Follow up of alterations in thyroid hormones and thyrotropin in patients of Hodgkin's disease given mantle radiation.

Thirty five patients with Hodgkin's disease who had received mantle radiotherapy to the neck were investigated for thyroid dysfunction serially over many years post radiation. No incidence of clinical hypothyroidism was noted; however, biochemical hypothyroidism (raised TSH, normal T3 and T4) was seen at some time during follow up in 22 patients. Thirteen had high TSH values at the first post radiation examination: in 6 they remained high during follow up and in seven they fell to normal or near normal without thyroxine substitution at any time. TSH abnormalities were seen by 2-3 years post radiotherapy and the return to normal, when it occurred, was seen by 4-6 years. It is advisable to follow up patients with abnormal TSH values following mantle radiation for a further 2-3 years and begin thyroxine substitution only if TSH abnormalities persist.