peo re 110 1AEA-SM-224/607 LARSEN ¢1 al. 707 lil and the PSE response to TRE was abso significandly mecrcased, midicating the presence of tmpalied thyroid Cunection. Chasacteristics of Marshallese with biochemical evidence of Uryroid dystunction 40 1 bn Table Vil are presented the results of other studies mi the lous indiveidials PL aSML TSH wus with biochemical evidence of inpuired thyroid fuaction. Al present, these are the only gidividuals who have fulliiled the crtena described in table V, though 30 7 several otlier subycets have shown al feast one abnormal tinding but have aod had the required number of tests lo meet the established criteria Vhhe age al vaposure Varied trom 16 to 38 years and the estimated thyroid dose was thought ti three Of four bo be less than 400 rads. Serum Fy concentrations ta all tour | subjects wie inthe low notimal range when Comsidercd in the light of (hear estimated serum Viytoxine- Banding Globulin CEBG)} Subjects 74 and 71 have approximately nomad serum TRG concentrations, whereas subjects 78 and 4 Jpparently have a modestly clevated serum TRG. ba the kasd columuiol Latie VIE are shown results of Uie TSH stimulation tests of these subjects performed in 1974 FIG) da all three, the scrum Ty response to USE was inpaired, suggesting decreased thyroid ivserve Basal pleasing TSH and TRH-stunuduted TSH tn euthyroul Marshallese and in four exposed subjects ol with bier hemuwal evidence of unpaired thyroid (NORMAL. HANGE BASAL function. DISCUSSION Plasma was ebtuined 20 ini uffer iitfusiwn of S00 py TRH AFTER TAH The upper lteits of the nurmal senge are indicated by the shaded bars. An association of thyfuid nodulanity and cancer with poror radiation of the thyroid gland, particuludy in younger patients, ts wedl recognized aud the dasuclulion hus recently been reviewed FEL) TABLE VIL CHARACTERISTICS OF MARSHALLESE WITH BIOCIIEMICAL EVIDENCE OF THYROID DYSFUNCTION Subject Age af ExXpusure Bstumated 5 thyroid dose (rads) Normal valucs t cums (g/dl) 5 10.2 of hy pothyruidion within one year and a 13% probalality in 3 years [13]. There are few dala avatlable in the titerature relative to the possibility of (pagfda) 1.10 16 Lhe luwest dosage considered in previous studies of (lis type has been approximately 3400 rads estimated dose to the Hayroid which was associated wath a 6% probability 244hp Tse units 0.85 with thytoid dysfunction is assocmicd wilh hypothyronlisay in a signidicau fraction of the patietits (as high as 50%) al the higher dosage levels [E22] Va laciement TaGl dn addition, do has been recognized that radiation tu the thyioid delivered in the Course of treatment of pulients hypothyroiisi following (dosages of dess Chan 2500 ads. Prelimanary results of Hamilton and Lhompkins indicated that eight of 443 subjects (1.8%) subse- 64 quently became ly pothyroid after diagnostic '2'P tests at less than 16 years [13] 74 ty 335 5.8 0.97 Os 71 28 345 52 0.98 N17 7a 3? 335 6.1 4 0.82 Us 34 With an estuaated thyloid absorbed dose of 30 rads developed hy pothy routs, but tice of 140 subjects receiving J) to 8G rads estimated thyroid dose had this 345 14 0.79 uy condition [14]. OF PST subsects with an estimated dose range of 81 * 810 A sumunary of these preliminary data has been presented None of 146 subjects , | 1900 rads, five hypothyroid patients were found with an iickence of hypothyr oidisin of O 25% yearly Not tested : . i t