We assessed the clinical utility of indium 111–labeled white blood cell scans at our tertiary referral center from 2005 to 2011. Overall, scans meaningfully impacted clinical care <50% of the time. Scan utility was greater for suspected vascular graft infections or osteomyelitis.
We sought to characterize the clinical utility of indium 111 ( 111In)–labeled white blood cell (WBC) scans by indication, to identify patient populations who might benefit most from this imaging modality.
Medical records for all patients who underwent 111In-labeled WBC scans at our tertiary referral center from 2005 to 2011 were reviewed. Scan indication, results, and final diagnosis were assessed independently by 2 infectious disease physicians. Reviewers also categorized the clinical utility of each scan as helpful vs not helpful with diagnosis and/or management according to prespecified criteria. Cases for which clinical utility could not be determined were excluded from the utility assessment.
One hundred thirty-seven scans were included in this analysis; clinical utility could be determined in 132 (96%) cases. The annual number of scans decreased throughout the study period, from 26 in 2005 to 13 in 2011. Forty-one (30%) scans were positive, and 85 (62%) patients were ultimately determined to have an infection. Of the evaluable scans, 63 (48%) scans were deemed clinically useful. Clinical utility varied by scan indication: 111In-labeled WBC scans were more helpful for indications of osteomyelitis (35/50, 70% useful) or vascular access infection (10/15, 67% useful), and less helpful for evaluation of fever of unknown origin (12/35, 34% useful).