Thyroid CancerPhase 2NCT06961084
Comparison of I-124 PET/CT for the Diagnosis of Thyroid Cancer
A Phase 2 study testing Iodine-124 and Positron Emission Tomography (PET)/Computerized tomography (CT) in people with Thyroid Cancer, run by Thomas Hope at 1 site in United States.
Trial summary
Persons diagnosed with thyroid cancer are often treated initially with a thyroidectomy, which is followed by ablation using Iodine-131, a therapy which has been shown to be effective and safe. Read more about this study
- Who is it for?
- Ages 13 years and older
- Conditions the study is for
- Thyroid Cancer
- What is being tested?
- Iodine-124 and Positron Emission Tomography (PET)/Computerized tomography (CT)
- Type of treatment
- Pill or oral medicine, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 62 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Dec 2025to 1 Apr 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 13 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Age >= 13 years.
- Histopathologically confirmed differentiated or poorly differentiated thyroid cancer.
- Meeting criteria for one of the following two populations:
- American Thyroid Association (ATA) intermediate or high-risk thyroid cancer and planning on treatment using I-131.
- Metastatic disease on imaging (CT, MRI, ultrasound or FDG PET), and considering localized therapy such as surgery and radiation therapy.
- Undergone total thyroidectomy.
- Planned I-123 imaging within 45 days after enrollment.
- Ability to understand a written informed consent document, and the willingness to sign it.
Who cannot join
- Unlikely to comply with study procedures, restrictions and requirements and judged by the Investigator to be unsuitable for participation.
- Known pregnancy.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California, San Francisco
San Francisco, California, 94122
Maya Aslam, Maya.Aslam@ucsf.edu
877-827-3222, cancertrials@ucsf.edu
About this study
Official title: Comparison of I-124 PET/CT to I-123 Whole Body Imaging for the Diagnosis of Thyroid
Persons diagnosed with thyroid cancer are often treated initially with a thyroidectomy, which is followed by ablation using Iodine-131, a therapy which has been shown to be effective and safe. Imaging of metastatic thyroid cancer has been performed with whole body I-131 and Iodine 123 (I-123) imaging for many decades and use I-123 for staging studies. Iodine 124 (I-124) is a radioisotope of iodine which emits a positron and is imaged using PET (positron emission tomography). This is a single arm prospective trial that evaluates the ability of Iodine-124 (I-124) to detect metastatic thyroid cancer compared to non-interventional, usual care I-123 and I-131 images.
Read the detailed description
PRIMARY OBJECTIVES:
- Agreement between 1-124 PET and 1-123/1-131 SPECT.
SECONDARY OBJECTIVES:
- Sensitivity and specificity of I-124 PET to detect metastatic thyroid cancer compared to composite standard.
- Reclassification rate of I-124 PET compared to I-123 SPECT.
- Inter-reader variability for I-124 PET and I-123 SPECT.
- Safety of I-124 PET.
- Participant level detection rate for I-124 in the overall population.
- Participant level detection rate for I-124 in participants who have negative I-123 SPECT.
- Comparison of lesion detection between I-124 PET and 24 hour I-123 SPECT.
- Comparison of lesion detection between I-124 PET and post-treatment I-131 SPECT.
EXPLORATORY OBJECTIVES:
- Ability to predict lesion absorbed dose using I-124 PET/CT.
OUTLINE:
All participants will have a single PET/CT scan after administration of I-124 and will be followed for up to 3-5 days by phone for evaluation of adverse events. A subset of participants being evaluated for dosimetry will be imaged up to two additional times over five days after administration. Data from other scans for comparison will be obtained from the participant's medical record.
