<sup>199</sup>Tl-CHLORIDE SCINTIGRAPHY: DIFFERENT TYPES OF VISUALIZATION OF MUSCULOSKELETAL MALIGNANT TUMORS
Introduction. 199Tl-chloride scintigraphy is used to visualize tumors. In addition to typical imaging of the musculoskeletal malignancy, unusually types of malignant tumor visualization were revealed by studies of diagnostic potentialities of 199Tl-chloride scintigraphy, analogue of 201Tl-chloride scintigraphy. Aim. Was to study features of malignant tumor visualization of the musculoskeletal system with the help of 199Tl-chloride scintigraphy. Materials and methods. 85 patients with diseases of musculoskeletal system underwent 199Tl-chloride scintigraphy. 107 localizations of malignant tumors (n=57) and benign lesion (n=50) were investigated. During the research in 107 patients malignant tumors were detected, 50 patients had bening tumors. Results. Malignant tumors were visualized in 98.1%. Three types of malignant tumors' visualization were obtained - positive (82.4%) and rare negative (7.8%) and mixed (9.8%). Types of visualization were associated with tumor histological types, blood-flow, metabolism, and pharmacodynamic features of 199Tl-chloride. Negative and mixed visual types were high specific for primary and recurrent malignant tumors, but no metastasis. Conclusion. Accounting to negative and mixed visual types - 199Tl-chloride scintigraphy sensitivity increased to 98.1% without decreasing of specificity in detection of malignant tumors of musculoskeletal system.