Clinical outcomes and prognostic factors of radioiodine ablation therapy for lymph node metastases from papillary thyroid carcinoma

Objective A total of 118 patients with papillary thyroid carcinoma treated with radioactive iodine for lymph node metastases were analyzed retrospectively between August 2008 and June 2014. We describe the clinical course of these patients and focus on factors associated with lymph node metastases response to iodine-131 (131I) treatment. Patients and methods A total of 118 postoperative papillary thyroid carcinoma patients who underwent 131I treatment with lymph nodes as the only site of metastasis on whole-body scan (131I Rx-WBS) and single-photon emission computed tomography–computed tomography (SPECT-CT) were enrolled. Clinical and laboratory evaluations including 131I Rx-WBS, serum thyroglobulin level, and radiographic findings were carried out during follow-up. Results At the end of follow-up, the rates of complete remission and partial response were 28.0% (33/118) and 52.5% (62/118), respectively. An overall effective rate of 80.5% (95/118) was obtained after three times radioiodine therapy and administration of 3.7–16.7 GBq 131I. Conclusion Our data indicate that 131I therapy is highly effective in the treatment of lymph node metastases from papillary thyroid carcinoma; patients with a small size of metastatic lymph node, younger patients, those with lower thyroglobulin levels, and patients with lymph node metastases detectable on the first postablative 131I Rx-WBS and single-photon emission computed tomography–computed tomography showed a good response to radioiodine ablation therapy.