Background: Anaplastic thyroid cancer has a very poor prognosis, especially in patients who have gross residual disease following resection.
Case report: We present the case of a patient with anaplastic thyroid cancer and a significant gross residual disease treated with intensity-modulated radiotherapy with concurrent chemotherapy and sunitinib who had a complete response and remains without evidence of disease more than 18 months after diagnosis.
Conclusion: Chemoradiotherapy has an important role in the adjuvant treatment of anaplastic thyroid cancer in selected patients and should be considered when gross residual disease is present following resection. The combined use of radiotherapy and targeted biological agents such as sunitinib may warrant further investigation.