Evaluation of 99mTc-labeled antibiotics for infection detection

Abstract

One of the fields of research in nuclear medicine is the development of new radiopharmaceuticals for imaging infection and inflammation in humans. For this development, several antimicrobial peptides, antibiotics, antibiotic peptide and chemotactic peptides, etc., have been radiolabeled with different radionuclides (⁶⁷Ga, ⁹⁹(m)Tc, ¹¹¹In, ¹⁸F, ¹³¹I, etc.) and their imaging potentials studied. Actually, it is very important to distinguish between infection and inflammation. In this respect, radiolabeled antibiotics have advantages because many of the properties of the ideal infection-specific agent through antibiotics localizes in infection site. In this review, only ⁹⁹(m)Tc-labeled antibiotics are evaluated and discussed.

Radiotracers Used for the Scintigraphic Detection of Infection and Inflammation

“…The design of a radiotracer usually depends on the nonradioactive part of the structure to influence its distribution in vivo ( Table 4 )—the cold part is a known participant in an inflammatory step or it interacts with a pathogen directly. Synthetic radiotracers are small molecules that target upregulated antigens, proinflammatory molecules, or receptors at an inflammation, radioactive-antibiotics target microbes [ 28 ], and radiolabeled-biological-molecules target all of these or leukocytes at the lesion site ( Table 5 ). The literature is abundant with reports surrounding their efficacy in small animals, necessary work before clinical application.…”

Molecular Imaging: An Innovative Force in Musculoskeletal Radiology

“…However, the first such agent to be used clinically, 99m Tc-ciprofloxacin, has not shown consistent efficacy in this regard [102,103]. There are numerous more recently developed technetium-labeled antibiotics, which include 99m Tc-alafosfalin and 99m Tc-cefuroxime axetil, many of which show promise but none of which has yet emerged as the desired sensitive and specific imaging agent [104]. Radiolabeling of antibiotics has extended beyond planar imaging to PET, with the development of agents such as N4F18-fluoroalkylated ciprofloxacin [105].…”

The molecular imaging approach to image infections and inflammation by nuclear medicine techniques

“…It is taken up by Gram-positive and Gram-negative bacteria and inhibits DNA synthesis by binding to bacterial DNA gyrase [23], which is present in all dividing bacteria, even to those that are resistant. 99m Tc-ciprofloxacin is mainly excreted via the kidneys; it has low liver metabolism, and bowel uptake is usually very low.…”