Premium
Radioiodine therapy of Graves' hyperthyroidism: standard vs. calculated 131 iodine activity *. Results from a prospective, randomized, multicentre study
Author(s) -
PETERS H.,
FISCHER C.,
BOGNER U.,
REINERS C.,
SCHLEUSENER H.
Publication year - 1995
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1995.tb01547.x
Subject(s) - radioiodine therapy , medicine , iodine , radioactive iodine , randomized controlled trial , graves' disease , nuclear medicine , prospective cohort study , radiochemistry , thyroid , thyroid cancer , chemistry , organic chemistry
. The present prospective, randomized, multicentre study was performed to directly compare for the first time the effectiveness of a standard activity of 555 MBq 131 iodine vs. an activity calculated to deliver 100 Gy for treatment of Graves' thyro‐toxicosis. Therapeutic success was defined as the elimination of hyperthyroidism 6 months after radio‐iodine application (range 4.5–8 months). A success rate of more than 90% in eliminating hyperthyroidism was reported for both approaches, but only in retrospective investigations. Investigated prospec‐tively, hyperthyroidism was eliminated in only 71% of the patients receiving standard activity (70/98) and 58% of those randomized for calculated activity (62/107). In the patients with standard activity, therapeutic success was inversely related to thyroid size. The rate was 100% for thyroid volumes ≤15 mL, 95% for 16–30 mL, 68% for 31–45 mL, 44% for 46–50 mL, 20% for 61–75 mL and 25% for ≥75 mL. In those patients with an activity calculated to deliver 100 Gy (except in those with a volume ≥15 mL) this size/outcome dependency was almost compensated. The rates were 86%, 65%, 45%, 61%, 41% and 45%, respectively. Furthermore, detailed statistical analysis revealed a strong correlation between the success of therapy and the radiation dose actually absorbed by the thyroid. The rate was 11 % for a target dose of 50Gy, 50% for 100 Gy, 67% for 150Gy, 80 % for 200 Gy, 84 % for 250 Gy, 88 % for 300 Gy, 90 % for 350 Gy and 93% for 400 Gy. Based on the results obtained in the present study, we strongly recommend individual calculation of the 131 iodine activity to be administered for treatment of Graves' hyperthyroidism. However, the target dose should be in the range of 200Gy.