Radioactive Iodine as a Single-Modality Treatment in a Tumor Thrombus Arising from Follicular Thyroid Carcinoma

On rare occasions, differentiated thyroid carcinoma causes tumor thrombosis in the great veins. Multimodality treatment with surgery, radioiodine therapy, and targeted therapies is used to manage tumor thrombosis associated with thyroid malignancies, though no established guidelines exist. We present a woman with a tracer-avid tumor thrombus in the right brachiocephalic vein after surgery for follicular thyroid carcinoma. Follow-up revealed an excellent response after treatment with ¹³¹I as a single modality for both remnant and tumor thrombus.