Internal medicine, Yonsei Univeristy College of Medicine.
Purposes:To date, most studies regarding optimal number of target lesions for enhancement criteria for hepatocellular carcinoma (HCC) have focused on cross-sectional analyses of concordance. We investigated optimal number of target lesions for EASL and mRECIST guidelines in predicting overall survival (OS).
We analyzed 254 consecutive treatment-naive HCC patients having at least two measurable target lesions undergoing transarterial chemoembolization. Kappa-values for intermethod agreement of treatment responses were calculated for comparisons between use of maximum of one, two, three, four, or five targets versus use of all target lesions. Prognostic values of radiological assessments according to number of target lesions for predicting OS were expressed as C-index.
By EASL and mRECIST guidelines, kappa-values between responses assessing the longest two, three, four, or five targets and assessing all targets were 0.924, 0.977, 1.000, or 1.000 and 0.907, 0.959, 1.000, or 1.000 respectively, whereas those between responses assessing only one target and assessing all target lesions were 0.723 and 0.666, respectively. C-index when measuring the longest one, two, three, four, five, and all targets was similar, ranging from 0.739 to 0.749 for EASL criteria and from 0.750 to 0.759 for mRECIST. From Cox regression analyses, radiological response from each calculation method demonstrated independently significant effects on OS for both guidelines, regardless of number of target lesions.
Prognostic values for predicting OS were similar regardless of number of target lesions. Assessing the two largest targets rather than only one index lesion is recommended considering high concordances from cross-sectional analyses.