[en] The authors describe the results of thyroid irradiation tests, which include the TRH test (TRH = thyroid stimulating hormone), and results are quoted on a group of 43 patients, of various ages. Details are included of the medication in each case. Other tests applied include E.C.G. tests, X-ray photographs, studies of the accumulation of antibodies near the thyroid, immuno-electrophoretic surveys and I-131 isotope pick-up by scanning of a radio-active tracer. The tracer activity is checked at intervals of 5, 24 and 48 hours. (G.C.)