Efficacy of RECIST and mRECIST criteria as prognostic factors in patients undergoing repeated iodized oil chemoembolization of intermediate stage hepatocellular carcinoma

Background: Given that transarterial chemoembolization (TACE) is usually a repeated procedure for treatment of hepatocellular carcinoma (HCC), repeated radiologic response assessments rather than a single time point assessment may have different clinical implications through the repeated course of TACE. Purpose: To evaluate the efficacy of RECIST and mRECIST criteria as a survival predictor across early time points after repeated TACE of HCC. Material and Methods: Ninety-eight patients with intermediate stage HCC received repeated iodized oil TACE. Treatment response was assessed according to RECIST and mRECIST criteria at 1, 3, and 6 months after initial TACE. Cox proportional model was used for survival analysis and the predicting power of each time point response was evaluated with C-statistics and time-dependent area under the receiver operating characteristic curve (AUC). Intermethod agreement was assessed with the coefficient. Results: mRECIST was not applicable in 15 patients because of patchy uptake of iodized oil after TACE. On multivariate analysis, responders at 6 months by RECIST, responders at 3 months, and 6 months by mRECIST showed better survival than non-responders (P<0.05). Predicting power of response criteria improved over time and mRECIST at 6 months showed the best performance. The degree of agreements was poor or fair between RECIST and mRECIST. Conclusion: mRECIST predicted long-term survival as early as 3 months after TACE of intermediate stage HCC. The predicting power of the uni-dimensional response criteria tended to be stronger over time.