PROGNOSTIC VALUE OF EARLY DETERMINATION OF THYROIDAL RADIOIODINE UPTAKE FOLLOWING I131THERAPY

Abstract

With the aid of I132 (half-life, 2.3 hours) the thyroidal radioiodine uptake was measured in 41 cases of hyperthyroidism soon after I131 therapy, without delivering large doses of radiation to the thyroid gland. The prognostic value of a thyroidal uptake test soon after I131 therapy is very limited. It is unlikely that the patient will be cured unless the uptake has decreased three weeks after the treatment, though depression of the uptake at that time was observed even in a large proportion of cases that later required more therapy. In patients requiring retreatment, the uptake, if depressed, showed a tendency to recover between three weeks and two months after therapy. In most cases of remission there was a tendency toward further reduction of the thyroidal radioiodine uptake between three weeks and two months after I131 treatment.