458 TREATMENT OF HEPATITIS C FOLLOWING LIVER RETRANSPLANTATION

Abstract

Aim: Recent studies suggest that a positive 18FDG PET-CT is associated with an increased risk of tumour recurrence and death after LT for HCC. Intensity of 18FDG uptake was also shown to be correlated to tumour differentiation and micro-vascular invasion. The aim of this pilot study was to assess the role of 18FDG PET-CT as a predictor of drop-out from the waiting list in patients listed for HCC. Patients and Methods: Between October 2006 and August 2008, 20 patients were evaluated by the mean of 18FDG PET-CT at listing for LT for HCC and blindly reviewed by an independent operator. 18FDG uptake was quantified by calculating SUV (standardized uptake value) in the tumour and considered positive when ratio T/NT was >1. The relationship between PET-CT patterns, the rate of drop-out for tumour progression and pathological characteristics of the explanted liver were analysed. Results: Among 20 PET-CT, 8 were considered positive with an average SUV of 3.9±1.0 and a ratio between the tumour and the adjacent non tumour liver of 1.5±0.4. Among the 8 patients presenting with a positive PET-CT, 4 pts were transplanted (50%), and the other 4 pts were dropped out because of tumour progression. PET-CT was negative in the remaining12 patients at listing. Only 1 patient was excluded from the list for tumour progression (8% vs. 50% if PET positive, p = 0.03). Two patients are still waiting LT on the list. In transplanted patients (n = 13), pathological characteristics of the explanted liver of patients with positive PET-CT at listing tended to be more frequently outside the Milan criteria (50% vs 28%; ns), to have a higher rate of vascular invasion (75% vs 42%; ns) and a poorer grade of tumour differentiation ( moderate: 100% vs 71%; ns). Follow-up was too short to evaluate the impact of positive PET on tumour recurrence after LT. Conclusion: The positivity of the 18FDG PET-CT at listing is strongly associated with the rate of drop-out for tumour progression. 18FDG PETCT seems a promising tool in pre-LT patient evaluation. Its role must be clarified by a larger prospective study yet.