Yttrium-90 Radioembolization for Hepatocellular Carcinoma: Virtual Tumor Absorbed Dose as a Predictor of Complete Response.

BACKGROUND/AIM:To evaluate the impact of virtual tumor absorbed dose (vTAD) on tumor response in patients with hepatocellular carcinoma (HCC) treated with yttrium-90 radioembolization. PATIENTS AND METHODS:The institutional review board approved this retrospective single center study, which comprised 100 patients with nodular HCC who underwent yttrium-90 radioembolization between November 2015 and December 2019. The vTAD was calculated assuming that all infused microspheres were distributed only in the tumor. The ability of mean absorbed dose (mAD) and vTAD in predicting complete response were evaluated by receiver operating characteristic (ROC) curve analyses. RESULTS:The mAD was 263.9 Gy ± 125.8, and the mean vTAD was 2005.8 Gy ± 2348.9. In terms of tumor response, 63 patients had complete response, 25 partial response, and 12 stable disease. For predicting complete response, ROC curve analyses revealed that the area under the curve (AUC) value of the vTAD was significantly higher (p<0.001) than that of the mAD. Multivariate analysis revealed that Child-Pugh class A5, unilobar disease, and vTAD (>952 Gy) were significant factors in predicting complete response. CONCLUSION:High vTAD (>952 Gy) plays a significant role in complete response in patients with nodular HCC.