Objective:

To evaluate the role of a 99mTc-antigranulocyte Fab’ fragments (LeukoScan), the diagnosis of brucellar spondylitis. This radiotracer, tank to its capacity to accumulate in the infectious foci, has been used successfully in the diagnosis of orthopaedic infections.

Patients and methods:

A total of 36 consecutive patients (mean age 52.3; SD 18) with brucellosis were enrolled; of these those with suspected spondylitis underwent Leukoscan and MRI. Leukoscan study was performed 4 and 24 h after the administration of 555 MBq of the radiotracer with dual headed gamma-camera equipped with low energy high resolution collimator. Planar and SPET images of the regional interest were acquired. Leukoscan images were interpreted as positive when uptake in the region of interest exceeds uptake in some reference point and also in presence of photopenia as demonstrated by Palestro. Sensitivity and specificity of Leukoscan were computed taking MRI as ‘gold standard’.

Results:

A total of 22 with suspected spondylitis underwent MRI and Leukoscan. MRI detected a skeleton involvement in 11/22 cases and showed still other alterations: nine paraspinal abscess, four a psoas abscess and 10 epidural extension of disease. Leucoscintigraphy of the 11 patients positive to MRI demonstrated normal vertebral activity in seven cases, increased in two and decreased in two. One of the two patients with antigranulocyte increased uptake was not correspondence with the skeleton involvement demonstrated by MRI. Leukoscintigraphy of the 11 patients negative MRI demonstrated increased activity in two cases and in none a decreased one.

Considering both hyperactivity and hypoactivity, Leukoscan sensitivity and specificity were 27.2 and 81.1%, respectively; negative predictive value and positive predictive value were 52 and 60%, respectively.

Conclusion:

Contrary to what we had been longing, Leukoscan was not useful, so we do not recommend its use in the managing of patients with suspected brucellar spondylitis.