Resumen de Indexing Severity of Diabetic Foot Infection With ^sup 99m^Tc-WBC SPECT/CT Hybrid Imaging
Alacoque Lorenzini Erdmann, William A. Erdman, Ji Buethe, Rafia Bhore, Hans K. Ghayee, Chiarra Thompson, Param Maewal, Jon Anderson, Steve Klemow, Orhan K. Oz
Management of diabetic foot infection (DFI) has been hampered by limited means of accurately classifying disease severity. New hybrid nuclear/computed tomography (CT) imaging techniques elucidate a combination of wound infection parameters not previously evaluated as outcome prognosticators. Our aim is to determine if a novel standardized hybrid image-based scoring system, Composite Severity Index (CSI), has prognostic value in DFI. Masked retrospective ^sup 99m^Tc-white blood cell (WBC) single photon emission CT (SPECT)/CT image interpretation and independent chart review of 77 patients (101 feet) suspected of DFI-associated osteomyelitis at a large municipal hospital between January 2007 and July 2009. CSI scores were correlated with probability of favorable outcome (no subsequent amputation/readmission after therapeutic intervention) during median 342-day follow-up. CSI ranged from 0-13. Receiver operating characteristic accuracy for predicting favorable outcome was 0.79 (optimal cutoff CSI, ?2; odds ratio of therapeutic failure for CSI >2, 15.1 [95% CI 4.4-51.5]). CSI of 0 had a 92% chance of favorable outcome, which fell progressively to 25% as indices rose to ?7. Image-based osteomyelitis versus no osteomyelitis assessment was less accurate than CSI at predicting outcome (P = 0.016). In patients with intermediate severity (CSI 3-6), treatment failure decreased from 68 to 36% when antibiotic duration was extended to ?42 days (P = 0.026). ^sup 99m^Tc-WBC SPECT/CT hybrid image-derived wound infection parameters incorporated into a standardized scoring system, CSI, has prognostic value in DFI.
