TABLE 2

Patient Preparation Recommendations

CategorySNMMI (2)EANM (3)ACR (5)NCI (4)Proposed standard protocol
Fasting periodAt least 4–6 hAt least 6 hMinimum of 4 hMinimum of 4 hMinimum of 6 h
HydrationOral hydration with water1 L of water by mouth 2 h before injection; 0.5 L of water during uptake period as toleratedTypically oral hydration, intravenous in special circumstancesAt least 2–3 (12 oz [355 mL] each) glasses of water during fasting and 250–500 mL of water after injection and before scanning1–2 L of plain water as tolerated during the 4 h immediately before PET/CT scan
DietNot statedNot statedNot statedLow-carbohydrate diet for 24 hHigh-protein, low-carbohydrate diet for 24 h
Physical activity/exercise restrictionNot statedAt least 6 h before PET study1 d before scan1 d before scanAvoid for minimum of 24 h (ideally 48 h) before scan
MedicationsNot statedTake as prescribedNot statedNot statedTake as directed
Glucose level before tracer injection150–200 mg/dL<120 mg/dL (<7 mmol/L)Not statedNondiabetic patients,<120 mg/dL; diabetic patients, 150–200 mg/dL<200 mg/dL
PremedicationLorazepam or diazepam before 18F-FDG injection to reduce uptake by BAT and skeletal muscle or β-blockers to reduce BAT uptakeSedatives such as short-acting benzodiazepines in patients with head and neck tumors, anxiety, or claustrophobiaPremedication for anxiety, if indicated, without mention of a specific recommendationA sedative such as diazepam in extremely anxious patients or when area of interest is head and neckOral alprazolam, 0.5 mg, for patients with head and neck cancer, claustrophobia, or anxiety; oral β-blocker (propranolol, 20 mg) 1 h before 18F-FDG injection for patients with prominent BAT
Timing of PETNot stated10 d after last chemotherapy dose; 3 mo after radiationNot statedAt least 2 wk after end of a specific chemotherapy cycle; 6–8 wk or longer after radiation therapyAt least 2 wk after end of last chemotherapy cycle; 6-8 wk after surgery; 12 wk after radiation