Radionuclide Diagnosis of Sentinel Lymph Nodes in Breast cancer with a Radiopharmaceutical Based on Technetium-99m Labeled Gamma Aluminum Oxide

Аim: To analyze the results of radionuclide diagnostics of sentinel lymph nodes (SLN) in patients with breast cancer (BC) with the radiotracer Sentiscan, 99mTc (manufacturer “MedicorPharma-Ural”) using the multimodal SPECT/CT at the stage of visualization. Material and methods: The study was retrospective, it included 48 patients with BC with clinical stage T2-3N0M0, who underwent radionuclide diagnostics of SLN and SPECT/CT was performed at the imaging stage. The images were evaluated visually, the intensity of the radiotracer accumulation in the lymph nodes (LN) was analyzed, SUVmax was used as a quantitative parameter. Intraoperative detection of SLN with subsequent histological examination was also carried out with the calculation of the level of the radiotracer accumulation. Results: On tomoscintigrams, LNs were visualized in 43 patients out of 48, intraoperatively ‒ in 46 cases, in 2 patients, accumulation of the radiotracer in the LN projection was noted neither according to SPECT/CT, nor intraoperatively. When analyzing the intensity of the radiotracer accumulation according to SPECT/CT data, a rather large scatter of SUVmax‒35 [10‒104]. Sentinel were considered LNs with the level of the radiotracer accumulation in them of at least 10 % of the most intense node. According to SPECT/CT data, 165 lymph nodes were identified, the average number of lymph nodes detected in one patient was 2 [1‒3], the maximum number was 6 lymph nodes. In all patients, the lymph nodes were determined in the projection of the 1st level, in 25 cases ‒ in the projection of other zones of regional lymphatic outflow. The total number of lymph nodes removed during surgery was n=247, on average 3 [2‒5] lymph nodes were removed in one patient, with a maximum of 8 nodes. Conclusion: The sensitivity of radionuclide diagnostics of SLN with Sentiscan, 99mTc was 89.6 % according to SPECT/CT and 95.8 % according to the results of intraoperative detection. The use of multimodal imaging provides information on the exact anatomical localization of the lymph nodes. In the absence of scintigraphic visualization of the radiotracer redistribution in the lymphatic collector, intraoperative detection does not lose its relevance.