Technetium-99m-ubiquicidin 29-41 SPECT-CT to detect postsurgical spinal infection: A case report

Abstract

Background: Postsurgical spinal infections are a severe complication and a challenge to the neurosurgeon due to their complex management. Revision surgeries and the removal of hardware are usually necessary. Recently, advances in nuclear medicine have made it possible to employ radiotracers to identify infections. The radiolabeled antimicrobial peptide technetium-99m-ubiquicidin (99mTc-UBI) (29-41) has been demonstrated to detect bacterial infections. UBI 29-41 is a peptide sequence with selective binding to the anionic cell membrane of bacteria, which has recently been used to differentiate between infection and inflammation. Here, we describe the clinical utility of 99mTc-UBI 29-41 single-photon emission computed tomography-computed tomography (SPECT-CT) in a patient suspected of a postoperative infection.

Case description: A 54-year-old male who presented with conus medullaris syndrome secondary to T12 spondylodiscitis and multiple abscess collections was initially managed with debridement, corpectomy, and minimally invasive lateral instrumentation. The patient developed postsurgical empyema near the surgical site. The image study avoided the need for a second surgery and hardware removal.

Conclusion: The use of 99mTc-UBI 29-41 SPECT-CT served as a tool to avoid a second invasive procedure; instead, conservative management with antibiotics was performed with an effective outcome after two weeks. This radiotracer has utility in cases in which infection is suspected, but the location is not entirely clear, and information is needed to guide the therapeutic approach.

Keywords: Nuclear medicine; Postsurgical infection; Single-photon emission computed tomography; Spinal infection; Ubiquicidin.

Figure 1:

Due to the proximity of the empyema to the neurosurgical site, a technetium-99m-ubiquicidin (99mTc-UBI) 29–41 single-photon emission computed tomography-computed tomography (SPECT-CT) was performed to rule out infection of the hardware. As suggested by the 4-point scale for uptake of 99mTc-UBI 29–41 at the site of suspected infection (0 = no uptake; 1 = uptake < liver; 2 = uptake > liver; 3 = uptake > kidneys), uptake was classified as 1 point in the hardware area and 2 points in the suspected infection zone. The study reported an infection in the spinal column at T11-L1 that did not compromise the neurosurgical instrumentation. (a) T11 axial CT (b) with uptake of 99mTc-UBI 29–41. (c and d) Uptake of the suspected site of infection compared with kidney uptake in a coronal and sagittal spine 99mTcUBI 29–41 SPECT-CT.