99mTc leukocyte SPECT/CT for diagnosis of left ventricular assist device (LVAD) infection

Objectives LVAD is a therapeutic option for end-stage heart failure, implanted below the diaphragm, connected by a percutaneous electric cable through the skin to external batteries. Device-related infection are frequent with difficult and challenging diagnosis and treatment. We have evaluated ^99mTc-leukocyte SPECT/CT for the diagnosis and the monitoring of infection in LVAD patients.

Methods 11 planar and SPECT/CT scans were performed in 7 LVAD patients to assess: suspected device-related infection (n=2), extent of known infection (n=5), or efficiency of current antibiotic therapy (n=4). Scans were acquired on a SymbiaT2 , 4 and 24 hours after reinjection of ^99mTc-leukocytes labeled. Planar scans, reconstructed corrected and non corrected SPECT/CT were analyzed, looking for abnormal uptake foci.

Results Acquisition quality was sufficient in all cases despites device related artifacts. Abnormalities were identified in 6/11 planar scans but it was not possible to localize infectious sites. SPECT/CT revealed its exact localization and extension in all cases. Clinical and/or bacteriological evolution was concordant with SPECT/CT findings in all cases.

Conclusions ^99mTc-leukocyte SPECT/CT is feasible with an image quality suitable for analysis in LVAD patients. SPECT/CT allows an accurate diagnosis and reveals the exact extension of LVAD-related infection. This new non invasive approach could help for a better management of infection and should be considered when infection is suspected.