Predictability of preoperative F-18-FDG PET for histopathological differentiation and early recurrence of primary malignant intrahepatic tumors

Abstract

Objective The limited studies with F-18-fluorodeoxyglucose (F-18-FDG)-PET reported results and interpretations that differed between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHCC). We investigated the correlation between preoperative PET results and postoperative prognosis, including early (time-torecurrence < 6 months) tumor recurrence, and histopathological tumor differentiation in patients who had undergone surgery for primary malignant intrahepatic tumors, including HCC and IHCC. Materials and methods We retrospectively reviewed 357 patients who had undergone curative surgery for malignant hepatic tumors, including primary HCC or IHCC, other than Klatskin tumors at a tertiary academic hospital between January 2005 and June 2012. All patients had undergone an F-18-FDG PET/computed tomography scan preoperatively and the maximum standardized uptake value of the tumor (maxSUVtumor) and the tumor-to-nontumor SUV ratio (TNR) were calculated from F-18-FDG uptake. Histopathological differentiation grading was confirmed postoperatively. Results Among the patients, 115 cases with primary malignant intrahepatic tumors fulfilled the inclusion criteria. On univariate analysis, preoperative maxSUVtumor and TNR showed a correlation with the overall and early tumor recurrence of HCC, but only maxSUVtumor was associated with overall and early recurrence of IHCC (P < 0.05). When considering postoperative histopathological differentiation, a correlation between maxSUVtumor and TNR with HCC and between maxSUVtumor and IHCC was found (P < 0.05). However, on multivariate analysis, only early recurrence was associated with TNR in HCC and with maxSUVtumor in IHCC. Conclusion A preoperative F-18-FDG PET scan can be considered a useful reference for postoperative tumor recurrence and histopathological differentiation in cases of primary malignant intrahepatic tumors. F-18-FDG PET scan results should be interpreted separately for malignant liver tumors. Nucl Med Commun 36: 319-327 Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.