The treatment results of differentiated thyroid carcinoma post-thyroidectomy with 131I at Thai Nguyen oncology centre

SUMMARY

Objectives: 1.To evaluate treatment results of differentiated thyroid carcinoma patients post-thyroidectomy with 131I. 2. To study some factors related to treatment results.

Materials and method: A descriptive study was conducted on 87 diffentiated thyroid carcinoma patients treated at Thai Nguyen oncology centre from 2011 to 2018.

Results: Medial age of patients was 47.3 ± 12.7, female : male = 4.8 : 1. 67 % were papilliary thyroid carcinoma, 63.2 % had no metastases, 32.2 % had cervical nodal metastases, 4.6 % had distant metastases. 95.4 % of patients were in stage I, II, III. Post-operative thyroid remnants were 3.52 ± 1.73 g. The rates of patients responding completely after 1, 2, 3 and over 3 doses of 131I were 60.9 %, 79.3 %, 87.4 % and 92 % respectively. Medial total treatment dose of 131I used was 112.5 ± 31.2 mCi, medial treatment times were 1.83 ± 0.3 times. In patients with no distant metastases, the thyroid remnant ablation of 131I with doses from 30 to 50 mCi was as well as with dose of 100 mCi. The treatment results in patients under 45 years were better than in patients over 45 years, in patients with no metastases and cervical nodal metastases were better than in patients with distant metastases, in patients in stage I, II and III were better than in patients in stage IV, in patients with thyroid remnants < 2 g were better than in patients with those ≥ 2 g, in patients with serum Tg < 10 ng/dL or serum TgAb < 100 IU/mL were better than in patients with those ≥ 10 ng/dL or ≥ 100 IU/mL respectively.

Conclusion: The treatment effectiveness of 131I with low dose (30 – 50 mCi) was equivalent to high dose of 100 mCi in patients with no distant metastases. 60.9 % of patients had good results after only 1 dose of 131I. With medial dose of 112.5 ± 31.2 mCi of 131I, after 1.83 ± 0.3 treatment times, 92 % patients was responded completely\. Patients were younger than 45 years, patients with no distant metastases, in earlier stages of cancer, with less thyroid remnants, with lower levels of serum Tg or serum TgAb responded better than to the treatment.

Keywords: Differentiated Thyroid Carcinoma (DTC), 131I, Thyroglobulin (Tg), Anti Thyroglobulin (TgAb), Whole Body Scan (WBS).