[Effectiveness of high-dosage radioiodine therapy in the elimination of remnant tissue following total thyroidectomy].

The efficacy of high doses of radioiodine for total ablation of functional remnants left behind after total surgical thyroidectomy for thyroid cancer decreases with the number of treatments as well with the course of therapy. Most effective are 500 mCi of 131I administered in 5 fractions within 3 years. Up to 1000 mCi of 131I delivered within 5 years are still powerful but much less so. All further treatments with high doses of radioiodine are only of diagnostic value for detection of functional metastases with low radioiodine uptake. In about 45% of all patients even excessively high doses of radioiodine failed to ablate all functional residual thyroid tissue.