Prognostic value of ^(18)F-FDG PET/CT in liver transplantation for hepatocarcinoma

AIM:To evaluate the prognostic value of pretreatment F D G p o s i t r o n e m i s s i o n t o m o g ra p h y c o m p u t e d tomography(PET-CT) in patients with hepatocarcinoma treated by liver transplantation(LT).METHODS:The authors retrospectively analyzed the data of 27 patients(mean age 58 ± 9 years) who underwent FDG PET-CT before LT for hepatocarcinoma.Mean follow-up was 26 ± 18 mo.The FDG PET/CT was performed according to a standard clinical protocol:4 MBq FDG/kg body weight,uptake 60 min,low-dose non-enhanced CT.The authors measured the SUVmax and SUVmean of the tumor and the normal liver.The tumor/liver activity ratios(RSUVmax and RSUVmean) were tested as prognostic factors and compared to the following conventional prognostic factors:MILAN,CLIP,OKUDA,TNM stage,alphafoetoprotein level,portal thrombosis,size of the largest nodule,tumor differentiation,microvascular invasion,underlying cirrhosis and liver function.RESULTS:Overall and recurrence free survivals were80.7%and 67.4%at 3 years,and 70.6%and 67.4%at 5 years,respectively.According to a multivariate Cox model,only FDG PET/CT RSUVmax predicted recurrence free survival.Even though the MILAN criteria alone were not predictive,it is worth noting that none of the patients outside the MILAN criteria and with RSUVmax<1.15 relapsed.CONCLUSION:FDG PET/CT with an RSUVmax cutoff value of 1.15 is a strong prognostic factor for recurrence and death in patients with HCC treated by LT in this retrospective series.Further prospectivestudies should test whether this metabolic index should be systematically included in the preoperative assessment.

Rationale for the potential use of mesenchymal stromal cells in liver transplantation

Mesenchymal stromal cells(MSCs) are multipotent and self-renewing cells that reside essentially in the bone marrow as a non-hematopoietic cell population, but may also be isolated from the connective tissues of most organs. MSCs represent a heterogeneous population of adult, fibroblast-like cells characterized by their ability to differentiate into tissues of mesodermal lineages including adipocytes, chondrocytes and osteocytes. For several years now, MSCs have been evaluated for their in vivo and in vitro immunomodulatory and ‘tissue reconstruction' properties, which could make them interesting in various clinical settings, and particularly in organ transplantation. This paper aims to review current knowledge on the properties of MSCs and their use in pre-clinical and clinical studies in solid organ transplantation, and particularly in the field of liver transplantation. The first available clinical data seem to show that MSCs are safe to use, at least in the medium-term, but more time is needed to evaluate the potential adverse effects of long-term use. Many issues must be resolved on the correct use of MSCs. Intensive in vitro and pre-clinical research are the keys to a better understanding of the way that MSCs act, and to eventually lead to clinical success.