- Conditions
- Thyroid Cancer
- Being tested
- Iodine-124, Positron Emission Tomography (PET)/Computerized tomography (CT)
- Keywords
- Imaging Studies
- Medical subject headings
- Thyroid Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Iodine-124Drug
Also called I-124, I-124 Radioisotope
Given Orally
Positron Emission Tomography (PET)/Computerized tomography (CT)Procedure or surgery
Also called PET/CT
Combination of PET and CT imaging
| Study group | Role | What they receive |
|---|---|---|
| Intervention: I-124 PET/CT | Experimental | All participants will be administered an oral dose of 60 to 85 megabecquerel (MBq) +/- 10% for I-124 (capsule) prior to the Positron Emission Tomography (PET) imaging. Scan coverage will extend from the vertex to the mid-thighs and in certain circumstances, coverage may be extended to the toes. Imaging will be acquired 20-28 hours after I-124 administered. Participants will be followed up for any adverse events for up to 5 days after the scan has been completed. Receives: Drug: Iodine-124; Procedure: Positron Emission Tomography (PET)/Computerized tomography (CT) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of agreement between I-124 PET and I-123/I-131 SPECT (participant)
Participant-level agreement between I-124 PET and the combination of I-123/I-131 SPECT will be measured. A participant will be classified as showing agreement only if all six regions demonstrate agreement; disagreement in one or more regions will result in a classification of disagreement. Positive percent agreement (PPA) and negative percent agreement (NPA) will be reported with corresponding 95% confidence intervals.
Measured: 1 day
Number of agreement between 1-124 PET and 1-123/1-131 SPECT (region)
Region-level agreement between 1-124 PET and the combination of 1-123/1-131 SPECT will be determined by Individual reader and through a consensus read. A region is in agreement if I-124 PET and I-123/I-131 SPECT results align, either as true positive (both positive) or true negative (both negative). Disagreement occurs when the results diverge, categorized as false positive (I-124 PET positive, but I-123/I-131 SPECT negative) or false negative (I-124 PET negative, but I-123/I-131 SPECT positive).
Measured: 1 day
Secondary outcomes (14)
Overall specificity of I-124 PET for detection of metastatic thyroid cancer (participant)
Specificity of I-124 is defined as the proportion of lesions that will be characterized as negative on I-124 PET when compared to the composite truth standard across participants. The composite truth standard is determined by a panel of highly qualified physicians and researchers and will be used to determine true positive (TP), false positive (FP), true negative (TN) and false negative (FN) by participant: o TP: I-124 PET read as positive for tumor, and composite truth standard determined to have tumor. o FP: I-124 PET read as positive for tumor, and composite truth standard determined to not contain tumor. o TN: I-124 PET read as negative for tumor, and composite truth standard determined to not contain tumor. o FN: I-124 PET read as negative for tumor, and composite truth standard determined to contain tumor. Specificity ranges from 0 to 100%, with higher values indicating a better ability for the scan to detect healthy individuals
Measured: 1 day
Overall specificity of I-124 PET for detection of metastatic thyroid cancer (region)
Specificity of I-124 is defined as the proportion of lesions that will be characterized as negative on I-124 PET when compared to the composite truth standard by region. The composite truth standard is determined by a panel of highly qualified physicians and researchers and will be used to determine true positive (TP), false positive (FP), true negative (TN) and false negative (FN) by region: o TP: I-124 PET read as positive for tumor, and composite truth standard determined to have tumor. o FP: I-124 PET read as positive for tumor, and composite truth standard determined to not contain tumor. o TN: I-124 PET read as negative for tumor, and composite truth standard determined to not contain tumor. o FN: I-124 PET read as negative for tumor, and composite truth standard determined to contain tumor. Specificity ranges from 0 to 100%, with higher values indicating a better ability for the scan to detect healthy individuals
Measured: 1 day
Overall sensitivity of I-124 PET for detection of metastatic thyroid cancer (participant)
Sensitivity of I-124 is defined as the proportion of lesions that will be characterized as positive on I-124 PET when compared to the composite truth standard on a participant level. The composite truth standard is determined by a panel of highly qualified physicians and researchers and will be used to determine true positive (TP), false positive (FP), true negative (TN) and false negative (FN) across participants: o TP: I-124 PET read as positive for tumor, and composite truth standard determined to have tumor. o FP: I-124 PET read as positive for tumor, and composite truth standard determined to not contain tumor. o TN: I-124 PET read as negative for tumor, and composite truth standard determined to not contain tumor. o FN: I-124 PET read as negative for tumor, and composite truth standard determined to contain tumor. Sensitivity ranges from 0 to 100%, with higher values indicating a more sensitive scan.
