Relevance of 123I-FP-CIT SPECT prescriptions for the diagnosis of parkinsonian syndromes

Abstract

¹²³I-FP-CIT SPECT enables the detection of presynaptic dopaminergic denervation. It allows to differentiate degenerative parkinsonian syndromes from secondary parkinsonian syndromes or essential tremor, and patients with suspected dementia with Lewy bodies from those with other dementia subtypes. The aim of our study was to evaluate the appropriateness of ¹²³I-FP-CIT SPECT prescriptions, identify prescriber profiles and analyze changes in prescriptions over a decade in the Neurology department of Avicenne University hospital. This retrospective study included all patients who underwent ¹²³I-FP-CIT SPECT between February 2009 and May 2019 (n = 723). Clinical and paraclinical data were compared between three groups based on the relevance of ¹²³I-FP-CIT SPECT prescription: "inappropriate", "uncertain" and "relevant". We showed that inappropriate indications accounted for 37.5% of ¹²³I-FP-CIT SPECT requests. Hospital neurologists and neurologists with mixed practice accounted for 74.1% of ¹²³I-FP-CIT SPECT requests, hospital movement disorders specialists being more likely to prescribe appropriately (67.1%) than hospital non-movement disorders specialists (33.3%). Following the replacement of the neuro-oncology team with a team including movement disorders specialists, the percentage of relevant SPECT 123I-FP-CIT prescriptions rose from 37.5% to 81.0%. These observations suggest that seeking the expertise of a movement disorders specialist would be more relevant than the systematic prescription of ¹²³I-FP-CIT SPECT.

Keywords: 123I-FP-CIT SPECT; Atypical parkinsonian syndromes; Degenerative parkinsonian syndromes; Movement disorders; Parkinson’s disease.

Fig. 1

Distribution of ¹²³I-FP-CIT SPECT prescription relevance according to physicians’ specialty. Relative percentages of prescription relevance were calculated for each physician specialty. Comparisons of relevance distribution among physician specialties were conducting using pairwise Fisher’s exact tests, corrected using Benjamini–Hochberg method. HN: hospital neurologists, MD: movement disorders

Fig. 2

Evolution of the percentages of relevant ¹²³I-FP-CIT SPECT prescriptions and the neurologist mean requests at Avicenne University Hospital from February 2009 to May 2019. Notes. The vertical dotted line indicates the semester when the neuro-oncology team at Avicenne University Hospital was replaced by the new neurology team, which included MD specialists. The percentage of relevant indications was calculated as the number of relevant indications among the total number of requests made by the team in the semester. The neurologist mean requests was calculated as the total number of requests made by the team in the semester divided by the number of neurologists in the team during that semester. The number (n) in parentheses next to the semester on the x-axis represents the number of requests made by the team in the semester.