11C Methionine PET for the Detection of Hyperfunctional Parathyroid Tissues

Study Overview
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Brief Summary
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The overall sensitivity and specificity of 11C-MET PET/CT is superior to 18F-FDG PET/CT and conventional SPECT-CT for the detection of abnormal parathyroid glands.

Detailed Description
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STUDY OBJECTIVES Primary: To compare the accuracy, sensitivity and specificity of 11C-methionine (MET) PET/CT and 99mTc-MIBI SPECT-CT in the detection of pathologic parathyroid glands in patients with primary hyperparathyroidism. Secondary:To compare the accuracy, sensitivity and specificity of 11C-MET and 18F-FDG PET/CT scans in the detection of pathologic parathyroid glands in patients with primary hyperparathyroidism. STUDY DESIGN A phase II diagnostic imaging, single-centre study to compare the accuracy of 11C-MET PET/CT with standard 99mTc-MIBI SPECT-CT and with 18F-FDG PET/CT imaging in patients with primary hyperparathyroidism. STUDY POPULATION Number of Subjects: 50 patients Number of groups: 1: 50 with primary hyperparathyroidism. Age/Gender: Age greater than or equal to 19 years / Male and Female Study specific requirements: Subjects with clinically suspected primary hyperparathyroidism who require 99mTc-MIBI SPECT-CT parathyroid imaging. INVESTIGATIONAL PRODUCT Product: 11C-Methionine Route of administration: Intravenous Dosage(s) and frequency: Radioactive dose of 11C-Methionine of 6 MBq per kilogram body weight per injection (maximum dose of 555 MBq); one injection per patient. COMPARATOR PRODUCTS Product: 99mTc-Methoxyisobutylisonitrite; 18F-Fluorodeoxyglucose Route of administration: Intravenous Dosage(s) and frequency: (1) Radioactive dose of 99mTc-Methoxyisobutylisonitrite of 555 - 740 MBq per injection; one injection per patient. (2) Radioactive dose of 18F-Fluorodeoxyglucose of 296 - 521 MBq per injection; one injection per patient. EVALUATION CRITERIA Efficacy: The comparison of the accuracy, sensitivity, and specificity of 11C-MET PET/CT with 99mTc-MIBI SPECT-CT and 18F-FDG PET/CT in the detection of pathologic parathyroid glands in patients with primary hyperparathyroidism. Safety: Vital signs before and following 11C-MET administration; adverse events collection.

Official Title
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Pre-operative Parathyroid Imaging: a Comparison of 11C-Methionine PET, 18F-FDG PET AND SPEC-CT for the Detection of Hyperfunctional Parathyroid Tissues

Conditions
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Primary Hyperparathyroidism

Intervention / Treatment
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* Radiation: 11C-Methionine PET/CT scanning
* Radiation: 18F-FDG PET/CT scanning
* Radiation: SPECT-CT scanning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults > age 18; Able to provide written informed consent; Subjects with biochemical evidence, including elevated serum calcium and PTH levels, of primary hyperparathyroidism. Exclusion Criteria: Subjects with previous successful parathyroidectomy and parathyroid tissue reimplantation; Pregnancy; Subjects who are unable to tolerate the physical/logistical requirements of completing two PET/CT scans, including lying still for a prolonged period of time and receiving two intravenous injections. Subjects who exceed the safe weight limit of the PET/CT bed (204.5 kg) or who cannot fit through the PET/CT machine (diameter 70cm).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Primary hyperparathyroidism<br>Subjects with biochemical evidence, including elevated serum calcium and PTH levels, of primary hyperparathyroidism. All patients will undergo 11C-methionine PET/CT, SPECT-CT and 18F-FDG PET/CT scanning. | Radiation: 11C-Methionine PET/CT scanning<br>* PET with the radiopharmaceutical carbon-11 methionine (11C-MET) has been considered to improve diagnosis due to a superior spatial resolution and higher specificity compared to other radiotracers such as 18F-FDG. For the 11C-MET PET/CT, the patient will receive an intravenous bolus injection of 11C-MET as manufactured at the BCCA production facility at a dose of 6 (0.16 mCi) MBq per kilogram but not to exceed 555 MBq (15 mCi).<br>* Other names: 11C-MET;Radiation: 18F-FDG PET/CT scanning<br>* For PET/CT scans, the patient will first receive an intravenous bolus injection of 18F-FDG as manufactured at the BCCA production facility in a dose determined by body weight but not to exceed 521 MBq (14.1 mCi). Our standard adult prescription (70kg adult) for 18F-FDG is 296 MBq (8.0 mCi). The target dose for body scans is increased by 59.2 MBq (1.6 mCi) for every 20 kg increase in body weight to a maximum target dose of 474 MBq (12.8 mCi).<br>Radiation: SPECT-CT scanning<br>* For the SPECT-CT scan, each injection of intravenous 99mTc-MIBI is dosed at a maximum of 20 mCi (740MBq), as per usual standard of care. The energy window of each scan is at 140 keV, consistent with the standard of SPEC-CT imaging techniques.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the sensitivity of 11C-MET PET/CT, SPECT-CT and 18F-FDG PET/CT in the detection of pathologic parathyroid glands in patients with primary hyperparathyroidism | Sensitivity is the percentage of patients that were correctly identified to have an abnormal parathyroid gland by the imaging studies. | Patient will undergo the scans at baseline | 
| To compare the specificity of11C-MET PET/CT, SPECT-CT and 18F-FDG PET/CT in the detection of pathologic parathyroid glands in patients with primary hyperparathyroidism | Specificity is defined as the percentage of patients that were correctly rejected for having an abnormal parathyroid gland by the imaging studies. | Patient will undergo the scans at baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate the safety profile of 11C-MET PET/CT. | All adverse events will be recorded. An Adverse Event (AE) is any untoward, undesired, unplanned medical occurrence in a participant and does not necessarily have a causal relationship with the study intervention. Expected adverse events from PET/CT scans include bruising, bleeding or infection at the site of intravenous radiotracer injection. Other expected adverse events include feeling of discomfort or claustrophobia from being in the scanner. | Up to 2 weeks |