Assessment of different regions of interest-based methods for [99mTc]Tc DAT-SPECT quantification using an anthropomorphic striatal phantom

Author(s)

Alexandre-Santos, Leonardo ; Trevisan, Ana Carolina ; Pitella, Felipe Arriva ; Tumas, Vitor ; Silvah, Jose Henrique ; Kato, Mery ; de Moraes, Eder Rezende ; Wichert-Ana, Lauro

• Document type: Journal article
• Source: EJNMMI PHYSICS; v. 9, n. 1, p. 14-pg., 2022-12-28.

Abstract

Background and aims: Molecular imaging of the dopamine transporters (DAT) pro-vides valuable information about neurodegenerative diseases, such as Parkinson's. This study assessed the accuracy and precision of DAT-SPECT quantification methods. Methods: Twenty-three DAT-SPECT images of a striatal phantom were acquired. The specific (caudate and putamen) and the non-specific (background activity) chambers were filled with [(99mTc)]Tc. Different specific-to-non-specific activity ratios (10, 9, 8, 7, 6, 5, 4, 3 and 2 to 1) and the specific binding ratio (SBR) were calculated. Five methods using ROIs were assessed: (a) Manual ROIs on SPECT images; (b) TwoBox and (c) Three-Box methods and Volume of Interest (VOI) using structural images; (d) MRI and (e) CT. Accuracy was evaluated by the concordance correlation coefficient (CCC) and precision by Pearson's coefficient and linear regression. Results: The SBR quantified in the specific and striatal chambers resulted in a CCC increase with a decrease in the nominal values. For lower SBR, MRI and CT showed higher CCCs when caudate ( CCCMRI-CA = 0.89 e CCCCT-CA = 0.84) and putamen ( CCCMRI-PU = 0.86 e CCCCT-PU = 0.82) were evaluated. For striatal assessments, the Two Box method was the most accurate (CCCTWOBOX-ST = 0.95). High Pearson's coefficients were found in the correlations between all methods. conclusions: All five methods showed high precision even when applied to images with different activities. MRI and CT were the most accurate for assessing the caudate or putamen. To assess the striatal chamber and in the absence of structural information, the Two Box method is advisable. (AU)

• FAPESP's process: 13/25987-2 - Evaluation of the density of presynaptic dopamine Tranporters in humans: development and evaluation of quantitation protocols based on the hybrid SPECT-CT technology using 99mTc-TRODAT-1
• Grantee: Lauro Wichert Ana
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/12671-3 - Correlation between the cerebral metabolic rate of glucose on PET/CT with [18F]FDG and clinical, neurocognitive and therapeutic variables after COVID-19
• Grantee: Lauro Wichert Ana
• Support Opportunities: Regular Research Grants