To learn whether Flourine-18 Fluoro-deoxi-glucose positron emission tomography / computed tomography (F-18 FDG PET/CT) and dynamic contrast enhanced magnetic resonance imaging (DCE MRI) are better predictors of response to therapy than the current standard of care (CT or MRI).
This is a single arm prospective trial in patients with newly-diagnosed advanced renal cell cancer (RCC) who were scheduled for sunitinib therapy and utilized an extensive panel of quantitative metrics on baseline and interim FDG PET/CT to evaluate the predictive utility of each of these measurements. The objectives were to evaluate the FDG PET/CT measurement parameters for prediction of prognosis after sunitinib therapy in patients with RCC using histopathologic (post-therapy nephrectomy) or clinical follow-up for validation.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
17
nuclear medicine imaging technique which produces a three-dimensional image or picture of functional processes in the body
DCE MRI will be acquired using rapid intravenous bolus of gadolinium-DTPA (0.1 mmol/kg).
15 mCi iv
Stanford University School of Medicine
Stanford, California, United States
F-18 FDG Tumor Uptake (SUV Max)
The maximum standardized uptake value (SUVmax) is a measurement of tumor metabolism as determined by the PET scan before and after 12-weeks of sunitinib therapy. Decreased SUVmax correlates to a reduction of tumor metabolism. Increased SUVmax correlates to an increase in tumor metabolism. Reduction or increased SUVmax will be determined as the change from baseline in uptake of F18 FDG. Results were based on the European Organization for Research and Treatment of Cancer (EORTC) for predicting progression free survival. EORTC criteria is a ± 25% change of SUVmax for assessment of progressive disease, stable disease and partial response.
Time frame: 12 weeks minus baseline
Histopathology
Histopathologic findings were correlated to the pre-treatment 18F-fluorodeoxyglucose positron emission tomography (F-18 FDG PET/CT) scan. Outcome is reported as the number of participants for whom both histopathology and F-18 FDG PET/CT indicated that active cancers was present.
Time frame: 1 day
Initial Comprehensive Metabolic Panel
A comprehensive metabolic panel is a blood test that measures sugar (glucose) level, electrolyte and fluid balance, kidney function, and liver function. It was performed prior to the administration of gadolinium contrast. For patients with normal renal function, approximately 90% of gadolinium contrast is excreted through the urinary system. These patients have known renal cell carcinoma, so it was important to perform a metabolic function panel prior to gadolinium injection, specifically to determine kidney function. Reported as the number of patients for whom the initial comprehensive metabolic panel was within institutional standards.
Time frame: Prior to baseline DCE MRI
Adverse Events
Adverse events were monitored for on F-18 FDG PET/CT and DCE MRI imaging days: baseline (n=17); interim (n=12); and post-sunitinib therapy (n=17). Reported as the overall number of adverse events experienced.
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0.1 mmol/kg iv
50 mg/day po
Time frame: up to 12 months
Tumor Necrosis
The degree of tumor necrosis was measured using values obtained from dynamic contrast enhanced magnetic resonance imaging (DCE MRI) pre- and post-sunitinib therapy. Gadolinium contrast material given intravenously during the DCE MRI scan is used to improve visualization of blood vessels, tumors, and/or organs.
Time frame: 12 weeks
Tumor Size by Computed Tomography (CT) Scan
Tumor size was measured based on computed tomography (CT) pre- and post-sunitinib therapy. CT was performed immediately prior to the PET scan and is used to determine both the PET scan imaging area and PET image attenuation correction (AC). F-18 FDG PET provides the metabolic and physiologic data while CT provides the anatomical data.
Time frame: 12 weeks
Tumor Size by DCE Magnetic Resonance Imaging (MRI) Scan
Tumor size was measured using values obtained from DCE MRI pre- and post-sunitinib therapy. Gadolinium contrast material given intravenously during the DCE MRI scan is used to improve visualization of blood vessels, tumors, and/or organs.
Time frame: 12 weeks
DCE MRI AUC Peak Flow
Area under the curve (AUC) was measured using receiver operating characteristic (ROC) curve analysis. ROC curve analysis measures sensitivity (true-positives, correctly diagnosed positive pathologies) against specificity (true-negatives, correctly diagnosed negative pathologies or free of disease) of the DCE MRI scan. An area of 1.0 under the curve would equal a perfect test (with 100% sensitivity; 100% specificity) while an area of 0.5 would equal a useless test (50% sensitivity; 50% specificity).
Time frame: 12 weeks
Initial Tumor Size
Initial tumor size was measured using values obtained from computed tomography (CT) pre-sunitinib therapy. CT is performed immediately prior to the PET scan and is used to determine both the PET scan imaging area and PET image attenuation correction (AC). F-18 FDG PET provides the metabolic and physiologic data while CT provides the anatomical data.
Time frame: pre-sunitinib therapy