Measured: 1 day
Overall sensitivity of I-124 PET for detection of metastatic thyroid cancer (region)
Sensitivity of I-124 is defined as the proportion of lesions that will be characterized as positive on I-124 PET when compared to the composite truth standard by region. The composite truth standard is determined by a panel of highly qualified physicians and researchers and will be used to determine true positive (TP), false positive (FP), true negative (TN) and false negative (FN) by region: o TP: I-124 PET read as positive for tumor, and composite truth standard determined to have tumor. o FP: I-124 PET read as positive for tumor, and composite truth standard determined to not contain tumor. o TN: I-124 PET read as negative for tumor, and composite truth standard determined to not contain tumor. o FN: I-124 PET read as negative for tumor, and composite truth standard determined to contain tumor. Sensitivity ranges from 0 to 100%, with higher values indicating a more sensitive scan.
Measured: 1 day
Reclassification Rate
Reclassification rate is defined as the proportion of participants what will be characterized as metastatic on I-124 Positron Emission Tomography (PET) that are characterized as localized or nodal only disease on a non-investigational, usual care I-123 Single-photon emission computed tomography (SPECT).
Measured: 1 day
Proportion of participants with treatment-related adverse events
Proportion of participants with treatment-related adverse events, as classified and graded by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE version 5.0). Results will be reported separately for adults and pediatric participants.
Measured: Up to 5 days
Proportion of participants with positive I-124 PET in the overall population
The participant level detection rate will be assessed by calculating the number of participants interpreted as having a positive I-124 PET divided by the total number of participants with a scan evaluated by a reader.
Measured: 1 day
Proportion of participants with positive I-124 PET in participants who have negative I-123 SPECT
In the subset of participants where the consensus read of the I-123 imaging study was negative, then the participant level detection rate for this population will be determined. The detection rate will be assessed by calculating the number of participants interpreted as having a positive I-124 PET divided by the total number of participants with a negative I-123 SPECT scan evaluated by a reader.
Measured: 1 day
Mean of total number of lesions characterized as positive on I-124 PET and 24 hour I-123 SPECT
The mean total number of lesions detected for each participant using I-124 and I-123 taken within 24 hours (with a maximum of 10 lesions per region) will be reported along with the variance.
Measured: 1 day
Mean of total number of lesions characterized as positive on both I-124 PET and 7-day post I-131
The mean total number of lesions detected for each participant using I-124 and I-131 taken within 7 days (with a maximum of 10 lesions per region) will be reported along with the variance.
Measured: 1 day
Inter-reader reliability (IRR) for I-124 PET (region)
Three blinded readers will interpret the non-investigational, usual care I-123 imaging and the I-124 imaging by region. A Cohen's Kappa will be used to measure the inter-reader variability for I-124 and I-123 separately. Kappa statistics range from -1 to 1 with higher values correspond to higher inter-rater reliability.
Measured: 1 day
Inter-reader reliability (IRR) for I-124 PET (participant)
Three blinded readers will interpret the non-investigational, usual care I-123 imaging and the I-124 imaging per participants. A Cohen's Kappa will be used to measure the inter-reader variability for I-124 and I-123 separately. Kappa statistics range from -1 to 1 with higher values correspond to higher inter-rater reliability.
Measured: 1 day
Intra-reader reliability (Intra-RR) for I-124 PET (participant)
Three blinded readers will interpret fifteen I-124 imaging studies a second time with a minimum 6 week washout period. A Cohen's Kappa will be used to measure the intra-reader variability for I-124. Kappa statistics range from -1 to 1 with higher values corresponding to higher intra-rater reliability.
Measured: 1 day
Biodistribution of I-124 measured by standardized uptake value (SUV) in tumor and target organs
SUV will be measured in tumor and target organs by PET imaging to characterize the biodistribution of I-124. SUV measurements will be descriptively reported for adults and pediatrics separately to compare biodistribution between these age groups.
