Performance of gadoxetic acid MRI and diffusion-weighted imaging for the diagnosis of early recurrence of hepatocellular carcinoma.

OBJECTIVE: To determine the diagnostic accuracy and predictive value of gadoxetic acid liver MRI (Gd-EOB-DTPA MRI) alone or in combination with diffusion-weighted imaging (DWI) as a second-line tool for detecting early hepatocellular carcinoma (HCC) recurrence in cirrhotic patients with previous HCC treated with resection or ablation. METHODS: Between 2014 and 2017, we prospectively included 34 cirrhotic patients with complete response to resection and/or ablation of early HCC in whom a new focal lesion enhancing in the arterial phase without washout was detected during follow-up with EC-MRI. After signing the informed consent, all patients underwent DWI and Gd-EOB-DTPA MRI; two readers analyzed signal intensities on each phase of dynamic study and on DWI. The final diagnosis was established by histology or follow-up EC-MRI. We used cross-tabulation to calculate indices of diagnostic accuracy. RESULTS: We evaluated 34 patients (7 women; 73.5% with hepatitis C virus) with a total of 53 new arterial-phase-enhancing foci (median size, 10 [IQR 9-14] mm). The final diagnosis, reached by histopathology in 15 (35.7%) lesions and EC-MR follow-up in 27 (64.3%), was HCC in 42 (79.2%) and benign conditions in 11 (21.8%). Hepatobiliary-phase hypointensity on Gd-EOB-DTPA MRI plus hyperintensity on DWI yielded 54.8% sensitivity, 90.9% specificity, 95.8% positive predictive value, and 34.5% negative predictive value for diagnosing HCC recurrence. CONCLUSION: Among potential indices, combining hypointensity on hepatobiliary-phase Gd-EOB-DTPA MRI and hyperintensity on DWI has the highest specificity and positive predictive value to optimally detect HCC recurrence prior to confident diagnosis by conventional imaging criteria on EC-MRI in cirrhotic liver. KEY POINTS: • In patients at risk of HCC recurrence, the use of gadoxetic acid liver MRI and DWI may improve the differentiation of unspecific new arterial-enhancing foci from early hypervascular HCC recurrence in patients with non-conclusive findings on extracellular liver MRI. • Combined findings on hepatobiliary-phase gadoxetic acid-enhanced liver MRI and DWI had high specificity (90.9%) and positive predictive value (95.8%) for detecting early hypervascular HCC recurrence, but limited sensitivity. • Combining hepatobiliary-phase hypointensity on gadoxetic acid MRI and hyperintensity on diffusion-weighted imaging allows early diagnosis of hypervascular hepatocellular carcinoma and may help select patients for salvage therapy.

Diagnosis of hepatic nodules 20 mm or smaller in cirrhosis: Prospective validation of the noninvasive diagnostic criteria for hepatocellular carcinoma.

This study prospectively evaluates the accuracy of contrast-enhanced ultrasound (CEUS) and dynamic magnetic resonance imaging (MRI) for the diagnosis of nodules 20 mm or smaller detected during ultrasound (US) surveillance. We included 89 patients with cirrhosis [median age, 65 years; male 53, hepatitis C virus 68, Child-Pugh A 80] without prior hepatocellular carcinoma (HCC) in whom US detected a small solitary nodule (mean diameter, 14 mm). Hepatic MRI, CEUS, and fine-needle biopsy (gold standard) (FNB) were performed at baseline. Non-HCC cases were followed (median 23 months) by CEUS/3 months and MRI/6 months. FNB was repeated up to 3 times and on detection of change in aspect/size. Intense arterial contrast uptake followed by washout in the delayed/venous phase was registered as conclusive for HCC. Final diagnoses were: HCC (n = 60), cholangiocarcinoma (n = 1), and benign lesions (regenerative/dysplastic nodule, hemangioma, focal nodular hyperplasia) (n = 28). Sex, cirrhosis cause, liver function, and alpha-fetoprotein (AFP) levels were similar between HCC and non-HCC groups. HCC patients were older and their nodules significantly larger (P < 0.0001). First biopsy was positive in 42 of 60 HCC patients. Sensitivity, specificity, and positive and negative predictive values of conclusive profile were 61.7%, 96.6%, 97.4%, and 54.9%, for MRI, 51.7%, 93.1%, 93.9%, and 50.9%, for CEUS. Values for coincidental conclusive findings in both techniques were 33.3%, 100%, 100%, and 42%. Thus, diagnosis of HCC 20 mm or smaller can be established without a positive biopsy if both CEUS and MRI are conclusive. However, sensitivity of these noninvasive criteria is 33% and, as occurs with biopsy, absence of a conclusive pattern does not rule out malignancy. These results validate the American Association for the Study of Liver Disease (AASLD) guidelines.

Initial response to percutaneous ablation predicts survival in patients with hepatocellular carcinoma.

Outcome predictors in patients with hepatocellular carcinoma (HCC) who are treated with percutaneous ablation are ill defined, and it is unknown if successful therapy is associated with improved survival. In our study, 282 cirrhotic patients with early nonsurgical HCC were treated with percutaneous ablation during a 15-year period. Single tumors were seen in 244 patients, and 2 to 3 nodules were seen in 38 patients. Initial complete response was achieved in 192 patients and was independently related to the size of the main tumor (P = .015) and tumor stage (P = .0001) (< or =2 cm, 96%; 2.1-3 cm, 78%; >3 cm, 56%; 2-3 nodules, 46%). At the end of follow-up, 80 patients presented sustained complete response. The 1-, 3-, and 5-year survival rates were 87%, 51%, and 27%, respectively. The independent predictors of survival were Child-Turcotte-Pugh class (P = .0001) and initial complete response (P = .006). Child-Turcotte-Pugh class A patients with initial complete response achieved 42% survival at 5 years; this figure increased to 63% in patients with tumors 2 cm or smaller. In conclusion, our results demonstrate that initial complete response to percutaneous ablation is associated with an improved survival in both Child-Turcotte-Pugh class A and B patients with nonsurgical HCC. Accordingly, initial complete tumor necrosis should be considered a relevant therapeutic target irrespective of tumor size and liver function.