Success rate of radioiodine treatment of hyperthyroidism in Qatari patients

Abstract EN

To evaluate the response rate of hyperthyroidism to radioactive iodine treatment (RAI) and the mortality rate post RAI treatment in a Qatari cohort the records were analyzed retrospectively of 113 hyperthyroid Qatari pa¬tients (23 male, 90 female) treated with RAI (1-131) in the Endocrine Clinic, Hamad Medical Corporation, between 1984 and 2002.

90 (79.6 %) had diffuse goiter, 14 (12.4%) multinodular goiter, 6 (53%) single nodular goiter and 3 (2.7 %) unknown etiology.

Follow up ranged from two to ten years with free thyroxin and thyroid stimulating hormone being recorded at diagnosis; six months and one year post RAI treatment and yearly thereafter.

The incidence of hypothyroidism was 64.4% after six months post RAI treatment and 75.9% at one year.

Euthy¬roid state was high inpatients who did not receive antithy¬roid drugs, whereas the hypothyroid state was higher in a group with pre-treatment antithyroid medication (80% versus 62.8%).

The euthyroid state was more in diffuse hyperthyroidism 22.4%, while 84.6% of multinodular goiter became hypothyroid after six months of RAI treat¬ment.

Mortality rate was not increased post RAI treatment as compared to general population.

Conclusion : The incidence of hypothyroidism was 75.9% at one-year post RAI treatment and the rate of hy¬pothyroidism increased with the length of follow up to 10 years (86.7%).

There was no linear relation in response rate to increasing doses of RAI treatment groups.