This project utilizes LRRC15-specific targeted PET radiotracers to perform PET/MR or PET/CT imaging on healthy volunteers and patients with clinically suspected or confirmed malignancies characterized by high LRRC15 expression-including pancreatic cancer, breast cancer, lung cancer, sarcoma, head and neck tumors, glioblastoma, colorectal cancer, and melanoma. The study aims to achieve the following objectives:

For patients with malignant tumors: To diagnose and stage the disease. By comparing the imaging results against the gold standard of histopathological diagnosis, the study aims to evaluate diagnostic efficacy, ascertain the presence or absence of lesions, and characterize their anatomical location and nature. Furthermore, through comparison with [¹⁸F]FDG PET or [⁶⁸Ga]Ga-FAPI PET, the study seeks to achieve accurate disease staging, assess tumor burden, and facilitate therapeutic decision-making.

For healthy volunteers: To conduct pharmacokinetic analyses to determine the in vivo biodistribution and metabolic patterns of the radiotracer, as well as to evaluate its safety profile.

Inclusion Criteria:

Each subject must meet all of the following inclusion criteria to be eligible for study enrollment:

1. The subject or their legally authorized representative (LAR) is capable of providing a signed and dated informed consent form (ICF);
2. Willing and able to comply with all study procedures and cooperate throughout the entire duration of the study;
3. Adult patients or healthy volunteers, aged 18 years or older, male or female;
4. Patients with clinically suspected or confirmed malignancies (supported by evidence such as relevant serum tumor markers, imaging modalities including ultrasound, CT, and MRI, or histopathological examinations) who are in good general condition;
5. Women of childbearing potential (WOCBP) must have used effective contraception for at least one month prior to screening and agree to continue contraceptive use throughout the study period and for a specified duration following study completion;
6. Must meet any other protocol-specified inclusion criteria.

Exclusion Criteria:

Any subject meeting any of the following baseline criteria will be excluded from the study:

1. Inability to tolerate or complete PET/MR or PET/CT examinations (including, but not limited to, the inability to lie supine, claustrophobia, radiophobia, etc.);
2. Presence of other comorbidities, such as acute systemic illnesses and electrolyte imbalances;
3. Known allergy or hypersensitivity to the LRRC15 radiotracer or its synthetic excipients; fasting blood glucose level exceeding 11.0 mmol/L prior to [¹⁸F]FDG injection;
4. Patients deemed by the investigator to have poor expected compliance;
5. Pregnant or lactating (nursing) women;
6. Presence of any other conditions or factors that, in the opinion of the investigator, would make the subject unsuitable for participation in this trial.

Patients with clinically suspected or confirmed malignancies-such as pancreatic cancer, breast cancer, lung cancer, sarcoma, head and neck tumors, glioblastoma, colorectal cancer, and melanoma (supported by evidence including serum tumor markers, ultrasound, CT, MRI, and tissue histopathological examinations)-who are in good general condition.