UFFicrs of L321 paDrIAviond CN THE 'THYnoID or vowesee. CLEMCAL SUDJECTS WIGH IYPERTHYROIDICN — “he description o: this work continued ea 2 pravicusly deceriied. (Thp follcwing ‘wo paracranhs are reprodu‘ced from “che previcus annual report With only slight ravision besnuse the bLusic outline for the collection of thee data reir basically we: sams.) Vory titallec Cats continue: to Le collected on celected patients typate with 23] foo hyperthyroiudiisa co that che ultinate clinical e*facts can le relited "o the Lenavior of lott tat was opserved in that individua2 - after the treatment was Given. This is cone in_an effort to get a bett cs earchLtasg of why the effect of a yiven dese of 2425 per estinated fram o thyroid LAULo Lo Vatialle anon indaviduass. a spite of ‘therapeutic dose whicn are calculated to Le just sufficient to bring the hyrerthyroidism under ontrol, we Still observe far too high an incidence of_hypothyroidism, not weeks months , but years after the radiation is: delivered. Since the responsible investigatcr is in charze of all 131] therapy in this hespital, there is an opportunity study selected patients in mpreat detail. The following observations to mace : 1.) Careful pretreatment characterization of the glad and the patipnt, not only «ixrh respect to the uptake of a tracer of 131t, but a yarLety of observations cn factors that may explain differences among patients. 2.) Determinaticn of the wnount cf the treatment dose taken up by the thyroid, folleved ky alzost daily measurements over the gland thereafter to determine the disappearance curve of the isotope from the glfnd. 36) Multiple observations on the concentration of 131I in ine seruq and the excretion in the urine as they relate to the thyroid at given S. 4.) Determination of the extractable end non-extractable fractions the blood (butanol) and in some cases the serial quantitative deterfnination of iodinated compounds in the serum as the radiation effect takes place. 5S.) Similar observations are made on the total urinary excretion of i3ir for several days and in some cases determination of the compourfs appearing there. As Chairman of the Steering Committee for the Cooperative Thyroto sis Therapy Follow-up Study of the National Center for Radiological Health the USPHS, the principal investigator has devoted much time to analyzing the data dh the results of radioiodine therapy from 19 centers participating in this large study. Although the patients studied in our laboratory represent a relatively grmall fracticn of the total included in this large study of over 38,000 patients, half Pf which were treated with 1311, the data on many of our individual patients has proven to be the most complete among, the various leboratcries. Our data consists of 4 curve cr the therarpeutiic dose from the th:rcid, the chenges in the total] amount of raciioactivity in the serum, the changes i: various iodinated compounds i at intervals of hours, days, and weeks af. therapy, and the excretion Pf iodine in the urine. It has been thought that suc’ .- a could be the basis from which to devise and test models that would reflect the nature and the extent of effect on the thyroid. It has been hoped by the Steering Committee that} it might be possible to utilize the detailed data from individual patients (Cacqui this contract) in kinetic models. such as those of Berman, to discover gpne