18F-florbetapir PET/MRI for quantitatively monitoring myelin loss and recovery in patients with multiple sclerosis: A longitudinal study

Min Zhang; You Ni; Qinming Zhou; Lu He; Huanyu Meng; Yining Gao; Xinyun Huang; Hongping Meng; Peihan Li; Meidi Chen; Danni Wang; Jingyi Hu; Qiu Huang; Yao Li; Fabien Chauveau; Biao Li; Sheng Chen

doi:10.1016/j.eclinm.2021.100982

¹⁸F-florbetapir PET/MRI for quantitatively monitoring myelin loss and recovery in patients with multiple sclerosis: A longitudinal study

EClinicalMedicine. 2021 Jun 23:37:100982. doi: 10.1016/j.eclinm.2021.100982. eCollection 2021 Jul.

Authors

Min Zhang¹, You Ni², Qinming Zhou², Lu He², Huanyu Meng², Yining Gao², Xinyun Huang¹, Hongping Meng¹, Peihan Li³, Meidi Chen³, Danni Wang⁴, Jingyi Hu⁴, Qiu Huang^{1

3}, Yao Li^{1

4}, Fabien Chauveau⁵, Biao Li¹, Sheng Chen²

Affiliations

¹ Department of Nuclear Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
² Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai 200025, China.
³ School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
⁴ Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
⁵ Univ Lyon, Lyon Neuroscience research Center, CNRS UMR5292, INSERM U1028, Univ Lyon 1, Lyon, France.

Abstract

Background: Amyloid positron emission tomography (PET) can measure in-vivo demyelination in patients with multiple sclerosis (MS). However, the value of ¹⁸F-labeled amyloid PET tracer, ¹⁸F-florbetapir in the longitudinal study for monitoring myelin loss and recovery has not been confirmed.

Methods: From March 2019 to September 2020, twenty-three patients with MS and nine healthy controls (HCs) underwent a hybrid PET/MRI at baseline and expanded disability status scale (EDSS) assessment, and eight of 23 patients further underwent follow-up PET/MRI. The distribution volume ratio (DVR) and standard uptake value ratio (SUVR) of ¹⁸F-florbetapir in damaged white matter (DWM) and normal-appearance white matter (NAWM) were obtained from dynamic and static PET acquisition. Diffusion tensor imaging-derived parameters were also calculated. Data were expressed as mean ± standard deviation with 99% confidence interval (99%CI).

Finding: The mean DVR (1.08 ± 0.12, 99%CI [1.02 ~ 1.14]) but not the mean SUVR of DWM lesions was lower than that of NAWM in patients with MS (1.25 ± 0.10, 99%CI [1.20 ~ 1.31]) and HCs (1.29 ± 0.08, 99%CI [1.23 ~ 1.36]). A trend toward lower mean fractional anisotropy (374.95 ± 45.30 vs. 419.07 ± 4.83) and higher mean radial diffusivity (0.45 ± 0.05 vs. 0.40 ± 0.01) of NAWM in patients with MS than those in HCs was found. DVR decreased in DWM lesions with higher MD (rho = -0.261, 99%CI [-0.362 ~ -0.144]), higher AD (rho = -0.200, 99%CI [-0.318 ~ -0.070]) and higher RD (rho = -0.198, 99%CI [-0.313 ~ -0.075]). Patients' EDSS scores were reduced (B = 0.04, 99%CI [-0.005 ~ 0.084]) with decreased index of global demyelination in the longitudinal study.

Interpretation: Our exploratory study suggests that dynamic ¹⁸F-florbetapir PET/MRI may be a very promising tool for quantitatively monitoring myelin loss and recovery in patients with MS.

Funding: Shanghai Pujiang Program, Shanghai Municipal Key Clinical Specialty, Shanghai Shuguang Plan Project, Shanghai Health and Family Planning Commission Research Project, Clinical Research Plan of SHDC, French-Chinese program "Xu Guangqi".

Keywords: 18F-florbetapir; Demyelination; Multiple sclerosis; Myelin loss and recovery; PET/MRI.