Imaging Properties and Tumor Targeting of 68Ga-NeoBOMB1, a Gastrin-Releasing Peptide Receptor Antagonist, in GIST Patients

Autor: Leonhard Gruber, Clemens Decristoforo, Christian Uprimny, Peter Hohenberger, Stefan O. Schoenberg, Francesca Orlandi, Maurizio Franco Mariani, Claudia Manzl, Maria Theresia Kasseroler, Herbert Tilg, Bettina Zelger, Werner R. Jaschke, Irene J. Virgolini
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Biomedicines, Vol 10, Iss 11, p 2899 (2022)
Druh dokumentu: article
ISSN: 2227-9059
DOI: 10.3390/biomedicines10112899
Popis: Background: Gastrin-releasing peptide receptors (GRPRs) are molecular imaging targets in multiple malignancies. Recently, NeoBOMB1, a 68Ga-labelled antagonist to GRPRs, was developed for PET. Here we report the outcome of a Phase I/IIa clinical trial (EudraCT 2016-002053-38) describing diagnostic properties and covariates influencing uptake of 68Ga-NeoBOMB1 in oligometastatic gastrointestinal stromal tumor (GIST) patients. Methods: Nine patients with advanced GIST using PET/CT (computed tomography) were included. After kit-based 68Ga-NeoBOMB1 preparation with a licensed 68Ge/68Ga generator, 3 MBq/kg body weight were injected intravenously. PET/CT included dynamic and static PET scans 5, 12 and 18 min and 1, 2, and 3–4 h post injection (first six patients) and static PET scans 2 and 3–4 h post injection (last three participants). Tumor targeting was assessed on a per-lesion and per-patient basis. Results: Six patients showed visible radiotracer uptake in at least one tumor lesion. Seventeen out of 37 tumor lesions exhibited significant 68Ga-NeoBOMB1 uptake (median SUVmax 11.8 [range 2.8–51.1] 2 h p.i. and 13.2 [range 2.5–53.8] 3–4 h p.i) and improved lesion-to-background contrast over time. Five lesions (13.5%) were identified only by 68Ga-NeoBOMB1-PET, with no correlation on contrast-enhanced CT. Three patients showed no radiotracer accumulation in any lesions. Tracer uptake correlated with male sex (p < 0.0001), higher body mass index (p = 0.007), and non-necrotic lesion appearance (p = 0.018). There was no association with whole-lesion contrast enhancement, hepatic localization, mutational status, or disease duration. Conclusions: 68Ga-NeoBOMB1-PET exhibits variable tumor uptake in advanced-stage GIST patients, correlating with lesion vitality based on CT contrast uptake, opening the possibility of a theragnostic approach in selected cases.
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