Functional imaging of hepatocellular carcinoma using diffusion-weighted MRI and 18F-FDG PET/CT in patients on waiting-list for liver transplantation

Abstract

BackgroundTo compare the apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) with the standardized uptake values (SUV) measured by18F-FDG-PET/CT in naïve hepatocellular carcinoma (HCC) nodules, and to determine whether these markers are associated with tumours at high-risk of aggressiveness.MethodsFrom 2007 to 2010, all patients with HCC on the waiting list for liver transplantation and who underwent both FDG-PET/CT and 1.5-T DWI-MRI (b values: 0, 200, 400, and 800 s/mm2) were included in this institutional review board-approved retrospective study. Tumour size, tumour ADC, tumour-to-liver ADC ratio (ADCT/L), maximal tumour SUV and tumour-to-liver SUV ratio (SUVT/L) were measured and compared to serum alpha-fetoprotein (AFP) levels, tumour size and differentiation grade on explanted specimens.ResultsA total of 37 HCC nodules in 28 patients were available for correlation between MRI and PET/CT, 7 of which (in 7 patients) showed a SUVT/L > 1.15. We did not find any correlation between tumour ADC or ADCT/L and tumour SUV or SUVT/L. To note, SUVT/L was positively correlated with AFP levels (R = 0.95, P ≤ 0.0001), while ADCT/L was not (P = 0.73). Twenty-four patients (with 32 nodules) underwent liver transplantation. In this subgroup, an increased SUVT/L ratio was associated with larger tumours (average size, 32 ± 14 mm; range, 18–60 mm; P < 0.0001) and with poor differentiation on pathology (grades 3 and 4; P = 0.04), while ADCT/L was neither associated with tumour size or differentiation grade.ConclusionsADC and SUV measures in HCC nodules are not correlated. SUVT/L ratio correlates with AFP levels, tumour size and poor differentiation, and should probably be integrated as a co-variable in a predictive outcome model of patients on the waiting-list for liver transplantation.

Diffusion weighted magnetic resonance imaging of liver: Principles, clinical applications and recent updates

“…The association of ADC and histopathological grades has shown conflicting results in few other studies[ 55 , 56 ]. This might be a result of tumor necrosis, as it can result in reduced cellularity and increased ADC in high-grade lesions.…”

Hepatocellular carcinoma: when is liver transplantation oncologically futile?

“…The challenge remains to define an exact cut-off that excludes patients from LT. CT is a non-invasive surrogate of tumor biology. Increased 18 F-FDG uptake on PET is correlated with higher AFP concentrations, larger tumor size, poor differentiation and microvascular invasion (49)(50)(51)(52). In a study correlating results from histological evaluation and PET imaging, a high level of 18 F-FDG accumulation showed a sensitivity of 84.1% and a specificity of 75.0% for distinguishing between well-and poorly differentiated HCC (53).…”

Pan-Asian adapted ESMO Clinical Practice Guidelines for the management of patients with intermediate and advanced/relapsed hepatocellular carcinoma: a TOS–ESMO initiative endorsed by CSCO, ISMPO, JSMO, KSMO, MOS and SSO

“…No benefit of carrying out FDG-PET scans as a staging modality has been demonstrated, despite some evidence of a correlation between higher FDG uptake and poor differentiation, tumour size, serum AFP levels and microvascular invasion ('recommendation 3c'). 49,50 As described in the ESMO 2018 guidelines for HCC 3 and 'recommendations 3def' above, liver function is classically assessed using the Child-Pugh scoring system (serum bilirubin, serum albumin, ascites, prothrombin time and hepatic encephalopathy) [III, A], and within the Child-Pugh A patient group, measurement of the ALBI is able to divide patients into those with good prognosis (ALBI 1) and those with poor prognosis (ALBI 2), with median survivals of 24.5 versus 14.7 months in the European/US cohort; 85.6 versus 54.8 months in the Japanese cohort and 20.0 versus 8.1 months in the Chinese cohort [IV, B]. 44 Clinically significant portal hypertension is excluded if the patient has a platelet count of >150 Â 10 9 cells/l and a non-invasive liver stiffness measurement of <20 kPa.…”