumors in 40 patients with Barcelona Clinic Liver Criteria stage B disease met inclusion criteria. Pre- and postembolization PBV analysis was performed with a semiquantitative best-fit methodology for index tumors, with a predefined primary endpoint of radiographic response at 3 months. Analyses were conducted with Wilcoxon signed-rank tests and one-way analysis of variance on ranks. Results: Mean tumoral PBV measurements before and after embolization were 170 mL/1,000 mL +/- 120 and 0 mL/100 mL +/- 130, respectively. Per modified Response Evaluation Criteria In Solid Tumors, 25 tumors (48%) exhibited complete response (CR), 13 (25%) partial response (PR), 3 (6%) stable disease (SD), and 11 (21%) progressive disease (PD). Statistically significant changes in median PBV (Delta PBV) were identified in the CR (P = .001) and PR (P = .003) groups, with no significant difference observed in SD (P = .30) and PD groups (P = .06). A statistically significant correlation between Delta PBV and tumor response was established by one-way analysis of variance on ranks (P = .036; CR, 200 mL/100 mL +/- 99; PR, 240 mL/100 mL +/- 370; SD, 64 mL/100 mL +/- 99; PD, 88 mL/100 mL +/- 129). Conclusions: Intraprocedural PBV can be used as a predictor of response in index HCC tumors of > 1.5 cm.