Clinical trial · Interventional
The Dose of Radioactive Iodine Needed to Ablate the Thyroid Remnant Left Behind After Thyroidectomy
Effect of the Radioiodine Dose in Thyroid Ablation- A Randomized Comparison of 1110 MBq to 3700 MBq
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
The thyroid cells take up iodine, and radioactive iodine is commonly used to irradiate residual thyroid tissue and thyroid cancer following surgical removal of the thyroid gland (thyroidectomy). A whole body radioactive iodine scanning is usually carried out after thyroidectomy to assess the amount of thyroid tissue left behind at surgery (that might still contain cancer), and to evaluate the presence of iodine avid lesions elsewhere in the body (that might be cancer metastases). A large dose of radioactive iodine is often given, still the optimal iodine dose to ablate the thyroid remnant after surgery is not known. In this study, two radioactive iodine doses are compared in the ablation of the thyroid remnant, a smaller (1110 MBq) dose and a larger (3700 MBq) dose. The study participants are randomly allocated using a 1:1 ratio to receive either the smaller or the larger radioactive iodine dose. These treatments are compared for safety, adverse effects, and the need for subsequent repeat treatments. The individual absorbed radiation doses are measured. The study hypothesis is that fewer repeat radioiodine treatments might be needed after the larger dose, but the larger dose might be associated with a higher frequency of adverse events.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Thyroid Neoplasms | Thyroid Gland Neoplasm | ALIAS | 0.90 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Radioactive iodine | Drug | Radioactive Iodine | ALIAS |
Design
Arms and outcomes
Arms (2)
- type
- EXPERIMENTAL
- label
- Radioactive iodine 1,1 GBq
- description
- Low activity of radioiodine, 1,1 GBq
- interventionNames
- Drug: Radioactive iodine
- type
- OTHER
- label
- Radioactive iodine 3,7 GBq
- description
- Routine activity of radioiodine, 3,7 GBq
- interventionNames
- Drug: Radioactive iodine
Primary outcomes (1)
- measure
- Cumulative number of radioactive iodine administrations
- timeFrame
- 15 yrs
Secondary outcomes (3)
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion criteria: * Total or near total thyroidectomy performed for papillary or follicular thyroid cancer * R0-1 resection, no macroscopic cancer left behind at surgery * Physically and emotionally able to undergo radioiodine treatment * A written informed consent Exclusion criteria: * Pregnancy * Physical or psychiatric illness that may deteriorate during the isolation period required by radioiodine therapy
References
Publications (2)
- BACKGROUNDRoos DE, Smith JG. Randomized trials on radioactive iodine ablation of thyroid remnants for thyroid carcinoma--a critique. Int J Radiat Oncol Biol Phys. 1999 Jun 1;44(3):493-5. PMID 10348276
- DERIVEDMaenpaa HO, Heikkonen J, Vaalavirta L, Tenhunen M, Joensuu H. Low vs. high radioiodine activity to ablate the thyroid after thyroidectomy for cancer: a randomized study. PLoS One. 2008 Apr 2;3(4):e1885. doi: 10.1371/journal.pone.0001885. PMID 18382668