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2025
- Study start4 Dec 2025
- Primary completion1 Apr 2028 (estimated)
- Study completion1 Apr 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Thyroid CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 62 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Thomas Hope
- Sponsor type
- University, hospital or other
- Collaborators
- United States Department of Defense
- Responsible party
- Sponsor-investigator, Thomas Hope, University of California, San Francisco
- Investigators
- Thomas Hope, MD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06961084
- Sponsor's protocol ID
- 249212
- Other IDs
- NCI-2025-03041
- Status last verified
- Jun 2026
- First submitted
- 29 Apr 2025
- Last updated
- 18 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of I-124 PET/CT to I-123 Whole Body Imaging for the Diagnosis of Thyroid
- ClinicalTrials.gov ID
- NCT06961084
- Acronym / sponsor ID
- 249212
- Conditions
- Thyroid Cancer
- Keywords
- Imaging Studies
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 62 participants (estimated)
- Lead sponsor
- Thomas HopeUniversity, hospital or other
- Collaborators
- United States Department of Defense
- Study start
- 4 Dec 2025 (actual)
- Primary completion
- 1 Apr 2028 (estimated)
- Study completion
- 1 Apr 2028 (estimated)
- First posted
- 7 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Persons diagnosed with thyroid cancer are often treated initially with a thyroidectomy, which is followed by ablation using Iodine-131, a therapy which has been shown to be effective and safe. Imaging of metastatic thyroid cancer has been performed with whole body I-131 and Iodine 123 (I-123) imaging for many decades and use I-123 for staging studies. Iodine 124 (I-124) is a radioisotope of iodine which emits a positron and is imaged using PET (positron emission tomography). This is a single arm prospective trial that evaluates the ability of Iodine-124 (I-124) to detect metastatic thyroid cancer compared to non-interventional, usual care I-123 and I-131 images.
Detailed description
PRIMARY OBJECTIVES:
- Agreement between 1-124 PET and 1-123/1-131 SPECT.
SECONDARY OBJECTIVES:
- Sensitivity and specificity of I-124 PET to detect metastatic thyroid cancer compared to composite standard.
- Reclassification rate of I-124 PET compared to I-123 SPECT.
- Inter-reader variability for I-124 PET and I-123 SPECT.
- Safety of I-124 PET.
- Participant level detection rate for I-124 in the overall population.
- Participant level detection rate for I-124 in participants who have negative I-123 SPECT.
- Comparison of lesion detection between I-124 PET and 24 hour I-123 SPECT.
- Comparison of lesion detection between I-124 PET and post-treatment I-131 SPECT.
EXPLORATORY OBJECTIVES:
- Ability to predict lesion absorbed dose using I-124 PET/CT.
OUTLINE:
All participants will have a single PET/CT scan after administration of I-124 and will be followed for up to 3-5 days by phone for evaluation of adverse events. A subset of participants being evaluated for dosimetry will be imaged up to two additional times over five days after administration. Data from other scans for comparison will be obtained from the participant's medical record.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Intervention: I-124 PET/CT | Experimental | Drug: Iodine-124, Procedure: Positron Emission Tomography (PET)/Computerized tomography (CT)All participants will be administered an oral dose of 60 to 85 megabecquerel (MBq) +/- 10% for I-124 (capsule) prior to the Positron Emission Tomography (PET) imaging. Scan coverage will extend from the vertex to the mid-thighs and in certain circumstances, coverage may be extended to the toes. Imaging will be acquired 20-28 hours after I-124 administered. Participants will be followed up for any adverse events for up to 5 days after the scan has been completed. |
Who may qualify
- Ages
- 13 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (8 listed)
- Age >= 13 years.
- Histopathologically confirmed differentiated or poorly differentiated thyroid cancer.
- Meeting criteria for one of the following two populations:
- Undergone total thyroidectomy.
- Planned I-123 imaging within 45 days after enrollment.
Key exclusion criteria (2 listed)
- Unlikely to comply with study procedures, restrictions and requirements and judged by the Investigator to be unsuitable for participation.
