We evaluated the potential usefulness of [⁶⁸Ga]Ga-DOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT) for the diagnosis of primary and metastatic lesions in various types of cancer, compared with [¹⁸F] FDG PET/CT.

A total of 75 patients with various types of cancer underwent contemporaneous [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F] FDG PET/CT either for an initial assessment or for recurrence detection. Tumour uptake was quantified by the maximum standard uptake value (SUV_max). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of [¹⁸F] FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT were calculated and compared to evaluate the diagnostic efficacy.

The study cohort consisted of 75 patients (47 males and 28 females; median age, 61.5 years; age range, 32–85 years). Fifty-four patients with 12 different tumour entities underwent paired [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F] FDG PET/CT for initial assessment, while the other 21 patients underwent paired scans for recurrence detection. [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT was able to clearly identify 12 types of malignant tumours with favourable tumour-to-background contrast, which resulted in a higher detection rate of primary tumours than did [¹⁸F] FDG PET/CT (98.2% vs. 82.1%, P = 0.021). Meanwhile, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT showed a better sensitivity than [¹⁸F] FDG PET/CT in the detection of lymph nodes (86.4% vs. 45.5%, P = 0.004) and bone and visceral metastases (83.8% vs. 59.5%, P = 0.004).

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT showed a superior diagnostic efficacy than [¹⁸F] FDG PET/CT for the diagnosis of primary and metastatic lesions in patients with various types of cancer, especially in identifying liver metastases, peritoneal carcinomatosis, and brain tumours.