Follow-up CT measurement of liver malignoma according to RECIST and WHO vs. volumetry

Purpose: Intraindividual comparison of quantitative malignant liver tumor response analysis using computed tomography. The RECIST and WHO evaluation results were compared to the volumetry results. Materials and method: Consecutive CT follow-up investigations (portal-venous phase, collimation 3 mm, increment 2 mm) of 82 patients were analyzed retrospectively. The median interval was 56 (30 - 455) days. The patients showed a total of 198 (median 3, range 1 - 5) malignant liver lesions. The evaluation was performed by 2 radiologists using the OncoTREAT software (Mevis) in consensus. The results were classified according to RECIST (Response Evaluation Criteria in Solid Tumors, stable disease: - 30 % to + 20 %) and WHO (stable: - 50 % to + 25 %) and compared to the volumetric analysis (stable: - 65 % to + 44 %). Both the continual follow-up changes and the classified results (complete and partial remission, no change and progression) were analyzed. Results: The classified RECIST and WHO results agreed with the volumetric analysis in 71/82 (87 %) of cases κRECIST = 0,699, κWHO = 0,741. This included different patients thus showing the agreement between the RECIST and WHO evaluations in 68/82 (83 %) cases (κ = 0,656). The estimation of the relative tumor development was clearly different in all procedures. Relative tumor changes are not directly comparable because of underlying one-, two- and three-dimensional structures. (orig.)