Long-Term Outcome of Low- and High-Dose Radioiodine for Thyroid Remnant Ablation

Clin Endocrinol (Oxf). 2024 Dec;101(6):682-689. doi: 10.1111/cen.15134. Epub 2024 Sep 4.

Abstract

Objective: We conducted a prospective randomized clinical trial to compare the efficacy of low- and high-dose radioiodine for remnant ablation in patients with low-risk differentiated thyroid cancer (DTC) in China. The first-stage results showed equivalence was observed between the two groups. Here, we report recurrence and survival at 3-5 and 6-10 years and biochemical parameters.

Design, patients and methods: Between January 2013 and December 2014, adult patients with DTC were enroled. Patients had undergone total or near-total thyroidectomy, with or without cervical lymph node dissection, with tumour stages T1-T3 with or without lymph node metastasis, but without distant metastasis. Patients were randomly assigned to the low-dose (1850 MBq) or high-dose (3700 MBq) radioiodine group. They were then followed up for 3-5 and 6-10 years. Data on biochemical abnormalities, recurrence and survival were analysed using Kolmogorov-Smirnov and χ2 tests.

Results: The data of 228 patients (mean age = 42 years; 70.6% women) were analysed, with 117 patients in the low-dose group and 111 in the high-dose group. There were no significant differences in biochemical abnormalities, recurrence, or survival rates at the 6-10-year follow-up (all p > .05). Nine patients experienced recurrence in the low-dose group (8.7%), while eight patients experienced recurrence in the high-dose group (8.2%). The survival rates were 100% and 98.2% in the low- and high-dose groups, respectively.

Conclusions: The long-term effectiveness and safety of low-dose (1850 MBq) radioiodine are the same as those of high-dose (3700 MBq) radioiodine for thyroid remnant ablation in Chinese patients with low-risk DTC.

Keywords: China; prospective study; radioiodine; remnant ablation; thyroid cancer.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • China
  • Female
  • Humans
  • Iodine Radioisotopes* / administration & dosage
  • Iodine Radioisotopes* / therapeutic use
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local
  • Prospective Studies
  • Thyroid Gland / pathology
  • Thyroid Gland / radiation effects
  • Thyroid Gland / surgery
  • Thyroid Neoplasms* / pathology
  • Thyroid Neoplasms* / radiotherapy
  • Thyroid Neoplasms* / surgery
  • Thyroidectomy*
  • Treatment Outcome

Substances

  • Iodine Radioisotopes