Increased 68 Ga-FAPI Activity in Benign Pulmonary Nodules

Area of Science:

• Nuclear medicine
• Oncology
• Radiology

Background:

• Positron emission tomography/computed tomography (PET/CT) is crucial for diagnosing pulmonary nodules.
• 18F-FDG PET/CT is commonly used, but its specificity can be limited.
• 68Ga-FAPI PET/CT is an emerging imaging modality for targeting fibroblast activation protein (FAP).

Observation:

• A 68-year-old male presented with pulmonary nodules, suspected to be malignant.
• Both 18F-FDG and 68Ga-FAPI PET/CT demonstrated increased tracer uptake in these nodules.
• Post-surgical histopathology revealed the nodules to be benign.

Findings:

• This case highlights that intense 68Ga-FAPI uptake can be observed in benign pulmonary lesions.
• The findings suggest that high FAP expression, indicated by 68Ga-FAPI uptake, is not exclusively associated with malignancy.
• This challenges the conventional interpretation of increased tracer uptake in PET/CT imaging of pulmonary nodules.

Implications:

• Clinicians should consider the possibility of benign etiologies in pulmonary nodules with high 68Ga-FAPI uptake.
• Further research is warranted to understand the role of FAP in benign pulmonary diseases.
• This may lead to revised diagnostic algorithms for pulmonary nodules evaluated with 68Ga-FAPI PET/CT.