Diagnostic Value of ⁶⁸Ga-FAPI PET/CT Versus ¹⁸F-FDG PET/CT in Laryngeal Cancer Staging

To investigate whether gallium-68 fibroblast activation protein inhibitor positron emission tomography/computed tomography ⁶⁸Ga-FAPI PET/CT is superior to ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG) PET/CT in the staging of patients with laryngeal cancer (LC).

A total of 14 patients diagnosed with LC were retrospectively included in the study, of whom 13 were male and 1 female, with a mean age of 65 years. All participants were initially referred to our department for staging with ¹⁸F-FDG PET/CT. Subsequently, each patient underwent a ⁶⁸Ga-FAPI PET/CT scan three days following the ¹⁸F-FDG PET/CT. Both sets of imaging studies were independently evaluated by two experienced nuclear medicine physicians, and the findings were systematicaly compared to assess potential differences in diagnostic performance.

The median maximum standard uptake values (SUV_max) of primary tumors was significantly higher in ⁶⁸Ga-FAPI PET/CT 10.95; range: 3.5-19.2) compared to ¹⁸F-FDG PET/CT (4.85; range: 2.2-10.9). Lymph node involvement was observed on FDG scans in 3 patients, in ipsilateral levels 2 and/or 3, with a median SUV_max of 3.7 (range: 2.4-4.1). FAPI PET/CT also detected lymph node involvement at the same levels in 3 patients, with a notably higher SUV_max of 7.9 (range: 6.8-10.4).

In this study, our results suggest that ⁶⁸Ga-FAPI PET/CT demonstrates superior radiotracer uptake in both primary tumors and lymph nodes, which may enhance detection sensitivity for LC staging compared with ¹⁸F-FDG PET/CT. Nevertheless, further prospective studies with larger patient populations are warranted to validate these preliminary observations and determine the clinical value of this emerging imaging modality.