Appropriate use criteria for dementia amyloid imaging in Switzerland – mini-review and statement on behalf of the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics

While FDG-PET imaging of the brain for the differential diagnosis of dementia has been covered by the compulsory health insurance in Switzerland for more than a decade, beta-amyloid-PET just recently has been added to the catalogue of procedures that have been cleared for routine use, provided that a set of appropriate use criteria (AUC) be followed. To provide guidance to dementia care practitioners, the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics jointly report a mini-review on beta-amyloid-PET and discuss the AUC set into effect by the Swiss Federal Office of Public Health, as well as their application and limitations.Die Beta-Amyloid-PET-Bildgebung des Gehirns ist mit der Zulassung für die klinische Routineanwendung durch Swissmedic von 3 EU-weit bereits länger kommerziell verfügbaren Amyloid-β-PET-Radiopharmaka nun auch in dem Nicht-EU-Land Schweiz allgemein verfügbar geworden. Seit dem 01.04.2020 unterliegt die Anwendung von Beta-Amyloid-PET der gesetzlichen Leistungspflicht durch die obligatorische Schweizer Krankenversicherung für die Differenzialdiagnose demenzieller Erkrankungen unter bestimmten Voraussetzungen.Im Namen der Schweizer Gesellschaft für Nuklearmedizin (SGNM) und der Schweizer Memory-Kliniken publiziert die AG Neuronuklearmedizin der SGNM die aktuell gültigen Anwendungskriterien im Rahmen der gesetzlichen Leistungspflicht in der Schweiz, um sowohl den verordnenden Demenzspezialisten, Gerontopsychiatern und Neurologen, als auch den durchführenden Nuklearmedizinern Handlungsempfehlung an die Hand zu geben und einen aktuellen Kurzüberblick über Möglichkeiten und Grenzen der Beta-Amyloid-Bildgebung im klinischen Alltagskontext zu geben

Early metabolic responses in temozolomide treated low-grade glioma patients

Amino acid transport and protein synthesis are important steps of tumor growth. We investigated the time course of tumor metabolism in low-grade gliomas (LGG) during temozolomide chemotherapy, and compared metabolic responses as measured with positron emission tomography (PET) with volume responses as revealed by magnetic resonance imaging (MR). A homogeneous population of 11 patients with progressive non-enhancing LGG was prospectively studied. Imaging was done at 6-months intervals starting six months, and in a second series starting three months after treatment initiation. F-18 fluoro-ethyl-l-tyrosine (FET) uptake was quantified with PET as metabolically active tumor volume, and was compared with the tumor volume on MR. Response was defined as ≥10% reduction of the initial tumor volume. Eight patients showed metabolic responses. Already 3 months after start of chemotherapy the active FET volumes decreased in 2 patients to a mean of 44% from baseline. First MR volume responses were noted at 6 months. Responders showed a volume reduction to 31 ± 23% (mean ± SD) from baseline for FET, and to 73 ± 26% for MR. The time to maximal volume reduction was 8.0 ± 4.4 months for FET, and 15.0 ± 3.0 months for MR. The initial metabolic response correlated with the best volume response on MR (Spearman Rank P = 0.011). Deactivation of amino acid transport represents an early indicator of chemotherapy response in LGG. Response assessment based on MR only has to be reconsidered. The time window obtained from PET may assist for individual treatment decisions in LGG patients