Renal brosis is a pathological state in the progression of chronic kidney disease. Early detection and treatment are vital to prolong the survival of patients. Renal puncture examination represents the gold standard examination method for renal brosis, but it has several limitations. This study aims to evaluate the diagnostic performance of a novel PET radiotracer, [ 68 Ga]Ga-broblast activation protein inhibitor (FAPI)-04, which speci cally images broblast activation protein (FAP) expression for renal brosis. MethodsAll patients underwent renal puncture before receiving [ 68 Ga]Ga-FAPI-04 PET/CT imaging. They then underwent [ 68 Ga]Ga-FAPI-04 PET/CT and immunochemistry examinations, and the data obtained were analyzed. ResultsThe [ 68 Ga]Ga-FAPI-04 PET/CT examination results showed that almost all patients (12/13) exhibited increased radiotracer uptake. The maximum standardized uptake value (SUVmax) in patients with mild, moderate, and severe brosis was 3.92±1.50, 5.98±1.6, and 7.67±2.23, respectively. ConclusionCompared with renal puncture examination, non-invasive imaging of FAP expression through [ 68 Ga]Ga-FAPI-04 PET/CT can quickly show the patient's bilateral kidney condition with high sensitivity. This can facilitate the evaluation of the patient's disease progression, diagnosis, and the development of a treatment plan.

68Ga-FAPI PET/CT has been used in the evaluation of a variety of malignancies. An increasing number of case studies on FAPI uptake in nonmalignant diseases is also gaining support and enthusiasm. We present a case of asymptomatic chronic cholecystitis and degenerative osteophyte detected incidentally by 68Ga-FAPI PET/CT.

PurposeThis study aimed to compare the potential diagnostic efficacy of gallium68-fibroblast-activation protein inhibitor ([68Ga]Ga-FAPI-04) and fluorine18-fluorodeoxyglucose ([18F]-FDG) positron emission tomography-computed tomography (PET/CT) for primary tumors, lymph nodes, and distant metastatic lesions of gastric cancer (GC), and to explore the effects of [68Ga]Ga-FAPI-04 and [18F]-FDG on tumor staging and restaging in GC.MethodsThis single-center retrospective study (NCT2100044131) was conducted at the Affiliated Hospital of the Southwest Medical University between June 2020 and December 2021. Images of patients with GC who were pathologically confirmed and underwent contemporaneous [18F]-FDG and [68Ga]Ga-FAPI-04 PET/CT within 1 week were analyzed. The diagnostic efficacy of [68Ga]Ga-FAPI-04 PET/CT and [18F]-FDG PET/CT for TNM staging of GC was compared using McNemar test. The maximum standard uptake value (SUVmax) of each lesion in the two imaging types was compared using the Mann-Whitney U test.ResultsIn total, 25 patients with GC (mean age, 56 ± 12 years) were evaluated. [68Ga]Ga-FAPI-04 PET/CT exhibited higher sensitivity compared to [18F]-FDG PET/CT for detecting primary tumors (18/19 [94.74%] vs. 13/19 [68.42%], χ2 = 6.866, P < 0.01), lymph node metastasis (75/77 [97.40%] vs. 32/77 [41.56%], χ2 = 2.888, P =0.089), and distant metastases (275/283 [97.17%] vs. 122/283 [43.11%], χ2 = 11.858, P < 0.01). [68Ga]Ga-FAPI-04 accumulation was significantly higher than that of [18F]FDG in tumors (median SUVmax, 10.28 vs 3.20; U=59.00, P < 0.01), lymph node metastasis metastases (median SUVmax, 9.20 vs 3.15; U=53.50, P < 0.01), and distant metastases (median SUVmax, 8.00 vs 4.20; U=200.00, P < 0.01). Compared to [18F]-FDG PET/CT, [68Ga]Ga-FAPI-04 PET/CT resulted in new oncological findings in 14/25 patients and corrected tumor staging or restaging in 7/25 patients.ConclusionOur preliminary results regarding the impact of [68Ga]Ga-FAPI-04 PET/CT on tumor staging highlight the potential of this approach for increasing the accuracy of GC diagnosis, which may facilitate treatment decision-making.