The objective of the study is to construct a noninvasive approach 68Ga-MY6349 PET/CT to detect the Trop-2 expression of tumor lesions in patients with solid tumors and to identify patients benefiting from Trop-2 targeting antibody-drug conjugate treatment.

As a new trophoblast cell-surface antigen 2 (Trop-2) targeting PET radiotracer, 68Ga-MY6349 is promising as an excellent imaging agent applicable to various cancers. In this research, subjects with various types of tumors underwent contemporaneous 68Ga-MY6349 and standard-of-care imaging (18F-FDG, 68Ga-PSMA, or 68Ga-DOTATATE PET/CT) either for an initial assessment or for recurrence detection. Tumor uptake was quantified by the maximum standard uptake value (SUVmax). The numbers of positive tumor lesions of standard-of-care imaging and 68Ga-MY6349 PET/CT were recorded by visual interpretation. The diagnostic accuracy of 68Ga-MY6349 was calculated and compared to standard-of-care imaging.

Inclusion Criteria:

1. adult patients (aged 18 years or older);
2. patients with suspected or newly diagnosed or previously treated malignant tumors (supporting evidence may include MRI, CT, tumor markers and pathology report);
3. patients who had scheduled both standard-of-care imaging (18F-FDG, 68Ga-PSMA, or 68Ga-DOTATATE PET/CT) and 68Ga-MY6349 PET/CT scans;
4. 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:

1. patients with pregnancy;
2. the inability or unwillingness of the research participant, parent or legal representative to provide written informed consent.