NCT03841617

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

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · NIH
• Sex: All
• Age: 18 Years – 90 Years
• Healthy volunteers: Not accepted

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.

Conditions

• Thyroid Cancer

Interventions

Type	Name	Description
DRUG	Thyrogen	intramuscular injection administered once/day for 2 consecutive days at Week 3; then once annually for subjects who meet criteria.
RADIATION	I-131	therapeutic dose administered orally to treat thyroid cancer at Week 8. 5-7 days later, the post-treatment I-131 Whole Body scan w/ SPECT is performed; then administered once annually, if the patient needs to be re-treated
RADIATION	I-124	one capsule ingested orally once at Week 3, and Week 8; then administered once annually to subjects who meet criteria.
OTHER	Thyroid hormone withdrawal	withdrawal of thyroid hormone during weeks 4 through 8

Timeline

• Start date: 2019-07-29
• Primary completion: 2035-11-01
• Completion: 2035-11-01
• First posted: 2019-02-15
• Last updated: 2026-04-14

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study