The objective of this study is to construct a noninvasive approach using 68Ga- Mirc415 PET/CT to detect the PD-L2 expression of tumor lesion in patients with colorectal cancer, lung cancer and other solid tumor to identify patients benefiting from anti-PD-(L)1 treatment.

Inclusion Criteria:

1. Aged 18-75, male and female, with ECOG score of 0 or 1;
2. Subjects with head and neck tumors, lung cancer, esophageal cancer, breast cancer, ovarian cancer, cholangiocarcinoma, colorectal cancer, gastric cancer, pancreatic cancer, melanoma, bone or soft tissue sarcoma, solid tumors or suspected tumor subjects who intend to undergo pathological tissue biopsy or receive tumor surgical treatment in the near future (within 2 months);
3. The expected survival was more than 26 weeks;
4. Blood routine test, liver and kidney function meet the following standards: blood routine: WBC >= 4.0 x 10^9/L or neutrophil >= 1.5 x 10^9/:, PLT >= 100 x 10^9 / L, Hb >= 90g / L; Pt or APTT <= 1.5 upper limit of normal value; liver and kidney function: total bilirubin <= 1.5 x ULT (upper limit of normal value), ALT / AST <= 2.5 upper limit of normal value or <= 5 x ULT (subject with liver metastasis), ALP <= 2.5 upper limit of normal value (if bone metastasis or liver metastasis exists, ALP <= 4.5 upper limit of normal value); BUN <= 1.5 x ULT, SCR <= 1.5 x ULT;
5. According to RECIST1.1, there was at least one measurable target lesion;
6. Women must take effective contraceptive measures during the study period and within 6 months after the end of the study; men should agree to use contraceptive measures during the study period and within 6 months after the end of the study period;
7. Understand and sign informed consent voluntarily with good compliance.

Exclusion Criteria:

1. The function of liver and kidney was seriously abnormal;
2. Preparation for pregnant, pregnant and lactating women;
3. Inability to lie flat for half an hour;
4. Suffering from claustrophobia or other mental disorders; 5) Other researchers considered it unsuitable to participate in the trial. -