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

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.

Conditions

• Thyroid Cancer

Interventions

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

Sponsors & Collaborators

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

  lead NIH

Principal Investigators

• Joanna Klubo-Gwiezdzinska, M.D. · National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-07-29

Primary Completion

2035-11-01

Completion

2035-11-01

FDA Drug

Yes

Countries

• United States

Study Locations