Papillary thyroid cancer (PTC) is a type of thyroid cancer common in kids, especially girls. Scientists are studying how new targeted drugs affect the cancer's ability to take up radioactive iodine (RAI), which is often used in treatment. This study checks how well the cancer responds to these drugs over time. Patients with metastatic differentiated thyroid cancer (DTC) that has spread to the lungs may join the study. They will receive oncogene-specific targeted therapy—special drugs that target specific cancer genes—for about 4 weeks. Doctors will then scan their whole body to see changes in RAI uptake. This study does not involve new treatments, and decisions will be up to the doctors or other trials. To join, you must meet certain criteria, like having specific gene changes or being a part of other related trials.

• Study involves approximately 4-week treatment before a whole body scan.
• No new treatments; decisions are made by your doctor or another trial.
• Pregnant women and those who need sedation for scans cannot participate.