Avaliação quantitativa e qualitativa da densidade de transportadores pré-sinápticos de Dopamina em pacientes saudáveis e em portadores de Doença de Parkinson: um estudo de SPECT com [99mTc]-TRODAT-1

Abstract

accurate was the manual, followed by Two Box. The manual method would potentially reduce false positive cases from 3 to 0 and false negative cases from 9 to 7. The reproducibility of semiquantitative methods was excellent. In general, negative correlations between striatal DAT binding and PD severity and motor scales were found, however, the correlations were not statistically significant. Asymmetry index and putamen/caudate ratio presented inferior performance compared to BPI. A statistically significant difference between the group with dyskinesia and without dyskinesia in the striatum and caudate BPI was found. Conclusion: Qualitative evaluation of DAT-SPECT with TRODAT-1 presents excellent differential diagnosis performance among healthy and PD patients. Semiquantitative evaluation is complementary to the qualitative evaluation, and may contribute in a way to reduce false negatives or false positives.

Evaluation of Brain SPECT with 99mTc-TRODAT-1 in the Differential Diagnosis of Parkinsonism

“…These results were similar to those found by Pagano et al [ 13 ] with 61.6 ± 9.7 for PD and by Tzen et al [ 15 ] with 70 ± 7.5 for VP. We believe that these differences in age and gender between the Parkinsonism did not influence the differences obtained in the SPECT-TRODAT results because most studies with PET-CT and SPECT have not shown statistically significant differences between changes in DAT uptake concerning sex [ 13 , 14 , 28 – 32 ]. Moreover, DAT/SPECT uptake rates in healthy patients are stable between 30 and 70 years of age, allowing someone around 70 years of age to have SPECT-TRODAT results similar to another 30-year old [ 14 ].…”

“…Seeking an earlier diagnosis, preferably in the premotor phase of PD, the valorization of NMS as clinical biomarkers is occurring, especially in conjunction with imaging, genetic, or biochemical biomarkers [ 1 , 29 ]. The ease in analyzing the images obtained by SPECT-TRODAT, by visual inspection, allows a well-trained neurologist to correlate them with the neurological examination findings [ 8 , 9 , 11 , 14 ].…”

“…NMS in PD and other forms of Parkinsonism is considered critical clinical biomarkers. We found some studies correlating SPECT-TRODAT with the presence of NMS [ 10 , 13 , 14 , 17 , 30 , 33 , 35 ]. Rizzo and Plazzi [ 35 ] observed a high incidence of reduced DAT uptake in patients with RSBD, suggesting that these patients should be followed longitudinally to check for conversion to PD.…”

“…Imaging with DAT/SPECT is increasingly present in evaluations of neurological patients functioning as highly specific and reliable imaging biomarkers in diagnosing and following neurodegenerative diseases, including PD, other SNPs, VP, and DIP [7][8][9][10][11][12][13][14][15][28][29][30][31][32][33][34][35]. Seeking an earlier diagnosis, preferably in the premotor phase of PD, the valorization of NMS as clinical biomarkers is occurring, especially in conjunction with imaging, genetic, or biochemical biomarkers [1,29].…”

“…However, imaging tests and other markers may be essential tools for a quick and correct diagnosis. Since the 80s, with the emergence of PET (positron emission tomography) and SPECT (single-photon emission tomography) functional radiotracers, it became possible to analyze the integrity of dopaminergic systems in vivo, which has helped in the differential diagnosis between PD and other Parkinsonism [8][9][10][11][12][13][14][15].…”