<sup>199</sup>Tl-CHLORIDE SCINTIGRAPHY: DIFFERENT TYPES OF VISUALIZATION OF MUSCULOSKELETAL MALIGNANT TUMORS
Introduction. <sup>199</sup>Tl-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 <sup>199</sup>Tl-chloride scintigraphy, analogue of <sup>201</sup>Tl-chloride scintigraphy. Aim. Was to study features of malignant tumor visualization of the musculoskeletal system with the help of <sup>199</sup>Tl-chloride scintigraphy. Materials and methods. 85 patients with diseases of musculoskeletal system underwent <sup>199</sup>Tl-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 <sup>199</sup>Tl-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 - <sup>199</sup>Tl-chloride scintigraphy sensitivity increased to 98.1% without decreasing of specificity in detection of malignant tumors of musculoskeletal system.