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Comparison of Iodine-124 (I-124) and Iodine-131 (I-131) Radiopharmacokinetics in Patients Prepared With Recombinant Human TSH Injection (rhTSH)

NCT00926978 · Status: TERMINATED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 21

Last updated 2018-11-01

No results posted yet for this study

Summary

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.

Conditions

Interventions

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.

Sponsors & Collaborators

  • Medstar Health Research Institute

    lead OTHER

Principal Investigators

  • Douglas Van Nostrand, MD · Director, Nuclear Medicine

Study Design

Allocation
NA
Purpose
OTHER
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2008-12-31
Primary Completion
2018-10-31
Completion
2018-10-31

Countries

  • United States

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00926978 on ClinicalTrials.gov