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The Use of 124-I-PET/CT Whole Body and Lesional Dosimetry in Differentiated Thyroid Cancer

Phase 2
Recruiting
Conditions
Thyroid Cancer
Interventions
Radiation: I-131
Radiation: I-124
Other: Thyroid hormone withdrawal
Registration Number
NCT03841617
Lead Sponsor
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Brief Summary

Study rationale

High risk patients with differentiated thyroid cancer (DTC) require therapy with 131 I under thyroid stimulating hormone (TSH) stimulation. There are two methods of TSH stimulation endogenous by thyroid hormone withdrawal (THW) leading to hypothyroidism and exogenous by injection of human recombinant TSH (rhTSH Thyrogen). The appropriate 131-I activity utilized for treatment is either based on empiric fixed dosage choice or individually determined activity based on 131 I dosimetric calculations. Although dosimetry utilizing radioactive iodine isotope 131 I enables calculation of maximum safe dose, it does not estimate the tumoricidal activity necessary to destroy the metastatic lesions. The alternative radioactive isotope of iodine -124 I, used for positron emission tomography (PET) imaging, might be used for calculation not only the maximum safe131 I dose, but also to predict the absorbed dose in the metastatic lesions.

Study objectives

The primary objective of this study is to compare the 124 I -PET/CT lesional and whole body dosimetry in each individual patient with metastatic radioiodine (RAI)-avid thyroid cancer under preparation with rhTSH and THW. The secondary objective is to evaluate the predicted by PET/CT lesional uptake with the early response to therapy.

Study design

This is a phase 2 pilot prospective cohort study comparing the lesional and whole body dosimetry within each patient undergoing exogenous (rhTSH) and endogenous (THW) TSH stimulation and followed for 5 years.

Interventions

Each study participant will undergo rhTSH and THW-aided 124 I-PET/CT dosimetric evaluations and will be subsequently treated with THW-aided RAI activity based on dosimetric calculations enabling maximum safe dosage. The patients will be followed in 12+/-3 months intervals for 5 years.

Sample size and population

This pilot study will include 30 patients with high risk differentiated thyroid cancer presenting with distant and/or loco-regional metastases.

Detailed Description

Study Description:

Each study participant will undergo rhTSH and THW-aided 124IPET/ CT dosimetric evaluations and will be subsequently treated with THW-aided RAI activity based on dosimetric calculations enabling maximum safe dosage.

Objectives:

Primary objective: To compare the 124I -PET/CT lesional and whole body dosimetry in each individual patient with metastatic radioiodine (RAI)-avid thyroid cancer under preparation with rhTSH and THW.

Secondary objective: To evaluate the predicted by PET/CT lesional uptake with the early response to therapy.

Endpoints:

Primary Endpoint: The predicted radiation dose measured as rads per lesion compared per each measurable lesion between the dose calculated under rhTSH and under THW.

Secondary Endpoints: Area under the curve analyzing the association of dose per lesion measured in rads and objective response to treatment at 1, 2, 3, 4, 5 years landmarks.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
30
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
124I PET/CT scan after rhTSHThyrogen124I PET/CT scan after preparation with human recombinant TSH
124I PET/CT scan after rhTSHI-131124I PET/CT scan after preparation with human recombinant TSH
124I PET/CT scan after rhTSHI-124124I PET/CT scan after preparation with human recombinant TSH
124I PET/CT scan after thyroid hormone withdrawalI-131124I PET/CT scan after preparation with thyroid hormone withdrawal
124I PET/CT scan after thyroid hormone withdrawalThyroid hormone withdrawal124I PET/CT scan after preparation with thyroid hormone withdrawal
124I PET/CT scan after thyroid hormone withdrawalI-124124I PET/CT scan after preparation with thyroid hormone withdrawal
Primary Outcome Measures
NameTimeMethod
Comparison of the whole body and lesional 124I uptake within each patient prepared for imaging with human recombinant TSH (rhTSH) and thyroid hormone withdrawal (THW)9 weeks

Whole body and lesional uptake of 124I calculated after preparation with human recombinant TSH (rhTSH) compared to dosimetry calculated after preparation using thyroid hormone withdrawal (THW)

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

National Institutes of Health Clinical Center

🇺🇸

Bethesda, Maryland, United States

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