Initial activity-related long-term outcome of iodine-131 treatment for thyroidectomy patients with differentiated...

To determine the outcome of iodine-131 (¹³¹I) treatment regimens in thyroidectomy patients with differentiated thyroid cancer.

Based on Taiwan's National Health Insurance Research Database (NHIRD) during the period from January 1, 2000 to December 31, 2010, 390 patients with well-differentiated thyroid cancer who underwent ¹³¹I treatment after thyroidectomy were enrolled in this study. Patients were classified into six groups according to the type of thyroidectomy and initial activity regimen of ¹³¹I treatment. The clinical outcome of ¹³¹I treatment was evaluated by total treatment number and medical expenditure, including costs for hospitalization and laboratory tests together with initial and subsequent ¹³¹I treatments. Multiple linear regression analysis was applied to analyze the factor(s) significantly affecting the outcome of ¹³¹I treatment.

Increased activity of the initial ¹³¹I regimen reduced the total treatment number significantly for unilateral total thyroidectomy with initial 100-150mCi ¹³¹I, and mildly for bilateral total thyroidectomy with initial 100-150mCi ¹³¹I and radical thyroidectomy with initial 30-99mCi ¹³¹I. Increased activity of the initial ¹³¹I regimen reduced total medical expenditure significantly for unilateral, and mildly for bilateral total thyroidectomy both with initial 30-99mCi ¹³¹I.

For patients with specific thyroidectomy for differentiated thyroid cancer, a high initial regimen of ¹³¹I treatment is more effective than the low activity regimen. An increased activity of the initial ¹³¹I regimen significantly reduced the total treatment number and medical expenditure.