Dual Energy CT- Surrogate Quantitative Marker of Response to Targetted treatment in HCC

Abstract

Background and Aim: Dual energy CT (DECT)– novel CT imaging technique at two different energies, can be used to discriminate between different materials (e.g., fat, calcium, iodine, and water), which are not allowed by conventional CT. The images reconstructed from these differential data, including iodine concentration maps, may provide diagnostic information beyond that obtainable with conventional CT Aim: To evaluate the supplementary value of dual energy CT to assess response in cirrhotic patients with HCC following targeted therapy. Methods: 20 patients with targeted therapies for dual energy CT (TACE/TARE/RFA) were evaluated. Iodine uptake(IU), derived from the iodine-based material-decomposition image and the iodine concentration ratio on the dual energy CT acquired during early portal venous phase was calculated by drawing regions of interest within the treated lesion, at the edge and within the surrounding liver parenchyma. Quantification of IU (absolute value for total IU (mg) and volume-normalized IU (mg/ml)) was based on semi-automatic tumor volume segmentation compared to the background liver. The decrease compared with baseline was calculated. Results: The mean normalized IU per patient within the treated lesion compared to the cirrhotic liver parenchyma -31%. Total IU per patient, combining both normalized IU and volume, showed the most pronounced decrease. Conclusion: DECT enables objective, easy and fast parameterization of tumor size and contrast medium uptake. DECT provides a quantitative method with which to analyze the treated lesions in the cirrhotic liver. The authors have none to declare.