Morgan TM, et al. - This trial was pursued with intention of outlining the thyroid dosimetry and long-term follow-up of childhood cancer survivors treated with whole lung irradiation (WLI), for Wilms tumor. For stage IV Wilms tumor patients, the average mean dose to the thyroid gland was determined as 6.7 Gy. The thyroid dysfunction exhibited a low rate, with a limited follow-up. Mitigation of the risks of long-term thyroid effects could be possible by emphasizing on blocking the thyroid gland as much as possible, while designing radiation fields.