Appropriate reference region selection of 18F-florbetaben and 18F-flutemetamol beta-amyloid PET expressed in Centiloid
Soo Hyun Cho, Yeong Sim Choe, Seongbeom Park, Young Ju Kim, Hee Jin Kim, Hyemin Jang, Seung Joo Kim, Jun Pyo Kim, Young Hee Jung, Byeong C. Kim, Duk L. Na, Seung Hwan Moon, Sang Won Seo
Abstract
Abstract The Centiloid (CL) is a method for standardizing amyloid beta (Aβ) quantification through different ligands and methods. To find the most appropriate reference region to reduce the variance in the Aβ CL unit between 18 F-florbetaben (FBB) and 18 F-flutemetamol (FMM), we conducted head-to-head comparisons from 56 participants using the direct comparison of FBB-FMM CL (dcCL) method with four reference regions: cerebellar gray (CG), whole cerebellum (WC), WC with brainstem (WC + B), and pons. The FBB and FMM dcCL units were highly correlated in four reference regions: WC (R 2 = 0.97), WC + B (R 2 = 0.98), CG (R 2 = 0.92), and pons (R 2 = 0.98). WC showed the largest effect size in both FBB and FMM. Comparison of the variance of the dcCL values within the young control group showed that with FBB, WC + B had the smallest variance and with FMM, the WC had the smallest variance. Additionally, WC + B showed the smallest absolute difference between FBB and FMM, followed by the WC, pons, and CG. We found that it would be reasonable to use the WC or WC + B as the reference region when converting FBB and FMM SUVRs into dcCL, which can increase the accuracy of standardizing FBB and FMM PET results.