Study of 177Lu-LNC1004 Injection in FAP-positive Radioiodine-refractory Differentiated Thyroid Cancer

This study is testing a new radioactive drug therapy called 177Lu-LNC1004 for people with thyroid cancer that has stopped responding to radioactive iodine treatment (a condition called radioiodine-refractory differentiated thyroid cancer, or RAIR-DTC). The drug targets a protein called FAP that is found on cancer cells, delivering radiation directly to the tumor. This is an early-phase study to assess safety and early signs of effectiveness. **You may be eligible if...** - You are 18 years or older - You have been diagnosed with differentiated thyroid cancer that no longer responds to radioactive iodine - You have already tried or refused standard targeted therapy (TKIs such as lenvatinib or sorafenib) - Your cancer shows FAP-positive lesions on a special PET/CT scan - You have at least one measurable tumor and adequate organ function - Your general health score (ECOG) is 0, 1, or 2 **You may NOT be eligible if...** - Your cancer does not show FAP-positive lesions on imaging - You have active brain metastases causing symptoms - You have severe kidney, liver, or bone marrow dysfunction - You are pregnant or breastfeeding - You have had recent radiation to major bones (such as more than 25% of the skeleton) Talk to your doctor to see if this trial is right for you.