The Dose of Radioactive Iodine Needed to Ablate the Thyroid Remnant Left Behind After Thyroidectomy - Full Text View

Purpose

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.

Condition	Intervention	Phase
Thyroid Neoplasms	Drug: Radioactive iodine	Phase 3


Study Type:	Interventional
Study Design:	Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Parallel Assignment Masking: Open Label Primary Purpose: Treatment
Official Title:	Effect of the Radioiodine Dose in Thyroid Ablation- A Randomized Comparison of 1110 MBq to 3700 MBq

Resource links provided by NLM:

MedlinePlus related topics: Thyroid Cancer Thyroid Diseases

Drug Information available for: Iodine

U.S. FDA Resources

Further study details as provided by Helsinki University:

Primary Outcome Measures:

Cumulative number of radioactive iodine administrations [ Time Frame: 15 yrs ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:

Adverse events [ Time Frame: 15 yrs ] [ Designated as safety issue: Yes ]
Absorbed radiation dose [ Time Frame: 15 yrs ] [ Designated as safety issue: Yes ]
Cancer recurrence [ Time Frame: 15 yrs ] [ Designated as safety issue: Yes ]


Enrollment:	160
Study Start Date:	January 2000
Estimated Study Completion Date:	September 2020
Primary Completion Date:	October 2004 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Experimental: Radioactive iodine 1,1 GBq Low activity of radioiodine, 1,1 GBq	Drug: Radioactive iodine Radioiodine is radionuclear treatment given in oral capsules in two activies 1,1 and 3,7 GBq Other Name: radioiodine
Radioactive iodine 3,7 GBq Routine activity of radioiodine, 3,7 GBq	Drug: Radioactive iodine Radioiodine is radionuclear treatment given in oral capsules in two activies 1,1 and 3,7 GBq Other Name: radioiodine

Detailed Description:

The study participants are randomly allocated to receive either a 1110 MBq or a 3700 MBq dose of radioiodine (131I) approximately 5 weeks after thyroidectomy. Thyroxin substitution is initiated only after administration of radioactive iodine. Treatment efficacy is monitored using serum thyroglobulin measurements and whole body radioiodine scanning. The absorbed radiation dose at the thyroid remnant and the biological half-life of radioactive iodine are measured with SPECT, 131I iodine detector and a Geiger counter.

Treatment related adverse events are collected using structured forms 4 to 5 days, 2 weeks and 3 months after administration of radioiodine. The need for a repeat treatment is assessed 4 to 6 months after the first administration of radioiodine. The criteria for a repeat radioiodine treatment are serum thyroglobulin > 1 ug/L and/or presence of abnormal radioiodine uptake in a whole body radioiodine scanning, which is carried out following a 4-week interruption of thyroxin supplementation or following administration of rhTSH.

Number of patients: 160

Aims of the study:

To find out weather the risk for second radioiodine treatment differs with two dose levels of radioiodine: 1110 MBq or 3700 MBq.
To study possible differences in the adverse effects in the treatment groups. Also days at hospital are counted.
To analyse the effect of absorbed radiation dose to the treatment results

Eligibility


Ages Eligible for Study:	18 Years and older (Adult, Senior)
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	No

Criteria

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

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00115895

Locations


Finland
Helsinki University Central Hospital, Department of Oncology
Helsinki, Finland, FIN-00029HUS

Sponsors and Collaborators

Helsinki University

Helsinki University Central Hospital

Investigators


Principal Investigator:	Hanna O Mäenpää, M.D. Ph.D.	Deputy Chief Physician

More Information

Additional Information:

Helsinki University Central Hospital This link exits the ClinicalTrials.gov site

Publications:

Roos 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. Review.

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Mäenpää 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.


Responsible Party:	Hanna Mäenpää, Chief of Department, Helsinki University
ClinicalTrials.gov Identifier:	NCT00115895 History of Changes
Other Study ID Numbers:	SYTJ001T/2000
Study First Received:	June 26, 2005
Last Updated:	March 18, 2016
Health Authority:	Finland: Ethics Committee

Keywords provided by Helsinki University:


radioiodine serum thyroglobulin whole body radioiodine scanning

Additional relevant MeSH terms:


Thyroid Diseases Thyroid Neoplasms Endocrine System Diseases Endocrine Gland Neoplasms Neoplasms by Site Neoplasms Head and Neck Neoplasms Iodine	Cadexomer iodine Anti-Infective Agents, Local Anti-Infective Agents Trace Elements Micronutrients Growth Substances Physiological Effects of Drugs

ClinicalTrials.gov processed this record on September 26, 2016