The use of 99mTc-DTPA for detection and localization of site of acute gastrointestinal bleeding

Evolving role of radiolabeled particles in detecting infection and inflammation, preliminary data with 99mTc-phytate in rats

PURPOSE

The aim of this study was to evaluate the ability of phytate radiolabeled with technetium-99m (Tc-phytate) to identify inflammatory processes.

MATERIALS AND METHODS

Radiolabeling efficiency analyses were carried out by thin-layer chromatography on silica gel strips, yielding a radiochemical purity of 92%. In addition, the partition coefficient of Tc-phytate, obtained in a mixture of n-octanol/water (1 : 1), showed hydrophilic features of the radiopharmaceutical. After Tc-phytate was administered into the tail vein of healthy and inflammation focus-bearing rats, induced, in the right tight, by zymosan suspension at 5% (w/v), blood clearance evaluation was performed and showed a short plasma half-life (2.7 min). In the inflammation focus-bearing rats, Tc-phytate scintigraphic images were obtained at 2, 4, and 8 h after radiotracer injection.

RESULTS

A significant radiopharmaceutical uptake was found in mononuclear phagocyte system organs (liver and spleen) and in the inflammation focus (compared with contralateral muscle). Histopathological analysis showed an intense mononuclear infiltration in the inflamed muscle, suggesting that macrophages may be responsible for the greater radiotracer uptake in the inflamed site. Furthermore, the target-to-nontarget ratio (%ID/g of inflamed muscle-to-%ID/g of control muscle ratio) obtained by scintigraphic images performed at 2 h after the radiotracer injection was 10.24±3.49, remaining without any significant difference at 4 and 8 h.

CONCLUSION

Inflammation focus was evident in the scintigraphic images from 2 to 8 h after Tc-phytate administration, suggesting that this radiopharmaceutical could be a potential alternative to identify inflamed regions.

Structure and Activities of Nuclear Medicine in Kuwait

The practice of nuclear medicine in Kuwait began in 1965 as a clinic for treating thyroid diseases. The practice developed gradually and until 1981 when the Faculty of Medicine established the Division of Nuclear Medicine in the Department of Radiology, which later became a separate department responsible for establishing and managing the practice in all hospitals of Kuwait. In 1987, a nuclear medicine residency program was begun and it is administered by Kuwait Institute for Medical Specializations originally as a 4-year but currently as a 5-year program. Currently there are 11 departments in the ministry of health hospitals staffed by 49 qualified attending physicians, mostly the diplomats of the Kuwait Institute for Medical Specializations nuclear medicine residency program, 4 academic physicians, 2 radiopharmacists, 2 physicists, and 130 technologists. These departments are equipped with 33 dual-head gamma cameras, 10 SPET/CT, 5 PET/CT, 2 cyclotrons, 1 breast-specific gamma imaging, 1 positron-emitting mammography, 10 thyroid uptake units, 8 technegas machines, 7 PET infusion systems, and 8 treadmills. Activities of nuclear medicine in Kuwait include education and training, clinical service, and research. Education includes nuclear medicine technology program in the Faculty of Allied Health Sciences, the 5-year residency program, medical school teaching distributed among different modules of the integrated curriculum with 14 didactic lecture, and other teaching sessions in nuclear medicine MSc program, which run concurrently with the first part of the residency program. The team of Nuclear Medicine in Kuwait has been active in research and has published more than 300 paper, 11 review articles, 12 book chapters, and 17 books in addition to 36 grants and 2 patents. A PhD program approved by Kuwait University Council would begin in 2016.