Head-to-head comparison of [¹⁸F]FDG PET and [⁶⁸Ga]Ga-FAPI-04 PET in the diagnosis of gastric and pancreatic cancer: a systematic review and meta-analysis

Our meta-analysis aimed to compare the positivity rates of [⁶⁸Ga]Ga-FAPI-04 PET and [¹⁸F]FDG PET in gastric and pancreatic cancer.

We conducted a comprehensive search of PubMed, Embase, and Web of Science databases up to May 2023. The selected studies focused on evaluating the positivity rates of [¹⁸F]FDG PET and [⁶⁸Ga]Ga-FAPI-04 PET in detecting gastric and pancreatic cancer.

A total of 2,401 studies were screened and 13 articles were finally included. The positivity rates of [¹⁸F]FDG PET for primary gastric cancer, lymph node and peritoneal metastases were 0.74 [95% confidence interval (CI): 0.55–0.89], 0.49 (95% CI: 0.33–0.65) and 0.52 (95% CI: 0.37–0.67), respectively. On the other hand, [⁶⁸Ga]Ga-FAPI-04 PET demonstrated significantly higher positivity rates at 0.98 (95% CI: 0.92-1.00), 0.76 (95% CI: 0.60–0.89) and 0.99 (95% CI: 0.93-1.00) (P < 0.01,P = 0.02, P < 0.01), respectively. For pancreatic cancer, [¹⁸F]FDG PET showed positivity rates of 0.93 (95% CI: 0.76-1.00) and 0.46 (95% CI: 0.23–0.69) for primary cancer and lymph node metastases, respectively. In comparison, [⁶⁸Ga]Ga-FAPI-04 PET showed similar positivity rates of 1.00 (95% CI: 0.94-1.00) and 0.68 (95% CI: 0.40–0.90), (P = 0.27, 0.23). There was no significant difference in histopathological positivity rates for signet ring cell carcinoma and TNM stages I and II-IV (P = 0.96, 0.85,0.56).

[⁶⁸Ga]Ga-FAPI-04 PET exhibited a higher positivity rate compared to [¹⁸F]FDG PET in the detection of primary gastric cancer, lymph node and peritoneal metastases. For pancreatic cancer, both [¹⁸F]FDG PET and [⁶⁸Ga]Ga-FAPI-04 PET demonstrated comparable, high positivity rates for primary cancer diagnosis and lymph node metastasis detection. There is still a requirement for more extensive and forward-looking research in this field.