No thyroid abnormalities in patients submitted to cardiac catheterization in the first eighteen months of life

No data are available about the risk of thyroid disturbance after exposure to low-dose radiation due to the use of cardiac catheterization in the first years of life.

To determine the risk of functional and morphological thyroid abnormalities in a homogeneous cohort of patients who underwent diagnostic low-dose radiation for heart catheterization during the first 18 months of life.

Fifty-five patients, submitted to cardiac catheterization during the first 18 months of life, underwent evaluation of the thyroid function and structure after a median period of 13 yr since the first radiation exposure. Sixty-eight unexposed controls matched for age and sex, underwent the same protocol. Twenty-two patients were then re-evaluated after a median period of 22 yr.

Thyroid function resulted normal in both patients and controls. The prevalence of small thyroid nodules and inhomogeneous structures in ultrasound study was not augmented in irradiated patients compared to controls. No thyroid tumors or reduced thyroid volume were observed.

Neither functional nor morphological disorders of the thyroid gland were demonstrated after a period up to 24 yr in patients exposed to diagnostic ionizing radiation for cardiac catheterization during the first 18 months of life.