68Ga-FAPI PET/CT in diagnosis, staging and management of Gastric Carcinoma: A systematic review and meta-analysis

Articles in Press

Document Type : Meta-Analysis

Authors

1 Department of Nuclear medicine Dr Rajendra Prasad government medical college

2 Department of Nuclear medicine , RGCIRC New Delhi

3 Department of Oncology Dr Rajendra Prasad Government medical college Kangra Himachal Pradesh

10.22038/aojnmb.2026.93248.1690

Abstract

Background: Accurate staging, including detection of nodal and distant metastases of gastric carcinoma is essential for treatment planning. 18F-FDG PET/CT has important limitations in gastric cancer, especially in diffuse and mucinous histologic subtypes. Fibroblast activation protein inhibitor (FAPI) PET/CT targets cancer-associated fibroblasts and may improve lesion conspicuity.



Objective: To systematically review and meta-analyse the diagnostic performance of 68Ga-FAPI PET/CT for staging of gastric carcinoma and to compare it with 18F-FDG PET/CT.



Methods: The protocol was prospectively registered in PROSPERO (CRD420251056976). PubMed, EMBASE, Web of Science and Cochrane libraries were searched from January 2016 to December 2023 for clinical studies evaluating 68Ga-FAPI PET/CT in histologically confirmed gastric carcinoma. Two reviewers independently screened records, extracted data, and assessed risk of bias using QUADAS-2. Pooled sensitivity, specificity, positive and negative predictive values and accuracy were estimated using random effects models. Summary ROC (SROC) and hierarchical SROC (HSROC) curves were generated. Comparative analyses with 18F-FDG PET/CT were restricted to studies with head to head data in the same patient cohort, and areas under the curve (AUCs) were compared with DeLong’s test.



Results: Fourteen studies (681 patients) were included; eleven provided head to head comparisons with 18F-FDG PET/CT. For detection of primary gastric carcinoma with 68Ga-FAPI PET/CT, pooled sensitivity and specificity were 95-96% and 93% respectively, with an AUC of 0.96 (95% CI ~ 0.89-1.00). For metastatic disease, pooled accuracy for lymph node, omental, visceral and skeletal metastases ranged from ~ 89% to 97%. In head to head studies, 68Ga-FAPI PET/CT showed higher AUCs than 18F-FDG PET/CT for primary tumors (0.96 vs 0.76; p = 0.001) and omental metastases (0.97 vs 0.78; p = 2.6×10⁻⁵). Heterogeneity was moderate for most outcomes. Funnel plots and trim and fill analyses suggested possible small study effects, but adjusted pooled diagnostic odds ratios remained high.



Conclusions: 68Ga-FAPI PET/CT demonstrates high diagnostic accuracy for staging of gastric carcinoma and appears to outperform 18F-FDG PET/CT in many settings, particularly for omental and some visceral metastases and for histologic subtypes with low FDG avidity. These findings support the use of 68Ga-FAPI PET/CT as a promising complementary imaging modality for staging and restaging

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Asia Oceania Journal of Nuclear Medicine and Biology

Articles in Press, Accepted Manuscript
Available Online from 08 February 2026

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