Department of Neurology & Alzheimer Center, Amsterdam Neuroscience, VU University Medical Center, De Boelelaan 1118, 1081 HZ, Amsterdam, The Netherlands.
Alzheimer Operative Unit, IRCCS S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy.
Eur J Nucl Med Mol Imaging. 2018 Jul;45(9):1526-1533. doi: 10.1007/s00259-018-4034-z. Epub 2018 May 9.
A joint effort of the European Association of Nuclear Medicine (EANM) and the European Academy of Neurology (EAN) aims at clinical guidance for the use of FDG-PET in neurodegenerative diseases. This paper addresses the diagnostic utility of FDG-PET over clinical/neuropsychological assessment in the differentiation of the three forms of primary progressive aphasia (PPA).
Seven panelists were appointed by the EANM and EAN and a literature search was performed by using harmonized PICO (Population, Intervention, Comparison, Outcome) question keywords. The studies were screened for eligibility, and data extracted to assess their methodological quality. Critical outcomes were accuracy indices in differentiating different PPA clinical forms. Subsequently Delphi rounds were held with the extracted data and quality assessment to reach a consensus based on both literature and expert opinion.
Critical outcomes for this PICO were available in four of the examined papers. The level of formal evidence supporting clinical utility of FDG-PET in differentiating among PPA variants was considered as poor. However, the consensual recommendation was defined on Delphi round I, with six out of seven panelists supporting clinical use.
Quantitative evidence demonstrating utility or lack thereof is still missing. Panelists decided consistently to provide interim support for clinical use based on the fact that a typical atrophy or metabolic pattern is needed for PPA according to the diagnostic criteria, and the synaptic failure detected by FDG-PET is an earlier phenomenon than atrophy. Also, a normal FDG-PET points to a non-neurodegenerative cause.
欧洲核医学协会（EANM）和欧洲神经病学学会（EAN）的共同努力旨在为 FDG-PET 在神经退行性疾病中的应用提供临床指导。本文探讨了 FDG-PET 在原发性进行性失语症（PPA）三种形式的鉴别诊断中相对于临床/神经心理学评估的诊断效用。
EANM 和 EAN 任命了 7 名小组成员，并使用协调一致的 PICO（人群、干预、比较、结局）问题关键词进行了文献检索。对研究进行了筛选，以确定其是否符合纳入标准，并提取数据以评估其方法学质量。关键结局是鉴别不同 PPA 临床形式的准确性指标。随后，使用提取的数据和质量评估进行了德尔菲（Delphi）轮次，以根据文献和专家意见达成共识。
在检查的四篇论文中，有四篇提供了这一 PICO 的关键结果。支持 FDG-PET 在鉴别 PPA 变异方面具有临床效用的正式证据水平被认为较差。然而，在第一轮德尔菲中，七位小组成员中的六位支持临床应用，因此定义了共识建议。
目前仍然缺乏证明其效用或缺乏效用的定量证据。小组成员一致决定在缺乏明确证据的情况下，根据诊断标准中 PPA 需要典型的萎缩或代谢模式以及 FDG-PET 检测到的突触功能障碍早于萎缩这一事实，为临床应用提供临时支持。此外，FDG-PET 正常可提示非神经退行性病因。
