Abstract:

Objective To analyse the influential factors for efficacy of radioiodine (¹³¹I) thyroid remnant ablation for differentiated thyroid carcinoma (DTC) after operation. Methods The clinical data of patients undergoing ¹³¹I thyroid remnant ablation after operation for DTC were collected. Binary Logistic regression analysis and chi-square test were employed to analyse the effects of gender, age, pathologic type, metastasis, volume of thyroid remnant tissues, serum thyroidstimulating hormone (TSH) level, rate of thyroid iodine uptake and ¹³¹I ablative dose on efficacy of thyroid remnant ablation. Results The clinical data of 183 patients were collected, among whom 109 (59.56%) achieved successful thyroid remnant ablation at first dose. Binary Logistic regression analysis indicated that the volume of thyroid residue and ablative dose of ¹³¹I were the main factors for the efficacy of ablation (Wald=8.59, P=0.003; Wald=6.40, P=0.011). Chi-square test revealed that the ablation efficacy in patients with TSH≥30 μIU/mL was higher than that in those with TSH<30 μIU/mL (χ²=7.291, P=0.007), while there was no significant difference between patients with TSH<60 μIU/mL and those with TSH≥60 μIU/mL (P>0.05). Conclusion The volume of thyroid residue and ablative dose are the main factors for the efficacy of ¹³¹I thyroid ablation for DTC. Patients with serum TSH≥30 μIU/mL may have favourable efficacy in thyroid ablation, while excessive serum TSH level may not yield better result.

Key words: differentiated thyroid carcinoma, radioiodine, thyroid remnant ablation, thyroid residue, therapeutic dose