18F Labeled FAP Targeted Molecular Probe in Early Tumor Diagnosis

This study is testing a new PET scan imaging agent that targets a protein called FAP (fibroblast activation protein), which is found in many tumors. The goal is to see if this radioactive probe can detect cancers earlier and more accurately than standard CT or MRI scans. **You may be eligible if...** - You are between 18 and 75 years old - A CT or MRI scan has already detected a tumor in your body - You have been diagnosed with lung cancer, thyroid cancer, pancreatic cancer, melanoma, or a neuroendocrine tumor - Your kidneys, liver, and blood counts are within acceptable ranges **You may NOT be eligible if...** - You have a known allergy to similar imaging agents - You are currently participating in another drug clinical trial - You have HIV, active hepatitis B or C, or other serious chronic infections - You have significant abnormalities in liver or kidney function - Your blood counts are too low Talk to your doctor to see if this trial is right for you.