biostudies-literatureZettlitz KANCI NIH HHSNational Institutes of HealthNIH HHS489-500https://www.ebi.ac.uk/biostudies/studies/S-EPMC6580847biostudies-literatureUnknown46(2)<h4>Purpose</h4>Metabolic imaging using [¹⁸F]FDG is the current standard for clinical PET; however, some malignancies (e.g., indolent lymphomas) show low avidity for FDG. The majority of B cell lymphomas express CD20, making it a valuable target both for antibody-based therapy and imaging. We previously developed PET tracers based on the humanised anti-CD20 antibody obinutuzumab (GA101). Preclinical studies showed that the smallest bivalent fragment, the cys-diabody (GAcDb, 54.5 kDa) with a peak uptake at 1-2 h post-injection and a biological half-life of 2-5 h, is compatible with short-lived positron emitters such as fluorine-18 (¹⁸F, t_1/2 110 min), enabling same-day imaging.<h4>Methods</h4>GAcDb was radiolabeled using amine-reactive N-succinimidyl 4-[<supEuropean journal of nuclear medicine and molecular imaging¹⁸F-labeled anti-human CD20 cys-diabody for same-day immunoPET in a model of aggressive B cell lymphoma in human CD20 transgenic mice.PMC6580847CA149254P30 CA016042R21 CA212718CA212718R01 CA149254R01 CA174294CA016042Wu AMTsai WKTavare RZettlitz KAvan Dam RMYamada RETimmerman JMHa NSCollins Jfalse¹⁸F-labeled anti-human CD20 cys-diabody for same-day immunoPET in a model of aggressive B cell lymphoma in human CD20 transgenic mice.<h4>Purpose</h4>Metabolic imaging using [¹⁸F]FDG is the current standard for clinical PET; however, some malignancies (e.g., indolent lymphomas) show low avidity for FDG. The majority of B cell lymphomas express CD20, making it a valuable target both for antibody-based therapy and imaging. We previously developed PET tracers based on the humanised anti-CD20 antibody obinutuzumab (GA101). Preclinical studies showed that the smallest bivalent fragment, the cys-diabody (GAcDb, 54.5 kDa) with a peak uptake at 1-2 h post-injection and a biological half-life of 2-5 h, is compatible with short-lived positron emitters such as fluorine-18 (¹⁸F, t_1/2 110 min), enabling same-day imaging.<h4>Methods</h4>GAcDb was radiolabeled using amine-reactive N-succinimidyl 4-[<sup2019-01-01T00:00:00Z2019 Feb2025-04-22T14:13:22.353Z2020-10-29T11:02:32ZS-EPMC65808473045647510.1007/s00259-018-4214-x