Clinical usefulness of 18 F ‐fluorodeoxyglucose positron emission tomography/computed tomography for patients with primary liver cancer with special reference to rare histological types, hepatocellular carcinoma with sarcomatous change and combined hepatocellular and cholangiocarcinoma

Aim The role of 18 F ‐fluorodeoxyglucose positron emission tomography ( FDG‐PET ) in the diagnosis and staging of primary liver cancer has been demonstrated in several reports. However, no preoperative evaluations of sarcomatous hepatocellular carcinoma ( HCC ) and combined hepatocellular and cholangiocarcinoma (c HCC ‐ CC ) with FDG‐PET have been reported so far. Methods Fifty‐three HCC patients and three c HCC ‐ CC patients who received liver resection or living‐donor liver transplantation were enrolled in this study. All 56 patients had undergone preoperative FDG‐PET , and a total of 67 HCC and three c HCC ‐ CC were analyzed histologically. The relationship between clinicopathological features and the maximum standardized uptake value ( SUV max) of tumors were evaluated. Results The detection rate of HCC by FDG‐PET was 43.3 %, and the sensitivity of FDG‐PET for the detection of HCC was significantly associated with tumor differentiation, tumor size and microvascular invasion. All three c HCC ‐ CC were detected by FDG‐PET . The SUV max values of the three sarcomatous HCC ( SUV max 14.1, 18.6 and 25.0) and the three c HCC ‐ CC ( SUV max 9.9, 12.0 and 13.0) were higher than that of the poorly differentiated HCC (mean SUV max 5.7 ± 2.3). Conclusion SUV max may be a useful diagnostic tool for the preoperative evaluation of the aggressiveness of primary liver cancers such as sarcomatous HCC and c HCC ‐ CC .