Evaluation of the Use of the FUR to Quantify Tumor Glucose Consumption in Oncologic PET

This study tests a new way to measure how much sugar (glucose) a tumor is consuming using a PET scan. This could help doctors better assess cancer activity and treatment response without needing repeated blood draws. **You may be eligible if...** - You are 18 or older - You are already scheduled to have an FDG PET/CT scan as part of your standard cancer care - You have fasted for at least 4 hours before the scan - You have not exercised in the past 24 hours **You may NOT be eligible if...** - You have diabetes (fasting blood sugar above 7 mmol/L) - You have not fasted before the scan - You have recently had chemo or radiation therapy for cancer - You have an active inflammation or infection (fever, high CRP) - You cannot lie still for the duration of the scan - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.