Peiman Haddad - Department of Radiation Oncology, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran

  Radioiodine (۱-۱۳۱) is the treatment of choice in differentiated thyroid carcinoma. External radiotlierapy however, has it's own roie in these tumors. Treatment of anaplastic thyroid carcinoma ۱ms not acliieved any notahle success yet, though combined - modality regimens of radiotherapy and chemotherapy have sometimes shown significant results. In this paper the role of radiotlierapy and chemotherapy in differentiated and anaplastic thyroid carcinoma and also thyroid medullary carcinoma and lymphoma is reviewed.