Combined positron emission and computed tomography (PET-CT): potential of the method in differential diagnosis of hepatic masses, and also in detection of the primary sites at suspicion of metastatic malingancies in the liver

Aim: to assess the scope and potential of combined PET-CT in differential diagnosis of hepatic masses and in detection of the primary site at suspicion on metastatic malignancies in the liver. Material and Methods. We selected a group of patients (within a 3-year period) in whom hepatic masses were detected by the means of PET-CT (567 patients in total). Of this group, 33 patients did not have the histologically verified diagnosis of cancer. All patients were subjected to combined PET-CT with 18F radiotracer - fluorodeoxyglucose - in accordance with “Whole Body” standard protocol with multiphase contrast study. Results. Metabolically active lesions were identified in 23 patients: in 1 patient - alveococcosis (due to anamnesis), in 22 pa-tients - metastatic lesions. The primary tumor was detected in 9 patients. In the remaining 10 patients metabolically inactive lesions were revealed: in 1 patient, based on MSCT findings, we suspected high-grade differentiated hepatocellular carcinoma (HCC) with metastatic lesions of the liver parenchyma, in 1 patient - differential diagnosis between HCC and hepatocellular ade-noma (GTSA) (histologically verified, GTSA), in 4 patients - liver hemangiomas and in 4 patients - the assumption of the benign nature of the process in the absence of metabolic activity, as well as any other foci. Conclusions. So, combined PET-CT should be performed for patients with the purpose of differential diagnosis of the liver lesions. Herewith, the identification of the primary tumor in patients with metastases to the liver is about 40 percent, depending on the histological type of the primary tumor, size of the primary tumor and the plurality of secondary lesions of various organs and systems.