The gallium scan: problems and misuse in examination of patients with suspected infection

Gallium citrate Ga 67 (67Ga) has been used for almost ten years as a means of detecting inflammatory lesions in febrile patients. We have reviewed 80 cases from Milwaukee County General Hospital (1977 through 1979) in which 67Ga scanning was performed to detect inflammatory lesions in patients by suspected infection. Fifty scans also were available for review by the nuclear medicine staff. We found the sensitivity of 67Ga scans at our institution to be 90%, but specificity to be only 64%. In five (6%) of the cases, 67Ga scanning was the most important means of establishing a diagnosis. Of the 50 scans available for review, only 26 scans (52%) were interpreted in the same way as the original reading. Twenty-two (27%) of all scans in retrospect should not have been ordered, either because of the fever was gone and the patient's condition was improving or the diagnosis was already made. We conclude that 67Ga scans can be useful to detect inflammatory lesions but that they are frequently used inappropriately by physicians at our hospital, they are difficult to interpret, and the specificity is lower than the sensitivity.