Evaluation of Hcc in Re-Sponse to Transcatheter Arterial Chemoemboliza-Tion Combined Radiofre-Quency Ablation With3.0TMRI
|Keywords||cancer liver cells transcatheter arterial chemoembolization radiofrequency ablation magnetic resonance imaging|
Objective To evaluate the added value of diffusion-weighted imaging （DWI） combined with conven-tional magnetic resonance imaging （MRI） in the detection of new, very small hepatocellular carcinoma le-sions （≤1cm） in patients with hepatocellular carcinoma following interventional therapy compared to con-ventional MRI alone. Investigate3.0T MRI characteristics in patients with HCC after transcatheter arterialchemoembolizstion （TACE） combined radiofrequency ablation （RFA）. Methods After interventional ther-apy,60patients with hepatocellular carcinoma underwent conventional MRI and DWI with a b-value of0and700s/mm2. Twentyone new, small hepatocellular carcinoma lesions were confirmed in16patients atfollow-up MRI. According to the Barcelona Clinic Liver Cancer （BCLC） staging classification,very-earlystage HCCs are defined as single nodules <2cm in a well-compensated cirrhotic liver withoutportal hypertension. All patients were performed with TACE combined with RFA, TCAE was done withSeldinger technique and the right femoral artery puncture, after5-7days,the RITA radiofrequency ablationpuncture needle puncture treatment of cancer treatment. Twentyone new, small hepatocellular carcinomalesions were confirmed in16patients at follow-up MRI. Two observers independently retrospectively ana-lysed the two imaging sets in random order. The diagnostic performance using each imaging set was eva-luated by received operating characteristic curve analysis. The diagnostic performance of each imaging setfor all of the very small HCC lesions were evaluated by each observer using receiver operating characteris-tic （ROC） curve analysis. To minimize any learning bias, a2-week interval was scheduled between the twoimaging sets for one radiologist. Each observer recorded the presence and segmental location of the lesions,assigning each a confidence level on a five-point scale:1=definitely not present;2=probably not present;3=equivocal;4=probably present; and5=definitely present. The positive calculations were based on onlythose lesions awarded a confidence rating of4or5. A third radiologist correlated the scored lesions withthe standard of reference on the basis of the description. All patients underwent repeat TACE after the newlesions were found. The presence of new HCC was finally confirmed with an additional combination ofcharacteristic angiographic findings and iodized oil CT. During March2010to December2012，routine andcontrast enhanced dynamic MRI as well as DWI （b=0,700s/mm2） were performed in42patients with pri-mary liver cancer after TACE combined with RFA. According to postoperative AFP values and MRI con- trast enhancement and other indicators of treatment efficacy, the cases were divided into three groups （good,moderate, poor）. MR imaging characteristics were analyzed at1month after interventional therapy. Re-sults Twenty-one new, very small hepatocellular carcinoma lesions found in16patients was confirmed asthe final result. The area under the receiver operating characteristic curve of the DWI/conventional MRIcombination （observer1,0.952; observer2,0.976） and conventional MRI images alone （observer1,0.905;observer2,0.905） were statistically significant. The kappa value of the DWI/conventional MRI combina-tion was0.884, and that of conventional MRI was0.722. Among the21lesions,100%of the lesions wereboth recognized by two independent reviewers on DWI and conventional MRI, while only76%and71%of the lesions were regarded as very small hepatocellular carcinomas on conventional MRI,81%and86%of the lesions were regarded on DWI. AFP values of good group showed normal and no abnormal elevation.The edge of the lesions in good group showed hyperintense on T1WI, and the lesions showed low signal onopposed-phase, heterogeneously low signal on T2WI and hypointense or mixed hypo-and iso-intense onDWI. No enhancement were found and the edge of lesions was smooth and clear in good group. AFP val-ues of moderate and poor groups showed abnormal elevation. The edge of the lesions in moderate and poorgroup showed low and mixed signal intensity on T1WI, and the lesions showed low signal on op-posed-phase, heterogeneously high signal on T2WI and heterogeneous hypointensity or hypointensity onDWI. Nodular and ring enhancement were found at the edge of the lesions, new little lesions and tumorthrombus were found in some cases. Conclusion Due to the higher detection rate of new subcentimetrelesions in hepatocellular carcinoma patients following interventional therapy, DWI could be consideredcomplementary to conventional MRI in the diagnosis of hepatocellular carcinoma. MRI could be used toevaluate whether residual or recurrence in patients with hepatocellular carcinoma after TACE combinedRFA, and further guided for the clinical choice.