Head-to-head Intra-individual Comparison of Biodistribution and Tumor Uptake of [¹⁸F]FAPI-74 and [¹⁸F]FDG-PET/CT in Patients with PDAC

Ziel/Aim Pancreatic ductal carcinoma (PDAC) is epithelial cancer with prominent tumor stroma which, in line with>90% of other epithelial malignancies, exhibits a marked overexpression of fibroblast activation protein (FAP). Thus, Ga-labeled FAP ligands have provided very promising clinical results. However, due to well-known limitations regarding the use of Ga-labeling of radiopharmaceuticals, great efforts have been made to employ F-18 labeled FAP derivatives, i.e. [¹⁸F]FAPI-74. With this analysis of interim data from our ongoing prospective, proof-of-concept study, we sought to evaluate the biodistribution, tumor uptake, and lesion detectability in 5 patients with PDAC using [¹⁸F]FAPI-74 compared to [¹⁸F]FDG and contrast-enhanced CT, the current modality of choice for PDAC staging on an intraindividual basis.

Methodik/Methods All patients underwent both [¹⁸F]FDG with contrast-enhanced CT and [¹⁸F]FAPI-74 PET/CT PET imaging with a mean scan time interval of 9 days for primary staging (n=4) or re-staging (n=1). PET scans were acquired 60 min after administration of the tracers. Tracer uptake of the primary and metastatic lesions was assessed by measurements of SUV.

Ergebnisse/Results We detected 19 lesions in 5 patients. [¹⁸F]FAPI-74 detected 15% more lesions compared to [¹⁸F]FDG. All the lesions demonstrated markedly elevated uptake of [¹⁸F]FAPI-74 with a simultaneous lower uptake in the background, providing a very high contrast.

Schlussfolgerungen/Conclusions To our best knowledge, this is the first intra-individual investigation comparing [¹⁸F]FAPI-74 with [¹⁸F]FDG in PDAC with very promising results. These promising results support further investigation with larger, prospective-designed studies.

Publikationsverlauf

Artikel online veröffentlicht:
30. März 2023