Ultrasound Screening for Thyroid Carcinoma in Childhood Cancer Survivors: A Case Series

Abstract

Context: Childhood cancer survivors need regular monitoring into young adulthood and beyond, because they are at risk for developing late-onset complications of cancer therapy, including second malignancies. Objective: This study focuses on the use of thyroid ultrasound to screen for thyroid carcinoma in a population of childhood cancer survivors. Patients: A total of 129 subjects who had received radiotherapy to the head, neck, or upper thorax for a pediatric cancer were studied in the setting of a long-term follow-up unit. Design: Thyroid ultrasound usually began 5 yr after radiotherapy and was repeated every third year, if negative. Median follow-up time since childhood cancer diagnosis was 15.8 yr (range 6.1–34.8 yr). Solid thyroid nodules were found in 35 patients. Fine-needle aspiration was performed in 19 patients, of which 14 had nodules above 1 cm. Main Outcome Measure: The main outcome measure was the finding of not palpable thyroid cancers. Results: Cytological examination of specimens diagnosed papillary carcinoma in five patients who underwent surgery. The cytological diagnosis of papillary thyroid carcinoma was confirmed in all cases by histological examination. Notably, only two of these patients had palpable nodules; the other three were smaller than 1 cm and were detected only by ultrasound. However, histological examination showed nodal metastases in two of these. Conclusions: Although ultrasound screening for thyroid cancer in the general population is not cost effective and could lead to unnecessary surgery, due to false positives, we believe that in childhood cancer survivors who received radiotherapy involving the head, neck, or upper thorax, it would be worthwhile.