ROLE OF DWI IN EVALUATION OF HCC AFTER RADIOFREQUENCY ABLATION COMPARED TO DYNAMIC MRI USING MRI (3 tesla)

Abstract

H epatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has a poor prognosis unless treated. Radiofrequency ablation therapy of HCC lesions is promising treatment option for patients who are not eligible for surgery. Monitoring tumor response after RFA treatment is an increasingly important task in oncologic imaging. Early favorable response indicates effectiveness of therapy while early identification of treatment failure is also critical in patient management as further treatment will be mandatory before disease progression. Recent advances in the development of functional MR imaging techniques have provided the ability to detect microscopic changes in tumor microenvironment and micro-structure that allow better assessment of treatment response. Dynamic contrast enhanced MR imaging can assesses the change in the tumor vascularity and perfusion. DW MRI in the liver is a relative new and increasingly used imaging technique. It has the advantage that it can be obtained during a single breath-hold; it provides unique information that reflects tissue cellularity and organization. The ADC maps can also provide quantitative measurements of tissue water diffusibility, which can be used not only for disease assessment, but also for the evaluation of disease response to treatment. Forty patients with HCC underwent RFA treatment were included in this study. We assessed and classified our patients according to morphological changes (size and signal intensity at T1, T2 and diffusion weighted images), quantitative diffusion analysis (ADC measurement), enhancement pattern in the dynamic study.