Enrolled patients with pancreatic cancer will undergo whole-body \[89Zr\]Zr-DFO-SHR1920 immunoPET/CT scans at 0,1, 3, 5, or 7 days after tracer injection (1-3 mCi). Uptake of \[89Zr\]Zr-DFO-SHR1920 in tumor and normal organs/tissues will be scored visually and quantitatively. For immunoPET imaging with 18F or 68Ga-labeled 3A12 (a nanobody targeting CLDN18.2), immunoPET/CT scan will be performed 1h after tracer injection (0.05-0.1 mCi/kg).
Tumor uptake will be quantified by the maximum standard uptake value (SUVmax). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy will be calculated to evaluate the diagnostic efficacy. The correlation between lesion uptake and protein expression level determined by immunohistochemistry staining will be further analyzed. The exploration endpoint will be the imaging feasibility and preliminary diagnostic value of the above tracers.
