[N] How should GD be managed in children and adolescents?

[N1] General approach

    Children with GD should be treated with methimazole, 131I therapy, or thyroidectomy. 131I therapy should be avoided in very young children (<5 years). 131I therapy in patients between 5 and 10 years of age is acceptable if the calculated 131I administered activity is <10 mCi. 131I therapy in patients older than 10 years of age is acceptable if the activity is >150 µCi/g of thyroid tissue. Thyroidectomy should be chosen when definitive therapy is required, the child is too young for 131I, and surgery can be performed by a high-volume thyroid surgeon. 1/++0

The treatment of pediatric patients with GD varies considerably among institutions and practitioners. It is important to recognize that lasting remission after ATD therapy occurs in only a small minority of pediatric patients with GD, including children treated with ATDs for many years. In determining the initial treatment approach, the patient’s age, clinical status, and likelihood of remission should be considered.

Because some children will go into remission, MMI therapy for 1–2 years is still considered first-line treatment for most children. However, the majority of pediatric patients with GD will eventually require either radioactive iodine or surgery. When ATDs are used in children, only MMI should be used, except in exceptional circumstances. If clinical characteristics suggest a low chance of remission at initial presentation, MMI, 131I, or surgery may be considered initially. If remission is not achieved after a course of therapy with ATDs, 131I or surgery should be considered. Alternatively, MMI therapy may be continued until the child is considered old enough for surgery or radioactive iodine.

Properly administered, radioactive iodine is an effective treatment for GD in the pediatric population (187–189). 131I is widely used in children, but still viewed as controversial by some practitioners owing primarily to concern over cancer risks (190). Although there are sparse clinical data relating to radioactive iodine use in children with GD and subsequent thyroid cancer (191), it is known that risks of thyroid cancer after external irradiation are highest in children <5 years of age, and they decline with advancing age (192,193); see discussion of 131I therapy and cancer risk in [P3] below. In comparison, activities of radioactive iodine used with contemporary therapy are not known to be associated with an increased risk of thyroid neoplasm in children.

Thyroidectomy is an effective treatment for GD, but is associated with a higher complication rate in children than adults (194,195). Thyroidectomy should be performed in those children who are too young for radioactive iodine, provided that surgery can be performed by a high-volume thyroid surgeon, preferably with experience in conducting thyroidectomies in children.

Technical remarks: There may be circumstances in which 131I therapy is indicated in very young children, such as when a child has developed a reaction to ATDs, proper surgical expertise is not available, or the patient is not a suitable surgical candidate.