99m Tc-Ceftizoxime: Synthesis, characterization and its use in diagnosis of diabetic foot osteomyelitis.

Introduction: The diagnosis of diabetic foot osteomyelitis is crucial and challenging for the proper management of diabetic foot. ^99m Tc labelled Ceftizoxime was used as a non-invasive diagnostic agent for diabetic foot osteomyelitis.
Methods: Ceftizoxime [CFT], a third generation cephalosporin, was used in a simple and direct method for the synthesis of ^99m TcO ₄ ^- labelled infection imaging agent with stannous chloride as reducing agent. Its radiochemical purity was checked by thin Layer chromatography. Partition co-efficient was measured with phosphate buffer and chloroform. The radiochemical complex was injected to control and infected animal model for 3 hours in-vivo localization studied with the help of dual head gamma camera. The labelled complexes were injected to 5 patients of known type II diabetes mellitus suspected of diabetic foot osteomyelitis. All patients underwent dynamic and static ^99m Tc-MDP and ^99m Tc-CFT scans.
Results: The synthesized radio labelled complex was 98.8% pure, with hydrophilic character. When injected to animal model, at 120 minutes, 49.3% was localized in foci of infection with 3.35% in liver and excretion through kidney. Human studies were interpreted as true or false positive and true or false negative based on bone histopathology/culture and clinical follow-up. We found that of 5 patients, 2 were true positive, 2 as true negative with no false positive or negative and 01 patient had soft tissue infection.
Conclusion: This study showed that ^99m Tc-CFT labelled complex could be used for detection of diabetic foot osteomyelitis; however, further confirmation of results with a larger patient population would be optimal.
(© 2018 The Royal Australian and New Zealand College of Radiologists.)