PROSPECTIVE-STUDY OF BONE, INDIUM-111-LABELED WHITE BLOOD-CELL GA-67 SCANNING FOR THE EVALUATION OF OSTEOMYELITIS IN THE DIABETIC FOOT

Twenty-two adult diabetic patients with clinical suspicion of foot and /or ankle infection were prospectively evaluated using radiography, te chnetium-99m methylene diphosphonate bone scanning (Tc-99m), indium-11 1-labeled leukocyte scanning (In-111), and gallium-67 scanning (Ga-67) to determine the presence of clinically suspected osteomyelitis, Biop sy for culture and histology was performed in 16 patients. The diagnos is of osteomyelitis was confirmed by biopsy in 12 patients, The remain ing 10 patients had no evidence of osteomyelitis with long-term follow -up, Tc-99m was shown to be of limited valued when used alone in these patients with peripheral neuropathy, Ga-67, either alone or in combin ation with Tc-99m bone scanning, was of little diagnostic value and ga ve no additional information that was not available from In-111, The c ombination of three-phase Tc-99m and In-111 had the highest diagnostic efficacy (100% sensitivity, 80% specificity, and 91% accuracy), follo wed closely by In-111 alone (100% sensitivity, 70% specificity, and 86 % accuracy). We conclude that for adult diabetic patients with clinica l suspicion of osteomyelitis but no radiographic findings of that dise ase, In-111 alone is an appropriate nuclear medicine evaluation for ru ling out infection if it is negative, However, if an area of In-111 wh ite blood cell uptake is present, a ''simultaneous'' Tc-99m is often h elpful in providing the anatomic correlation to differentiate osteomye litis from infection that is limited to soft tissue.