The objective of the study is to construct a noninvasive approach using 68Ga-DOTA-AP9 PET/CT to detect the CD147 expression of tumor lesions in patients with solid tumors and to identify patients benefiting from CD147 targeting treatment.

Inclusion Criteria:

1. Malignant melanoma, liver cancer, colon cancer, pancreatic cancer, breast cancer, gastric cancer, lung cancer, etc., confirmed by histopathology or cytology;
2. age ≥18 and ≤75 years old, male or female;
3. ECOG score 0 or 1;
4. expected survival time ≥6 months;
5. There was at least one measurable target lesion according to RECIST1.1 criteria, and biopsy could be performed within one month before and after PET scan, and the patient could provide 2-3 lesion tissue slides;
6. Women of childbearing age (15-49 years) must have had a negative pregnancy test within 7 days before starting testing; Women and men of childbearing potential must agree to use effective contraception to avoid pregnancy during the study and for 3 months after the examination;
7. patients recommended by clinicians to undergo PET/CT examination for tumor staging;
8. The subjects could fully understand and voluntarily participate in this experiment, and signed an informed consent.

Exclusion Criteria:

1. Pregnant or breastfeeding women, or women planning to become pregnant during the study or within three months after administration, as well as individuals donating sperm or oocytes.
2. Individuals known or suspected to be allergic to the investigational drug or any of its components.
3. Individuals with significantly abnormal liver or kidney function: serum total bilirubin (TBIL) > 1.5 × 20 µmol/L, or aspartate aminotransferase (AST) > 2.5 × 45 µmol/L, or alanine aminotransferase (ALT) > 2.5 × 40 µmol/L, or serum creatinine > 1.5 × 130 µmol/L.
4. Unable to cooperate in completing the PET scan, or suffering from claustrophobia or other conditions that prevent cooperation during the PET scan.
5. Other situations deemed inappropriate for participation in the trial by the investigator. Female patients who are pregnant or breastfeeding.

Malignant tumor patients or suspected patients