Evaluating the diagnostic performance of [F]ALF-NOTA-FAPI-04 PET/CT in gastric cancer: a comparative study with [F]FDG PET/CT.

Purpose: To compare the diagnostic value of [F]ALF-NOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT) and F-fluorodeoxyglucose (FDG) PET/CT in gastric cancer.

Methods: This single-center retrospective analysis included 65 patients with gastric cancer who received both [F]FDG and [F]ALF-NOTA-FAPI-04 PET/CT for initial staging or restaging. Histopathological manifestations, typical imaging manifestations, follow-up imaging, and comprehensive clinical assessment were used as reference criteria. The uptakes of [F]FDG and [F]ALF-NOTA-FAPI-04 PET were compared using the Wilcoxon signed-rank test. McNemar's test was employed to compare the diagnostic performance of the two imaging techniques.

Results: A total of 65 patients were included (26 male and 39 female; mean age, 54.03 ± 10.41 years), Among them, 10 were newly diagnosed, 46 underwent radical gastrectomy, and 9 received only chemotherapy prior to the study. Compared with [F]FDG PET/CT, [F]ALF-NOTA-FAPI-04 PET/CT showed higher sensitivity in primary or recurrent tumors (100% vs. 64.52%, p < 0.001)), lymph node metastases (88.89% vs. 38.89%, p = 0.006), distant metastases (91.18% vs. 50%, p < 0.001). From the semi-quantitative evaluation, the Maximum standardized uptake value (SUVmax) and target-to-background ratio of [F]ALF-NOTA-FAPI-04 PET/CT were significantly higher than that of [F]FDG PET/CT in primary or recurrent tumors, lymph node metastases, and distant metastases (all p < 0.001).

Conclusion: Our study results indicate that [F]ALF-NOTA-FAPI-04 PET/CT outperforms [F]FDG PET/CT in the detection of primary or recurrent tumors, lymph node metastasis, and distant metastasis in gastric cancer.

Key Points: Question Early diagnosis and precise staging of gastric cancer are crucial for patient prognosis; however, current imaging techniques still face significant limitations. Findings [F]ALF-NOTA-FAPI-04 PET/CT demonstrated significantly higher sensitivity than [F]FDG PET/CT in detecting primary or recurrent tumors and metastases in patients with gastric cancer. Clinical relevance [F]ALF-NOTA-FAPI-04 PET/CT is an advanced imaging diagnostic technique that significantly enhances the diagnostic accuracy for gastric cancer and its metastatic lesions. This technology provides robust support for clinical decision-making, thereby improving the management of patients with gastric cancer.