Treatment Related Hypothyroidism, a Viewpoint from Cancer Therapy and Hematopoietic Stem Cell Transplantation

Hypothyroidism is the most common disorder of thyroid dysfunction. Sometimes, it can be caused by a variety of medical treatments that leads to a decrease in thyroidal production and secretion of thyroxine and triiodothyronine. Radiation treatment, either radioactive iodine treatment of hyperthyroidism or external radiation treatment for cancer therapy is a major cause of treatment related hypothyroidism. Others include various drugs associated with thyroid suppression, include lithium, iodine, iodine-containing drugs, radiographic contrast agents and cytotoxic chemotherapy. Thyroid dysfunction is one of the most common complications in endocrine system after hematological stem cell transplantation. This chapter will discuss certain type of primary hypothyroidism, including those encountered commonly in clinical practice, such as radioactive iodine therapy, tyrosine kinase inhibitor, hematological stem cell transplantation or other entities.