Role of [18F] fludeoxyglucose positron emission tomography in the selection of liver transplantation candidates in patients with hepatocellular carcinoma

BACKGROUND: The Milan criteria are widely accepted among many centers. However, patients with hepatocellular carcinoma beyond the Milan criteria might still benefit from liver transplantation (LT) when tumor itself is not aggressive. [F-18] fluorodeoxyglucose positron emission tomography/computed tomography imaging could provide useful information of tumor behaviors, which is helpful to predict the prognosis for many tumors. METHOD: In order to determine its role in candidate selection for LT, we therefore retrospectively analyzed 103 recipients with preoperative positron emission tomography (PET) findings. RESULTS: Positive PET findings (PET+) were significantly associated with tumor nodule numbers (P=0.013), tumor grade (P=0.025), macro- (P=0.002) and micro-vascular invasion (P=0.002), as well as the Milan criteria (P=0.018). PET+ patients had significantly increased risk of tumor recurrence post-LT compared to PET negative (PET-) patients (P=0.007). The 1-, 3-, and 5-year overall survival rate of PET- patients were 96.0%, 87.2% and 76.2%, compared to 74.7%, 55.4% and 49.9% in PET+ patients, respectively (P<0.05). The 1-, 3-, and 5-year recurrence-free survival rate of PET- patients were 91.8%, 81.9% and 76.0%, compared to 70.1%, 39.3% and 21.9% in PET+ patients, respectively (P<0.05). Recipients within the Milan criteria showed comparable 1-, 3-, and 5-year survival rates in comparison with those beyond the Milan criteria with a PET- findings (1-, 3-, and 5-year overall survival rates, 97.5%, 83.3%, and 83.3% vs 90.0%, 80.0%, and 66.7%, P= 0.123; 1-, 3-, and 5-year recurrence-free survival rates, 95.1%, 73.1%, and 73.1% vs 90.0%, 78.8%, and 65.6%, P=0.148). CONCLUSIONS: Certain patients with hepatocellular carcinoma and negative PET findings, who have exceeded the Milan criteria, are also eligible candidates for LT. Preoperative PET/CT imaging is an important marker, which should be incorporated in extended candidate selection criteria for LT.