Prospective Study of Bone, lndium-111-Labeled White Blood Cell, and Gallium-67 Scanning for the Evaluation of Osteomyelitis in the Diabetic Foot

TLDR

Twenty‑two diabetic patients suspected of foot/ankle infection were prospectively evaluated with radiography, 99Tc bone scan, 111In leukocyte scan, and 67Ga scan, and biopsy was performed in 16 cases. Biopsy confirmed osteomyelitis in 12 of 22 patients; 99mTc alone was of limited value, 67Ga alone or with 99mTc added little information, while the combination of 99mTc and 111In achieved 100 % sensitivity, 80 % specificity, and 91 % accuracy, and 111In alone was sufficient to rule out infection when negative, with 99mTc added only when 111In uptake was present.

Abstract

Twenty-two adult diabetic patients with clinical suspicion of foot and/or ankle infection were prospectively evaluated using radiography, technetium-99m methylene diphosphonate bone scanning ( 99 Tc), indium-111-labeled leukocyte scanning ( 111 In), and gallium-67 scanning ( 67 Ga) to determine the presence of clinically suspected osteomyelitis. Biopsy for culture and histology was performed in 16 patients. The diagnosis of osteomyelitis was confirmed by biopsy in 12 patients. The remaining 10 patients had no evidence of osteomyelitis with long-term follow-up. 99m Tc was snown to be of limited valued when used alone in these patients with peripheral neuropathy. 67 Ga, either alone or in combination with 99m Tc bone scanning, was of little diagnostic value and gave no additional information that was not available from 111 In. The combination of three-phase 99m Tc and 111 In had the highest diagnostic efficacy (100% sensitivity, 80% specificity, and 91% accuracy), followed closely by 111 In alone (100% sensitivity, 70% specificity, and 86% accuracy). We conclude that for adult diabetic patients with clinical suspicion of osteomyelitis but no radiographic findings of that disease, 111 In alone is an appropriate nuclear medicine evaluation for ruling out infection if it is negative. However, if an area of 111 In white blood cell uptake is present, a “simultaneous” 99m Tc is often helpful in providing the anatomic correlation to differentiate osteomyelitis from infection that is limited to soft tissue.