Aim. To conduct a comparative analysis of “in vivo” and “in vitro” radionuclide methods for the differential diagnosis of focal liver lesions, namely, malignant lymphoma, hepatocellular carcinoma, metastatic lesion, hemangioma, and focal nodular hyperplasia of the liver.

Materials and methods. 122 patients (66 men and 56 women) aged 29-77 years with malignant liver lymphoma, hepatocellular carcinoma, metastatic liver damage, hemangioma and focal nodular hyperplasia of the liver were examined by radionuclide methods “in vivo” and “in vitro”. The “in vivo” research is represented by static hepatoscintigraphy, which was performed on a scintillation gamma camera SPECT-1, which is equipped with EVM, in 3 projections – direct, right lateral and posterior.  As a radiopharmaceutical preparation, 99mTs colloid was used at the rate of 1 MBq/kg of the patient’s weight. The method did not require special training of the patients. For in vitro diagnosis of tumor markers alpha-fetoprotein, cancer-embryonic antigen, specific antigen 19-9, beta-2 microglobulin and thymidine kinase, radioimmunological analysis was used on the radioimmunological counter “Gamma-12” with the help of appropriate kits from the company “Immunotech” ( Czech Republic). The patients previously underwent ultrasound of the liver, where all of them were found to have both single and multiple nodes of heterogeneous structure from 1.0 cm to 6.0 cm in diameter, with uneven clear contours, increased echogenicity with hypo- or hyperechoic inclusions.

Results. The scintigraphic picture of various focal lesions of the liver did not have specific signs characteristic of one or another pathology. Single nodular lesions of the liver (hepatocellular carcinoma, lymphoma, single metastases, hemangioma) appeared on the scintiphoto as an “accumulation defect” of the drug in one of the liver segments, almost indistinguishable from each other. Multiple focal lesions of the liver (metastases or focal nodular hyperplasia) on the scintiphoto looked like “cold zones” without characteristic signs of one or another pathology. Thus, it is not appropriate to use this radionuclide method for differential diagnosis of focal liver lesions. As for the determination of tumor markers, other results were obtained. Significantly increased levels were observed in patients with malignant liver lesions (hepatocellular carcinoma, lymphoma, metastases). If their levels were increased during benign processes, they were within the limits. It should be noted that two patients were diagnosed with a primary malignant liver tumor on the basis of ultrasound and were prescribed additional radiological research methods (X-ray computed tomography with contrast and magnetic resonance imaging). But  the detected changes in the liver using these methods neither confirmed nor refuted the previous ultrasound diagnosis. Scintigraphic changes in the liver also only indicated its focal lesion. But after determining the tumor markers, it was found that their levels were not just within the limit values, but not elevated at all. Upon further thorough examination of these patients by other laboratory methods, the diagnosis of primary liver tumor was canceled.

Conclusions. Thus, after ultrasound of the liver, if focal changes in the parenchyma were detected with suspicion of a malignant neoplasm, further appointment of X-ray computed tomography and magnetic resonance imaging is not appropriate. It will be more informative to determine the tumor markers of alpha-fetoprotein, cancer-embryonic antigen, specific antigen 19-9, beta-2 microglobulin and thymidine kinase, which are the main ones in malignant liver lesions (primary and secondary). The analysis method itself (radioimmunological or immunoenzymatic) does not affect the results of the values. If their levels are significantly increased, then the liver damage has a malignant nature, if they are within the normal or limit values, then the process is benign or of an inflammatory origin.

Keywords: static hepatoscintigraphy, focal lesions, liver lymphoma, hepatocellular carcinoma, liver metastases, liver hemangioma, focal nodular hyperplasia of the liver, radioimmunological analysis, tumor markers, alpha-fetoprotein, cancer-embryonic antigen, specific antigen 19-9, beta-2 microglobulin, thymidine kinase.