Al18F-NOTA-FAPI-04 PET/CT vs. 18F-FDG in gastric adenocarcinoma: findings from a preliminary prospective comparative study
Abstract
To conduct a head-to-head comparison of the clinical value of Al 18 F-NOTA-FAPI-04 PET/CT and 18 F-FDG PET/CT in the diagnosis of gastric adenocarcinoma. Fourteen patients with gastric cancer who underwent diagnosis and treatment at the Affiliated Hospital of North Sichuan Medical College between July 2023 and January 2024 were prospectively enrolled. All patients underwent both imaging modalities within one week. The Wilcoxon signed-rank test or McNemar test was used to compare the standardized uptake value maximum (SUVmax), standardized uptake value mean (SUVmean), tumor-to-background ratio (TBR), and positive detection rates between the two methods. The positive detection rate of Al 18 F-NOTA-FAPI-04 PET/CT for primary gastric lesions or postoperative recurrences was 100% (11/11), while 18 F-FDG PET/CT detected 90.9% (10/11). The tumor-to-background ratio (TBR) for these lesions was significantly higher with Al 18 F-NOTA-FAPI-04 PET/CT compared to 18 F-FDG PET/CT ( z = -2.20, P = 0.028). Among 12 patients with lymph node metastasis confirmed by pathology or suggested by imaging follow-up (total of 169 lymph nodes), Al 18 F-NOTA-FAPI-04 PET/CT showed a higher detection rate of suspicious lymph node metastases than 18 F-FDG PET/CT [98.2% (166/169) vs. 61.5% (104/169); P < 0.001]. The SUVmax, SUVmean, and TBR of lymph node metastases were significantly higher with Al 18 F-NOTA-FAPI-04 PET/CT than with 18 F-FDG PET/CT ( z = -2.76, P = 0.006; z = -3.01, P = 0.003; z = -5.10, P < 0.001, respectively). Similarly, the TBR for distant metastases was significantly higher with Al 18 F-NOTA-FAPI-04 PET/CT compared to 18 F-FDG PET/CT ( z = -3.4, P = 0.001). In three patients with peritoneal metastases, the SUVmax, SUVmean, and TBR for peritoneal lesions were significantly higher with Al 18 F-NOTA-FAPI-04 PET/CT than with 18 F-FDG PET/CT ( z = -2.52, P = 0.012 for all comparisons). Al 18 F-NOTA-FAPI-04 PET/CT demonstrates markedly improved detection capabilities for primary gastric lesions, lymph node metastases, and peritoneal metastases compared to 18 F-FDG PET/CT, providing a novel reference for imaging-based diagnosis and staging of gastric cancer.