To evaluate the potential usefulness of 68Ga-DOTA-hLAG-3 positron emission tomography/computed tomography (PET/CT) for the evaluation of LAG-3 expression in primary and/or metastatic tumors, compared with histopathological results.

Participants with cancer underwent 68Ga-DOTA-hLAG-3 PET/CT for an initial assessment. Tumor uptake was quantified by the maximum standard uptake value (SUVmax) and mean SUV (SUVmean). In addition, the LAG-3 expression of lesions was confirmed by histopathological analyzing. The quantitative parameters of 68Ga-DOTA-hLAG-3 PET/CT were compared with histopathological result to evaluate the diagnostic efficacy.

Inclusion Criteria:

• (i) adult patients (aged 18 years or order);
• (ii) patients with newly diagnosed or previously treated malignant tumors (supporting evidence may include magnetic resonance imaging (MRI), CT, tumor markers and pathology report);
• (iii) patients who had scheduled 68Ga-NK224 PET/CT scans;
• (iv) patients who were able to provide informed consent (signed by participant, parent or legal representative) and assent according to the guidelines of the Clinical Research Ethics Committee.

Exclusion Criteria:

• (i) patients with non-malignant lesions;
• (ii) patients with pregnancy;
• (iii) the inability or unwillingness of the research participant, parent or legal representative to provide written informed consent.

patients with newly diagnosed or previously treated malignant tumors(supporting evidence may include magnetic resonance imaging (MRI), CT, tumor markers and pathology report)