Comparison of Tc-99m-labelled antileukocyte fragment Fab' and Tc-99m-HMPAOleukocyte scintigraphy in the diagnosis of bone and joint infections: a prospective study

Between January and July 1998, we conducted a prospective study to compare Tc-99m-labelled antigranulocyte monoclonal antibody fragment Fab' (LEUKOSCA N(R)); scintigraphy versus Tc-99m-hexamethylpropyleneamine oxime (Tc-99m-HM PAO)-labelled leukocyte scintigraphy (HMPAO-LS) for the diagnosis of unsele cted patients with bone and joint infection. Twenty-three patients (16 men and 7 women; mean age, 67 years) with suspect ed bone infection were explored successively with bone scintigraphy, HMPAO- LS and LEUKOSCAN(R) scintigraphy. Thirty-two foci were studied (diabetic fo ot = 11, prosthetic material = 8, joint disease = 4, others = diagnosed in 18 cases, eight on the basis of bacteriological and histological examinatio n of surgical or puncture specimens, with or without radiographic signs, an d 10 on the basis of clinical course and radiographic findings. Overall sen sitivity, specificity and accuracy were 86%, 72% and 78%, respectively, for LEUKOSCAN(R) scintigraphy (12 true positives (TP), 13 true negatives (TN), 5 false positives (FP), 2 false negatives (FN)), 93%, 100% and 96%, respec tively, for HMPAO-LS (13TP, 18TN, 0FP, 1FN), and 100%, 17% and 53.3%, respe ctively, for bone scintigraphy. In this small series, LEUKOSCAN(R) scintigraphy was found to be less specif ic for the diagnosis of osteomyelitis than HMPAO-LS. In addition, the inter pretation of LEUKOSCAN(R) scintigraphy is more difficult than HMPAO-LS for the diagnosis of bone infection in the diabetic foot, and would appear to b e less discriminating for differentiating soft tissue infection from osteit is in the case of plantar perforating ulcers. (C) 2000 Lippincott Williams & Wilkins).