The added value of [68Ga]Ga-FAPI-46 PET/CT imaging in oncology: a real-world clinical setting

The aim of the study is to evaluate the diagnostic performance of fibroblast activation protein inhibition (FAPI)-PET/CT imaging for cancer patients in a real-world setting.

All patients who underwent FAPI-PET/CT imaging between June 2021 and June 2024 due to a diagnostic dilemma unresolved by routine imaging were included in this single center retrospective analysis. The diagnostic yield, potential impact, diagnostic accuracy, and change in management were evaluated. Reference standard included histology, imaging and/or clinical follow-up for at least six months.

Out of 42 patients presenting with 11 different cancer types (including mainly metastatic colorectal cancer, prostate cancer and cancer of unknown primary), 34 had a positive FAPI-PET/CT scan. All patients with previously on-routine-imaging-identified disease (N.=31) also had a positive FAPI-PET/CT scan. In 64% (95% CI: 50-79%) of the 42 patients, the FAPI-PET/CT revealed additional findings compared to routine imaging, with the potential to directly impact clinical decision-making. Sensitivity, specificity, positive predictive value and negative predictive value of the additional findings were 88% (95% CI: 81-94%), 83% (95% CI: 75-92%), 88% (95% CI: 81-94%), and 83% (95% CI: 75-92%), respectively. FAPI-PET/CT led to a change in management in 45% (95% CI: 30-60%) of all patients.

A substantial added value of FAPI-PET/CT for cancer patients in a real-world setting was demonstrated.