What do we know About the Usefulness of F-FDG PET-CT for the Management of Invasive Fungal Infection? An International Survey.

Background: Recent data support F-FDG PET-CT for the management of infections in immunocompromised patients, including invasive fungal infection (IFI). However, its role is not well established in clinical practice. We performed an international survey to evaluate the knowledge of physicians about the usefulness of F-FDG PET-CT in IFI, in order to define areas of uncertainty.

Methods: An online survey was distributed to infectious diseases working groups in December 2023-January 2024. It included questions regarding access to F-FDG PET-CT, knowledge on its usefulness for IFI and experience of the respondents. A descriptive analysis was performed.

Results: 180 respondents answered; 60.5% were Infectious Diseases specialists mainly from Spain (52.8%) and Italy (23.3%). 84.4% had access to F-FDG PET-CT at their own center. 85.6% considered that F-FDG PET-CT could be better than conventional tests for IFI. In the context of IFI risk, 81.1% would consider performing F-FDG PET-CT to study fever without a source and around 50% to evaluate silent lesions and 50% to assess response, including distinguishing residual from active lesions. Based on the results of the follow-up F-FDG PET-CT, 56.7% would adjust antifungal therapy duration. 60% would consider a change in the diagnostic or therapeutic strategy in case of increased uptake or new lesions. Uncovering occult lesions (52%) and diagnosing/excluding endocarditis (52.7%) were the situations in which F-FDG PET-CT was considered to have the most added value. There was a great variability in responses about timing, duration of uptake, the threshold for discontinuing treatment or the influence of immune status.

Conclusion: Although the majority considered that F-FDG PET-CT may be useful for IFI, many areas of uncertainty remain. There is a need for protocolized research to improve IFI management.