Comparison of Iodine-124 (I-124) and Iodine-131 (I-131) Radiopharmacokinetics

The recruitment status of this study is unknown because the information has not been verified recently.
Verified August 2011 by Washington Hospital Center.
Recruitment status was  Recruiting
Genzyme, a Sanofi Company
Information provided by:
Washington Hospital Center Identifier:
First received: June 17, 2009
Last updated: August 15, 2011
Last verified: August 2011

This research study is to compare the radiopharmacokinetics of I-124 to the radiopharmacokinetics of I-131 in patients who have well-differentiated thyroid cancer after recombinant human thyroid-stimulating hormone (rhTSH) injection. I-131 is routinely used for imaging and dosimetry for patients with well-differentiated thyroid cancer. In this study, I-124 is administered orally in capsular form, and the radiopharmacokinetics of I-124 is compared with I-131. I-124 is another isotope of iodine, which is cyclotron-produced. I-124 has multiple advantages:

  • Ideal Half-Life (4.2 days) for delayed imaging.
  • High resolution tomographic imaging.
  • Feasibility of quantitating lesion uptake.
  • Potential of dosimetry for the planning of radioiodine therapy.

Voluntary patients will have I-124 dosimetry performed in addition to the I-131 dosimetry, which is planned as part of routine clinical care. I-124 dosimetry is composed of four parts: (1) two extra doses of injections of rhTSH, (2) the administration of I-124, (3) PET imaging, and (4) drawing blood samples.

Patients will receive two additional injections of rhTSH. This is similar to the procedure for I-131 dosimetry. Second, they will receive I-124. I-124 is similar to I-131 except I-124 decays in a different way to emit a positron so that the PET scanner can be used for imaging. I-124 is given in the form of one or several capsules, which are taken by mouth. This is also similar to I-131. Third, PET/CT imaging is done for approximately 30 minutes to one hour on five consecutive days. Radiation from PET/CT scan is far less than what they receive from a diagnostic CT scan. For the fourth part, a technologist will draw about 5 cc from the forearm on each of the five consecutive days. This is also similar to I-131.

Initially, all patients will be randomized to one of two study groups. The first group will have the I-131 dosimetry performed first followed by the I-124 dosimetry, and the second group will have the I-124 dosimetry performed first followed by the I-131 dosimetry.

The risk of this study is considered very low, and the potential benefits to the patient are considered very high.

Condition Intervention
Thyroid Cancer
Radiation: Radioactive Iodine 124

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Single Group Assignment
Masking: Open Label
Official Title: Comparison of I-124 and I-131 Radiopharmacokinetics in Patients Who Have Well-differentiated Thyroid Cancer and Are Prepared With Recombinant Human TSH Injection (rhTSH)

Resource links provided by NLM:

Further study details as provided by Washington Hospital Center:

Primary Outcome Measures:
  • Compare the measurement of radioiodine uptake and clearance in suspected metastatic foci of well-differentiated thyroid cancer [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Estimated Enrollment: 30
Study Start Date: December 2008
Estimated Study Completion Date: August 2012
Estimated Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Intervention Details:
    Radiation: Radioactive Iodine 124

    After TSH stimulation with Recombinant human TSH (rhTSH) for 2 days, a dose of radioactive iodine 124 ( I-124) 1.7 mCi is administrated orally and PET imaging is done for 5 continuous days including the day of the dose administration. On each day, just before imaging, 5 ml of blood is drawn.

    Patients will be randomized to either the sequence above (e.g. I-131 followed by I-124) or to the reverse sequence in which the I-124 is given first followed by the I-131. If I-124 is administered first and as long as the whole body retention is < 2% by the start of the second rhTSH stimulation, the I-124 will not interfere with the I-131.

    Other Name: Official name for I-124: "Sodium [124I] iodide solution in 0.02 N aqueous NaOH"
  Show Detailed Description


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • 18 years or older
  • Well-differentiated thyroid carcinoma
  • Referred for I-131 dosimetry
  • Preparation with Recombinant Human TSH (rh TSH)

Exclusion Criteria:

  • < 18 years of age
  • Pregnancy or breast feeding
  • Inability to comply with instructions
  • Simultaneous participation or participation in any other research study within the last month
  • A body weight greater than 350 lbs
  • A creatinine > 1.5 mg/ml for males and 1.4 mg/ml for females
  • Preparation with thyroid hormone withdrawal(THW)
  Contacts and Locations
Please refer to this study by its identifier: NCT00926978

Contact: Dougals Van Nostrand, MD 202 877 0348
Contact: Boris A Frolov, MD 202 877 6094

United States, District of Columbia
Washington Hospital Center Recruiting
Washington, District of Columbia, United States, 20010
Contact: Douglas Van Nostrand, MD    202-877-0348   
Contact: Boris A Frolov, MD    202 877 6094   
Sponsors and Collaborators
Washington Hospital Center
Genzyme, a Sanofi Company
Principal Investigator: Douglas Van Nostrand, MD Director, Nuclear Medicine
  More Information

No publications provided

Responsible Party: Douglas Van Nostrand, MD, Director, Division of Nuclear Medicine, Washington Hospital Center Identifier: NCT00926978     History of Changes
Other Study ID Numbers: 2008-292
Study First Received: June 17, 2009
Last Updated: August 15, 2011
Health Authority: United States: Institutional Review Board

Keywords provided by Washington Hospital Center:

Additional relevant MeSH terms:
Thyroid Neoplasms
Thyroid Diseases
Endocrine Gland Neoplasms
Neoplasms by Site
Head and Neck Neoplasms
Endocrine System Diseases
Cadexomer iodine
Anti-Infective Agents, Local
Anti-Infective Agents
Therapeutic Uses
Pharmacologic Actions
Trace Elements
Growth Substances
Physiological Effects of Drugs processed this record on April 17, 2014