Vandetanib trifluoroacetate is primarily used in the treatment of certain types of thyroid cancer, particularly medullary thyroid cancer that cannot be removed by surgery or has spread to other parts of the body. It works by inhibiting specific tyrosine kinases involved in the growth and spread of cancer cells. This targeted therapy helps to slow down or stop the progression of the disease, providing a therapeutic option for patients with advanced or metastatic conditions. It is typically administered orally, allowing for convenient patient use outside of clinical settings. Regular monitoring is essential to manage potential side effects, which can include skin reactions, gastrointestinal issues, and cardiovascular complications.