Open Access
CC BY-NC-ND 4.0 · World J Nucl Med 2022; 21(01): 085-098
DOI: 10.1055/s-0042-1749225
Presentation Abstracts

Diagnostic Guidance for Patients with Persistent Pulmonary Abnormalities after COVID-19 Infection: The Potential Benefit of 68Ga-FAPI PET/CT

Hanna Svirydenka
1   Department of Nuclear Medicine, Medical University of Innsbruck, Innsbruck, Austria
,
Anna Boehm
2   Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
,
Irene Virgolini
1   Department of Nuclear Medicine, Medical University of Innsbruck, Innsbruck, Austria
,
Frederik L. Giesel
3   Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
,
Uwe Haberkorn
3   Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
,
Judith J. Loeffler-Ragg
2   Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
,
Gerlig Widmann
4   Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria
› Author Affiliations
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    • Areas of Interest: COVID-19

    Background: COVID-19-related pneumonia challenges nowadays clinical practice. We aimed to explore the potential diagnostic benefit of PET/CT in further characterization of the underlying pathophysiological mechanisms of impaired pulmonary convalescence to establish a model for individual anti-inflammatory or antifibrotic treatment.

    Methods: Five confirmed COVID-19 patients suspected of pulmonary fibrosis were scheduled for the dual tracer PET/CT with 18F-FDG and 68Ga-fibroblast activation protein inhibitor (FAPI)-46. SUVs max of FAPI and FDG PET scans in the involved lung tissue of post COVID-19 patients were calculated and corrected for background. SUVmax/BG rations were obtained for each patient. We also compared the SUV maximum at 1 hour and SUVmax/BG rations of FAPI in post COVID-19 patients group to the control group of extrapulmonary oncological patients with different tumor and no known previous neither COVID-19 nor lung pathology.

    Results: The median SUVmax of 68Ga-FAPI within the pulmonary abnormalities in post COVID-19 patients was 3.4 ± 0.84 after 1 hour and a median SUVmax/BG ratio at 1 hour of 1.6 ± 0.5. The median SUVmax of 68Ga-FAPI within the pulmonary parenchyma in control group after 1 hour was 1.1 ± 0.23 and a median SUVmax/BG ratio at 1 hour of 0.69 ± 0.33, respectively. 18F-FDG PET/CT in post-COVID-19 group was not able to reveal any significant change of SUV max in residual fibrotic lesions: median SUVmax pulmonary lesions 1.4 ± 0.17 with median SUVmax/BG ratio 0.38 ± 0.1.

    Conclusion: This first case series with a head-to-head comparison not only of 18F-FDG PET/CT and 68Ga-FAPI PET/CT in suspected infection-triggered pulmonary fibrosis but also 68Ga-FAPI PET/CT of post-COVID-19 patients to FAPI imaging of the control group. Indicating fibrotic repair mechanisms, 68Ga-FAPI PET/CT may enhance noninvasive clinical diagnostic performance, drive therapeutic interventions, and facilitate therapeutic response monitoring in patients with long-term CT-abnormalities after sever COVID-19.


     

    No conflict of interest has been declared by the author(s).

    Publication History

    Article published online:
    10 May 2022

    © 2022. World Association of Radiopharmaceutical and Molecular Therapy (WARMTH). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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