Clinical usefulness of dopamine transporter SPECT imaging with 123I-FP-CIT in patients with possible dementia with Lewy bodies: randomised study.

BACKGROUND Dementia with Lewy bodies (DLB) is underrecognised in clinical settings. AIMS To investigate whether performing a (123)I-ioflupane injection ((123)I-FP-CIT also called DaTSCAN™) single photon emission computed tomography (SPECT) scan in patients with possible DLB would lead to a more certain diagnosis (probable DLB or non-DLB dementia). METHOD We randomised 187 patients with possible DLB 2:1 to have a scan or not (control group). The outcome measure was a change in diagnosis to probable DLB or non-DLB. RESULTS There were 56 controls and 114 scanned patients, of whom 43% had an abnormal scan. More patients in the imaging group had a change in diagnosis compared with controls at 8 and 24 weeks (61% (n = 70) v. 4% (n = 2) and 71% (n = 77) v. 16% (n = 9); both P<0.0001). Clinicians were more likely to change the diagnosis if the scan was abnormal (82%) than if it was normal (46%). CONCLUSIONS Imaging significantly contributed to a more certain diagnosis, proving to be a useful adjunct in the work-up of patients with possible DLB.