Pathologie thyroïdienne morphologique radio-induite par de faibles doses d'irradiation cervicale : apport d'une enquête épidémiologique de cohorte.

Abstract

Thyroid morphological exploration was carried out on 396 patients who were recalled because their thyroid gland had been exposed during angiomas irradiation in childhood 11-43 years before (median, 22 years). Among these were 24 patients with a simple goiter and 13 patients with a single thyroid nodule. The irradiations have been classified in two categories based on their duration : short duration, from a few seconds to a few minutes (Sr-90, Xrays) and long duration (Ra-226, P-32, Y-90), from 30 minutes to several hours. The risk of a thyroid nodule increased significantly with the total dose received by the thyroid ; it was linked to the dose delivered in the short duration but not to that delivered in the long duration. The risk of a goiter, which also increased with the dose received by the thyroid, did not depend on the duration of the irradiation. This study emphasizes the role of the dose rate in the risk of thyroid nodule.