A Phase 2 interventional study of Iodine-124 and Positron Emission Tomography (PET)/Computerized tomography (CT) in Thyroid Cancer, sponsored by Thomas Hope. Recruiting at 1 site in United States. Open to participants aged 13 Years and older. Per ClinicalTrials.gov, last updated 2026-06-18.
Sponsored by Thomas Hope · Phase 2, Interventional, and Diagnostic
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.
PRIMARY OBJECTIVES:
1) Agreement between 1-124 PET and 1-123/1-131 SPECT.
SECONDARY OBJECTIVES:
EXPLORATORY OBJECTIVES:
1. 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.
785 studies on the registry are indexed under Thyroid Neoplasms; 204 are open to participants now.
This study's planned enrollment of 62 is above the median of 53 across 520 interventional studies indexed under Thyroid Neoplasms.
Browse Thyroid Neoplasms studies →Thomas Hope is the lead sponsor of 15 studies on the registry; 5 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 5 (56%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Meeting criteria for one of the following two populations:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Drug: Iodine-124 · Procedure: Positron Emission Tomography (PET)/Computerized tomography (CT)
Given Orally
Also known as: I-124, I-124 Radioisotope
Combination of PET and CT imaging
Also known as: PET/CT
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.
Time frame: 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).
Time frame: 1 day
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
Time frame: 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
Time frame: 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.
Time frame: 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.
Time frame: 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).
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 1 day
Plan to share: No
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Started Dec 2025 (actual). Primary completion is estimated for Apr 2028, 27 months after the start.
Of 77 non-industry phase 2 interventional studies under Thyroid Neoplasms, half reached primary completion within 84 months of starting (the median), counting those still running; a quarter within 50 and three quarters within 124. This study's planned 27 months is below that.
Counting every sponsor, half of 92 studies reached it within 73 months; a quarter within 39 and three quarters within 119.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Iodine-124
Thomas Hope