Comparison of PET/CT vs. PET/MRI Using 2 Radiopharmaceuticals

PRIMARY OBJECTIVES:

I. To evaluate if PET/CT and PET/MRI scanners provide equivalent results for evaluation of cancer patients.

OUTLINE:

Patients receive standard of care 18F-fludeoxyglucose (FDG) or Ga68-DOTA-TATE intravenously (IV). Within 45-60 minutes, patients then undergo PET/CT imaging immediately followed by PET/MRI. Each participant is to receive 18-FDG or 68Ga-DOTA-TATE only, no participant was to receive both radiotracers.

• F-18 FDG (Drug): Radiolabel for positron emission tomography / computed tomography (PET/CT) and computed tomography (PET/CT) imaging
• Ga-68-DOTA-TATE (Drug): Radiolabel for positron emission tomography / computed tomography (PET/CT) and computed tomography (PET/CT) imaging
• Positron Emission Tomography / Computed Tomography (PET/CT) Scan (Device): Scan using a regular medical care (IDE-exempt) Discovery 600 / 690 PET/CT scanner.
• Positron Emission Tomography / Magnetic Resonance Imaging (PET/MRI) Scan (Device): Scan using a NOVEL GE PET/MRI scanner.

Primary outcomes

• Absolute Accuracy of SUV Max of PET/CT vs PET/MRI [4 hours]: Standardized uptake value max (SUVmax) is a measurement of the maximum radiopharmaceutical uptake value within the region of interest (ROI). SUVmax is calculated as the ratio of activity concentration:injected dose/body weight. The outcome is reported as the mean SUVmax with standard deviation (SD), reported for 8 specific organs or bodily locations.

Secondary outcomes

• PET/CT vs PET/MRI Difference in Standardized Uptake Value Max (SUVmax), by Radiotracer [estimated average of 2 hours]: Standardized uptake value max (SUVmax) is a measurement of the maximum radiopharmaceutical uptake within the region of interest (ROI). Relative accuracy of a particular radiotracer in a particular tissue is determined by expressing the absolute accuracy (obtained in the primary outcome measure) in terms of percent difference between SUVmax values obtained from PET/CT and PET/MR. Percentage difference is expressed as the difference of the means in SUVmax for the PET/CT and PET/MRI scan procedures for the particular radiotracer, divided by the mean between the values for the 2 scan procedures. The closer the percent difference is to 0%, the better the agreement between the two scanners. The outcome is expressed as the percentage difference, a number without dispersion.

Sex: All, ages: 18 Years to any

INCLUSION CRITERIA

* Cancer diagnosis
* Capable of complying with study procedures
* Able to remain still for duration of imaging procedure (approximately 90 minutes total)
* Written informed consent

EXCLUSION CRITERIA

* Pregnant or nursing
* Metallic implants
* Impaired renal function

Participant flow

Outcome results

• Absolute Accuracy of SUV Max of PET/CT vs PET/MRI (Primary), Mean, ratio: 18F-FDG PET/CT Scan 1.78 +/- 0.42; 18F-FDG PET/MRI Scan 1.08 +/- 0.38; 68Ga-DOTA-TATE PET/CT Scan 0.54 +/- 0.22; 68Ga-DOTA-TATE PET/MRI Scan 0.51 +/- 0.19
• PET/CT vs PET/MRI Difference in Standardized Uptake Value Max (SUVmax), by Radiotracer (Secondary), Number, Percentage difference: 18-FDG PET/CT and PET/MRI 48.95; 68Ga DOTA-TATE PET/CT and PET/MRI 5.71

Adverse events

Time frame: 1 day

• Study Protocol and Statistical Analysis Plan (PDF, 2016-04-22)

• Andrei Iagaru, Principal investigator, Stanford University