This study will investigate the safety and preliminary diagnostic efficacy of [68Ga]Ga-NOTA-T4 or [18F]AlF-RESCA-T4 in pancreatic cancer, breast cancer, head and neck cancer, lung cancers and other types of solid tumors. Then, this study will provide a new method for the noninvasive target-specific diagnosis of pancreatic cancer, breast cancer, head and neck cancer, lung cancers and other types of solid tumors. PET imaging of TROP-2 will be integrated to TROP-2-targeted therapies in some of the included patients. Therefore, PET imaging with [68Ga]Ga-NOTA-T4 or [18F]AlF-RESCA-T4 will help select patients for targeted therapy and monitor treatment responses after the treatment.

Inclusion Criteria:

1. Be between 18 and 65 years of age and of either sex.
2. Patients with colorectal cancer confirmed by puncture or surgical pathology.
3. Written informed consent signed by the subject or legal guardian or caregiver.
4. Willingness and ability to cooperate with all programs of this study.

Exclusion Criteria:

1. Severe hepatic or renal insufficiency;
2. Targeted therapy before radiotherapy or PET/CT scan；
3. Renal function: serum creatinine less than or equal to the upper limit of the normal range;Liver function: bilirubin, AST(SGOT)/ALT(SGPT) less than or equal to the upper limit of the normal range；
4. History of serious surgery in the last month. Those who have participated in other clinical trials during the same period.