Reduced thyroid volume and hypothyroidism in survivors of childhood cancer treated with radiotherapy.
OBJECTIVE
Children treated for cancer may have sequelae due to the treatment. The aim of this study was to assess the frequency of hypothyroidism and the thyroid volume of patients treated with radiotherapy for cancer during childhood.


METHODS
Fifty-nine patients treated with external beam radiation to different areas of the body during childhood.


METHODS
Cross-sectional study of patients assessed for late effects of external beam radiation treatment for childhood cancer. General and anthropometric characteristics, time from radiotherapy, family history of thyroid dysfunction, radiotherapy report, thyroid function tests, antithyroperoxidase antibodies and thyroid ultrasound were analyzed.


RESULTS
Hypothyroidism was found in 23 (39%) patients, 3.5 +/- 1.9 years after radiotherapy carried out at the mean age of 7.6 +/- 3.4 years. Site of irradiation had the greatest association with hypothyroidism. Anti-thyroperoxidase antibodies were normal in all patients. Thyroid volume was significantly lower in irradiated patients with hypothyroidism than in those with normal thyroid function (p <0.001).


CONCLUSIONS
Hypothyroidism is very common in survivors of childhood cancer treated with external beam radiation. Primary thyroid damage is suggested because of the smaller thyroid volume.
Bonato
Cassiane
C
Endocrinology Division, Hospital de Clinicas de Porto Alegre, Brazil.
Severino
Romulo França
RF
Elnecave
Regina Helena
RH
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009369:Neoplasms / Q000532:radiotherapy*; D009929:Organ Size / Q000528:radiation effects; D015995:Prevalence; D011832:Radiation Injuries / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D018714:Radiotherapy, Adjuvant; D011882:Radiotherapy, High-Energy / Q000009:adverse effects*; D013961:Thyroid Gland / Q000528:radiation effects*; D013972:Thyrotropin / Q000097:blood; D055815:Young Adult
D013972:Thyrotropin