Patients exposed to diagnostic head and neck radiation for the management of shunted hydrocephalus have a significant risk of developing thyroid nodules.

PURPOSE: External radiation to the head and neck can lead to an increased incidence of thyroid nodules. We investigated whether patients requiring repeated head and neck imaging for the management of shunted hydrocephalus had a higher incidence of ultrasound-detected thyroid nodules compared to reports of comparable age. METHODS: Patients treated at our institution for shunted hydrocephalus from 1990 to 2003 were contacted. Enroled patients underwent a thyroid ultrasound. Demographic data and radiation exposure history were obtained retrospectively. RESULTS: Thyroid nodules were identified sonographically in 15/112 patients (13.6 %). Patients with thyroid nodules were older (mean 24.3 ± 7.6 years) than those without (mean 18.4 ± 8.0 years) (p = 0.005). Those with a detectable thyroid nodule had a longer follow up time compared to those who did not (mean 21.9 ± 5.5 vs. 15.1 ± 7 years, respectively) (p = 0.018). CONCLUSION: Patients with shunted hydrocephalus are exposed to substantial head and neck radiation from diagnostic imaging and have a higher incidence of thyroid nodules detected by ultrasonography. These patients should be provided ongoing surveillance for detection of thyroid nodules and the possibility of malignancy.