{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T10:26:08Z","timestamp":1777890368856,"version":"3.51.4"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T00:00:00Z","timestamp":1777593600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>\n                    This mini-review aims to examine how molecular PET and immuno-PET may complement tissue-based biomarkers in gastric cancer immunotherapy by enabling whole-body assessment of target expression, stromal biology, immune effector activity, and treatment-related inflammatory changes. Gastric cancer remains a major global health burden, while immunotherapy is expanding from advanced disease into perioperative and conversion settings. However, clinical benefit remains heterogeneous, and conventional biomarkers such as PD-L1, HER2, and MSI\/dMMR do not fully capture spatial and temporal variation across lesions. Molecular PET broadly encompasses tracers targeting metabolism, receptors, stromal components, and immune biology, whereas immuno-PET uses radiolabeled antibodies or related scaffold proteins to visualize target distribution and, in some settings, pharmacodynamic changes\n                    <jats:italic>in vivo<\/jats:italic>\n                    . Current evidence in gastric cancer suggests potential roles for HER2-targeted PET, FAPI PET, and granzyme B PET in lesion characterization, stromal phenotyping, early response assessment, and prognostic stratification. However, PD-L1 imaging in gastric cancer remains supported mainly by preclinical data, and much of the checkpoint-imaging literature is extrapolated from non-gastric malignancies. Major barriers include limited gastric-cancer-specific prospective cohorts, heterogeneous tracer formats and imaging time points, lack of standardized quantitative thresholds, and a shortage of outcome-driven studies. Overall, molecular PET and immuno-PET should currently be viewed as promising translational tools rather than routine clinical biomarkers, with their greatest near-term value likely lying in multimodal patient stratification and early pharmacodynamic assessment.\n                  <\/jats:p>","DOI":"10.3389\/fimmu.2026.1838846","type":"journal-article","created":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T05:36:19Z","timestamp":1777613779000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Molecular PET and immuno-PET in gastric cancer immunotherapy: current evidence, clinical utilities, and translational barriers"],"prefix":"10.3389","volume":"17","author":[{"given":"Qiang","family":"Hu","sequence":"first","affiliation":[{"name":"Tongde Hospital of Zhejiang Province Affiliated to Zhejiang Chinese Medical University (College of Integrated Traditional Chinese and Western Medicine Clinical 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