- Known pregnancy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Iodine-124Also: I-124, I-124 RadioisotopeGiven Orally | Drug | Intervention: I-124 PET/CT |
| Positron Emission Tomography (PET)/Computerized tomography (CT)Also: PET/CTCombination of PET and CT imaging | Procedure or surgery | Intervention: I-124 PET/CT |
Primary outcome
Proportion of agreement between I-124 PET and I-123/I-131 SPECT (participant)
Time frame: 1 day
Participant-level agreement between I-124 PET and the combination of I-123/I-131 SPECT will be measured. A participant will be classified as showing agreement only if all six regions demonstrate agreement; disagreement in one or more regions will result in a classification of disagreement. Positive percent agreement (PPA) and negative percent agreement (NPA) will be reported with corresponding 95% confidence intervals.
Number of agreement between 1-124 PET and 1-123/1-131 SPECT (region)
Time frame: 1 day
Region-level agreement between 1-124 PET and the combination of 1-123/1-131 SPECT will be determined by Individual reader and through a consensus read. A region is in agreement if I-124 PET and I-123/I-131 SPECT results align, either as true positive (both positive) or true negative (both negative). Disagreement occurs when the results diverge, categorized as false positive (I-124 PET positive, but I-123/I-131 SPECT negative) or false negative (I-124 PET negative, but I-123/I-131 SPECT positive).
14 secondary outcomes
Overall specificity of I-124 PET for detection of metastatic thyroid cancer (participant)
Time frame: 1 day
Overall specificity of I-124 PET for detection of metastatic thyroid cancer (region)
Time frame: 1 day
Overall sensitivity of I-124 PET for detection of metastatic thyroid cancer (participant)
Time frame: 1 day
Overall sensitivity of I-124 PET for detection of metastatic thyroid cancer (region)
Time frame: 1 day
Reclassification Rate
Time frame: 1 day
Proportion of participants with treatment-related adverse events
Time frame: Up to 5 days
Proportion of participants with positive I-124 PET in the overall population
Time frame: 1 day
Proportion of participants with positive I-124 PET in participants who have negative I-123 SPECT
Time frame: 1 day
Mean of total number of lesions characterized as positive on I-124 PET and 24 hour I-123 SPECT
Time frame: 1 day
Mean of total number of lesions characterized as positive on both I-124 PET and 7-day post I-131
Time frame: 1 day
Inter-reader reliability (IRR) for I-124 PET (region)
Time frame: 1 day
Inter-reader reliability (IRR) for I-124 PET (participant)
Time frame: 1 day
Intra-reader reliability (Intra-RR) for I-124 PET (participant)
Time frame: 1 day
Biodistribution of I-124 measured by standardized uptake value (SUV) in tumor and target organs
Time frame: 1 day
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jun 2026.
- Individual participant dataSharing planned: No
Related trials for Thyroid Cancer
Recruiting
NIRAF-Guided Parathyroid Identification During Thyroidectomy
Hypocalcemia, Hypoparathyroidism
Active, not recruitingPhase 1
Prospective Exploratory Study of FAPi PET/CT With Histopathology Validation in Patients With Various Cancers
Bladder Carcinoma, Cervical Carcinoma
Not yet recruitingPhase 1/2
177Lu-DOTA-EB-TATE in Adult Patients With Metastatic, Radioactive Iodine Non-Responsive Oncocytic (Hurthle-Cell) Thyroid Cancer
Thyroid Cancer
RecruitingObservational study
DICER1-related Pleuropulmonary Blastoma Cancer Predisposition Syndrome: A Natural History Study
Pleuropulmonary Blastoma, Cystic Nephroma
Recruiting
Evaluation of DNA Methylation Signatures for the Diagnosis and Management of Thyroid Nodules
Thyroid Gland Carcinoma
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Thomas Hope, MD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Iodine-124 and Positron Emission Tomography (PET)/Computerized tomography (CT) in people with Thyroid Cancer, run by Thomas Hope at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Maya Aslam ((415) 514-8987, Maya.Aslam@ucsf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of agreement between I-124 PET and I-123/I-131 SPECT (participant) (time frame: 1 day). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jun 2026.