Diagnostic sensitivity and specificity of the radionuclide (indium)-labeled leukocyte scan.
OBJECTIVE
Evaluate the sensitivity and specificity of Indium(111)-labeled leukocyte scans as used in a general, tertiary care hospital.


METHODS
Retrospective review of electronic medical records from all patients who underwent Indium(111) scan at two large Veterans Affairs Medical Centers, 1999-2005, to determine congruence between Indium(111) scan readings and final clinical diagnoses, using all available data with at least 6 months of follow-up.


RESULTS
Of 145 indium scans done for possible skeletal infection, infection was judged to be present in 52 cases. The sensitivity was 83%, and the specificity was 90%, with a diagnostic accuracy of 88%. Fifty-nine scans were done for indications other than skeletal infection. In 20 instances, when specific foci were suspected, the suspicion was correctly confirmed by indium scan in every case, without false positives or negatives (sensitivity and specificity, 100%). In 39 scans done to search for a possible source of nonspecific findings of infection (fever, leukocytosis, bacteremia), the sensitivity and specificity were 81% and 87%, respectively, with a diagnostic accuracy of 85%.


CONCLUSIONS
Except as a means to confirm an already-suspected clinical focus, the indium scan appears to offer relatively little definitive information that can be used for diagnosis or treatment of infection.
Wanahita
Anna
A
Medical Service (Infectious Disease Section), Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX 77030, USA.
Villeda
Christian
C
Kutka
Nicolas
N
Ramirez
Julio
J
Musher
Daniel
D
D001850:Bone Diseases, Infectious / Q000175:diagnosis*; D005335:Fever of Unknown Origin / Q000175:diagnosis; D006801:Humans; D007205:Indium Radioisotopes; D007962:Leukocytes; D008499:Medical Records; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed / Q000379:methods*
D007205:Indium Radioisotopes