Journal Article

FZJ-2023-00158

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Head-to-Head Comparison of [68 Ga]Ga-FAPI-46-PET/CT and [18F]F-FDG-PET/CT for Radiotherapy Planning in Head and Neck Cancer

Wegen, S. (Corresponding author) ; van Heek, L. ; Linde, P. ; Claus, K. ; Akuamoa-Boateng, D. ; Baues, C. ; Sharma, S. J. ; Schomäcker, K. ; Fischer, T. ; Roth, K. S. ; Klußmann, J. P. ; Marnitz, S. ; Drzezga, A.FZJ* ; Kobe, C.

2022
Springer Nature Switzerland Cham

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Please use a persistent id in citations: http://hdl.handle.net/2128/33592  doi:10.1007/s11307-022-01749-7

Abstract: Introduction: In head and neck cancers (HNCs), fibroblast activation protein (FAP) is expressed by cancer-associated fibroblasts (CAFs) in the tumor microenvironment. Preliminary evidence suggests that detection and staging is feasible with positron emission tomography (PET/CT) imaging using [68 Ga]-radiolabeled inhibitors of FAP ([68 Ga]Ga-FAPI-46) in HNCs. This study aims to compare [68 Ga]Ga-FAPI-46 PET/CT and [18F]-fluorodeoxy-D-glucose ([18F]F-FDG) PET/CT with a focus on improved target volume definition and radiotherapy planning in patients with HNC referred for chemoradiation.Methods: A total of 15 patients with HNCs received both [68 Ga]Ga-FAPI-46 PET/CT and [18F]F-FDG PET/CT with a thermoplastic mask, in addition to initial tumor staging by conventional imaging with contrast-enhanced CT and/or MRI. Mean intervals between FAPI/FDG and FAPI/conventional imaging were 4 ± 20 and 17 ± 18 days, respectively. Location and number of suspicious lesions revealed by the different procedures were recorded. Subsequently, expert-generated gross tumor volumes (GTVs) based on conventional imaging were compared to those based on [18F]F-FDG and [68 Ga]Ga-FAPI-46 PET/CT to measure the impact on subsequent radiation planning.Results: All patients had focal FAPI uptake above background in tumor lesions. Compared to FDG, tumor uptake (median SUVmax 10.2 vs. 7.3, p = 0.008) and tumor-to-background ratios were significantly higher with FAPI than with FDG (SUVmean liver: 9.3 vs. 3.2, p < 0.001; SUVmean bloodpool: 6.9 vs. 4.0, p < 0.001). A total of 49 lesions were recorded. Of these, 40 (82%) were FDG+ and 41 (84%) were FAP+. There were 5 (10%) FAP+/FDG- lesions and 4 (8%) FAP-/FDG+ lesions. Volumetrically, a significant difference was found between the GTVs (median 57.9 ml in the FAPI-GTV, 42.5 ml in the FDG-GTV, compared to 39.2 ml in the conventional-GTV). Disease stage identified by FAPI PET/CT was mostly concordant with FDG PET/CT. Compared to conventional imaging, five patients (33%) were upstaged following imaging with FAPI and FDG PET/CT.Conclusion: We demonstrate that [68 Ga]Ga-FAPI-46 -PET/CT is useful for detecting tumor lesions in patients with HNCs. There is now a need for prospective randomized studies to confirm the role of [68 Ga]Ga-FAPI-46 PET/CT in relation to [18F]F-FDG PET/CT in HNCs and to evaluate its impact on clinical outcome.Keywords: FAPI; FDG/PET; Head and neck cancer; PET-based; Radiotherapy planning.

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Contributing Institute(s):

1. Molekulare Organisation des Gehirns (INM-2)

Research Program(s):

1. 899 - ohne Topic (POF4-899) (POF4-899)

Appears in the scientific report 2022

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; DEAL Springer ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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