Comparative Efficacy of Low- and High-Activity Radioactive Iodine Adjuvant Therapy in Intermediate-Risk Differentiated Thyroid Cancer: A Retrospective Cohort Study

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

TCTR

Registry ID

TCTR20260313002

Enrollment

130

Registered

2026-03-13

Start date

2005-09-01

Completion date

Unknown

Last updated

2026-04-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Intermediate risk thyroid cancer patients receiving radioactive iodine Differentiated thyroid cancer, Radioactive iodine, Intermediate-risk, Low-dose RAI, High-dose RAI, Treatment response

Interventions

Radioactive iodine 30 mCi for adjuvant therapy for intermediate-risk thyroid cancer patients.,Radioactive iodine 100-150 mCi for adjuvant therapy for intermediate-risk thyroid cancer patients.

Experimental Radiation,Active Comparator Radiation

Low-dose RAI,High-dose RAI

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Inclusion criteria

Inclusion criteria: 1. Histologically confirmed PTC or FTC (any variant), 2. ATA 2025 intermediate-risk classification, 3. Total thyroidectomy performed as primary surgical treatment, with or without neck dissection, 4. Adjuvant I-131 administered within 6 months post-surgery at either low-dose 30 mCi, or high-dose 100-150 mCi, 5. Complete 6-month follow-up data available, including serum TSH, Tg, and TgAb, and neck ultrasound.

Exclusion criteria

Exclusion criteria: 1. Distant metastases (M1 disease) identified at diagnosis or prior to RAI administration, 2. Prior RAI therapy for any indication, 3. Incomplete thyroidectomy (thyroid lobectomy or subtotal thyroidectomy), 4. Active concurrent malignancy at time of RAI, 5. Current immunosuppressive therapy at the time of RAI, 6. Missing primary outcome data at 6 months (absence of serum Tg, TgAb, or neck ultrasound result), 7. Pregnancy at the time of RAI administration.

Design outcomes

Primary

Measure	Time frame
Structural recurrence Last follow-up Ultrasound or Computed Tomography of the neck with fine needle aspiration, Radioactive iodine whole body scan, Surgical pathology	—

Secondary

Measure	Time frame
Biochemically Incomplete Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody,Structurally Incomplete Response Rate 6 months Neck ultrasound,Indeterminate Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody + Neck ultrasound,Thyroglogloblulin Antibody Trend 6 months Serum Thyroglogloblulin Antibody,Predictors of Excellent Response 6 months Logistic regression model,Excellent Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody + Neck ultrasound	—

Measure

Time frame

Biochemically Incomplete Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody,Structurally Incomplete Response Rate 6 months Neck ultrasound,Indeterminate Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody + Neck ultrasound,Thyroglogloblulin Antibody Trend 6 months Serum Thyroglogloblulin Antibody,Predictors of Excellent Response 6 months Logistic regression model,Excellent Response Rate 6 months Serum Thyroglogloblulin, Thyroglogloblulin Antibody + Neck ultrasound

—

Countries

Thailand

Contacts

Public ContactWasit Kanokwongnuwat

Phrapokklao Hospital

wasitov@gmail.com039319666

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: May 1, 2026