Clinical Impact of ¹²³I-Ioflupane SPECT (DaTscan) in a Movement Disorder Center

Abstract

Background/Aims: The clinical diagnosis of degenerative forms of parkinsonism is imperfect, with past studies reporting a high rate of misdiagnosis by neurologists and movement disorder specialists, particularly early in the disease course. ¹²³I-ioflupane SPECT (DaTscan) is a diagnostic neuroimaging tool used to distinguish essential tremor from tremor due to degenerative parkinsonisms. The present study expands upon prior studies of the clinical impact of DaTscan imaging in movement disorder centers by assessing quantitative estimates of diagnostic certainty, the impact on subsequent clinical decisions, and the degree to which the asymmetry in the results corresponds to laterality by clinical history and examination. Methods: In a prospective, observational study of the impact of DaTscan imaging in a movement disorder center over the course of 18 months, 4 specialists completed a questionnaire at the time they ordered imaging and again within 1 month after imaging. Results: Twenty-seven patients underwent DaTscan imaging; the result was normal in 4 cases (14.8%), abnormal in 22 cases (81.4%), and equivocal in 1 case (3.7%). In all cases of a normal result, the post-scan-predicted chance of degenerative parkinsonism decreased compared to the pre-scan prediction (p < 0.05), and in all cases of abnormal scan, the post-scan chance of degenerative parkinsonism increased or remained high (p < 0.0001). Clinical impacts were observed following imaging in a total of 24 patients (88.9%), including changes in medications for 18 patients and psychological impacts for 11 patients. Asymmetric clinical symptoms were corroborated based on the expected asymmetry of dopamine uptake deficits in 57.1% of the cases, were not present in 23.8%, and were opposite of expectations in 19.0% of the scans. Conclusion: DaTscan imaging results have an impact on physician's confidence in the diagnosis of parkinsonism and may also have a psychological impact on patients. DaTscan imaging may be a useful adjunct to clinical history and examination in selected patients.

Impact of DaTscan Imaging on Clinical Decision Making in Clinically Uncertain Parkinson’s Disease

“…Our experience is the largest series reported to date of the use of DaTscan imaging in routine clinical practice. Our results are consistent with prior, smaller, single center reports [8][9][10][11][12][13] that highlight common clinical scenarios where identification of NSDD can help to clarify clinical diagnosis and treatment decisions [6]. In general, an abnormal DaTscan predicted a treatment change when NSDD was uncertain, and a normal DaTscan predicted a change in diagnosis.…”

Clinical utility of DaTscan in patients with suspected Parkinsonian syndrome: a systematic review and meta-analysis

“…ET (18), PD vs. DIP (18), PD vs. VP (12), PD vs. normal variant (11), Multifactorial gait D/o (7), Patient requested (4), uncertain PD (3), Unusual tremor (2), Known Dx of MS (2), Myelopathic signs (2), Dystonic features (1), Myoclonus (1), Psychogenic (1), Young-onset with atypical features (1) Bhattacharjee et al 10 256 UK Retrospective, single-arm 71.65 ± 16.02 53% NR modified H&Y/UK PD Brain Bank Visual and semi-quantitative 4.35 PD (190), VP (5), ET (18), DIP (8), Other (8) LBD (22), Diagnosis Uncertain (5) Crotty et al 11 261 Ireland Retrospective, single-arm 65.6 ± 12.22 57% NR NR NR NR PS (163), LBD (7), DIP (45), PD vs. ET (12), PD vs. dementia (2), PS vs. PD (19), PD progression (2), PD vs. VP (8), PD vs. dystonia (2), unclear (1) Garcia Vicente et al 12 42 Spain Retrospective, single-arm 78.7 (50–88) 38% 12 NR Visual and semi-quantitative NR PD (19), VP (14), ET (5), DIP (2), Other (2) Graebner et al 13 27 USA Prospective, single-arm 61.2 ± 13.4 52% 1 NR NR 4.1 DP vs. ET (5), DP vs. VP (4), DP vs. DIP (4), DP vs. psychogenic or malingering (3), DP vs. others (6), Patient request (4) Hesse et al 14 278 Germany Retrospective, single-arm 63 ± 12 59% 18 UK PD Brain Bank/MDS-PD/PSP criteria NR 4.25 PD (129), MSA (10), PSP (8), VP (15), SWEDD (116) Jennings et al 15 35 USA Retrospective, single-arm 66.8 (46.2–81.7) 63% 6 NR Quantitative 2.4 ...…”

“…The primary endpoints were the pooled analysis of the proportions of patients who had a change in management and in diagnosis following imaging with DaTscan. Change in management was reported by 13 studies 6 , 7 , 9 – 12 , 18 , 20 , 21 , 23 – 25 including 950 patients. Using a random-effects model 54% (95% CI: 47–61%) of patients had a change in management following the scan (Fig.…”

Automatic Analysis of Archimedes’ Spiral for Characterization of Genetic Essential Tremor Based on Shannon’s Entropy and Fractal Dimension

“…The differential diagnosis between PD and ET is clinical. When the diagnosis is doubtful, a SPECT-DAT scan can be performed, which consists in evaluating the striatal uptake of 123I-2b-carbomethoxy-3b-(4-iodophenyl)- N -(3-fluoropropyl)-nortropane using a SPECT (Single Photon Emission Computed Tomography), a test that is extremely expensive, and therefore not easily accessible in habitual clinical practice [ 3 ]. In spite of the usefulness of these biomarkers, the expenses and requirements of the needed technology make it unfeasible to use these tests with every patient that has motor conditions.…”