Treatment of medullary carcinoma thyroid is
**Core Concept**
Medullary carcinoma of the thyroid (MCT) is a rare, malignant tumor of the thyroid gland that originates from parafollicular cells, also known as C-cells. The treatment of MCT involves a multidisciplinary approach, including surgery, radioactive iodine, and targeted therapy.
**Why the Correct Answer is Right**
The correct answer is **D. Vandetanib**. Vandetanib is a tyrosine kinase inhibitor that targets the RET and VEGFR pathways, which are involved in the pathogenesis of MCT. By inhibiting these pathways, Vandetanib helps to slow the growth of the tumor and reduce the risk of metastasis. In addition, Vandetanib has been shown to improve progression-free survival and overall survival in patients with MCT.
**Why Each Wrong Option is Incorrect**
**Option A:** Surgery is an important component of MCT treatment, but it is not the primary treatment for advanced or metastatic disease.
**Option B:** Radioactive iodine is not effective in treating MCT, as these tumors do not take up iodine.
**Option C:** Tyrosine kinase inhibitors such as Sorafenib and Sunitinib are not specifically approved for the treatment of MCT.
**Clinical Pearl / High-Yield Fact**
Vandetanib is a targeted therapy that has been specifically approved for the treatment of MCT, making it a valuable option for patients with this rare and aggressive tumor.
**Correct Answer:** D. Vandetanib