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Background. The treatment outcomes for non-small cell lung cancer (NSCLC) depend on the tumor stage and treatment strategy. The imaging techniques play a significant role in the diagnosis, staging and choice of appropriate treatment for NSCLC.Purpose of the study: сomparison of the diagnostic capabilities of magnetic resonance imaging (MR) and positron emission computed tomography to select the optimal approaches to early detection of spinal and pelvic bone metastases.Material and Methods. The treatment outcomes were analyzed in 71 patients with NSCLC. Spinal and pelvic bone metastases were detected in 24 patients using magnetic resonance imaging (MRI) and positron emission computed tomography (PET/CT). Multiple bone lesions were the most common. A total of 69 metastatic lesions were identified. To compare the capabilities of diagnostic techniques, all patients underwent PET/CT with 18F-FDG, and MRI of the spine and pelvic bones using diffused-weighted images (DWI). Statistical data processing included the calculation of the sensitivity, specificity and diagnostic accuracy of the above techniques.Conclusion. The comparative analysis of the capabilities of modern high-tech diagnostic techniques (PET/CT with 18F-FDG and MRI of the spine and pelvic bones with DWI) in early detection of bone metastases in patients with NSCLC, PET/CT with 18F-FDG showed the greatest diagnostic value. However, taking into account the high sensitivity and specificity of MRI with DVI in detection of bone metastases and limited availability of PET/CT for patients, MRI with DVI is recommended to exclude bone metastases.

The aim of the investigation was to estimate the sensitivity of combined positron emission and computed tomography (PET/CT) in the diagnostics, extension and treatment efficiency of neuroendocrine tumors (NET) using 68Ga-DOTA-TATE as an imaging agent. Materials and Methods. PET/CT with 68Ga-DOTA-TATE was performed in 86 patients with pulmonary and gastrointestinal NET (55 patients underwent it preoperatively, 31 patients — postoperatively). All patients before PET/СТ were administered a diagnostic dose of radiopharmaceutical (RP) at the rate of 1.5 MBq per a kilogram of body mass but not less than 100 MBq. The developed RP synthesis module (Gerat13–68Ga) enabled to prepare a ready for intravenous administration 68Ga-DOTA-TATE within 15 min. Moreover, RP was defined to have a stably high radiochemical yield (over 50% without decay correction) and the appropriate quality. The patients were scanned 50–60 min after RP injection, the procedure being carried out according to a whole body protocol using PET/CT Discovery 690 (General Electric, USA). The data processing included the image analysis of computed and positron emission tomograms, as well as combined images. The main feature of sst-positive tissue tumor was pathological focal 68Ga-DOTA-TATE hyperfixation even if there were no evident structural changes of the organ according to CT findings. In cases when CT showed a tumor but the tumor didn't accumulated RP, its nature was considered to be malignant and the tumor was estimated as sst-negative. Results. In patients examined before treatment, the sensitivity of PET/CT with 68Ga-DOTA-TATE to diagnose a primary tumor was 90.9% (50/55). In 3 patients PET showed a sst-negative tumor, in 2 patients a primary mass was not detected after tomography either. In addition, an initially determined stage of the disease was confirmed by PET/CT in 36 of 47 cases (76.6%). The rest patients were found to have second metastases in different organs and systems. PET/CT findings in 13 of 31 patients examined after the treatment didn't coincide with those obtained by other techniques. In 6 patients the presence of pathological PR accumulation indicated no positive effect of the therapy, 3 patients were found to have secondary changes, 3 patients were detected to have a significant increase of liver metastases (only in CT), and 1 female patient after surgery appeared to have the disease recurrence in the stump of the left main bronchus. Conclusion. PET/CT with 68Ga-DOTA-TATE demonstrated high efficiency in primary tumor detection, the assessment of therapy results and NET extension.