Consensus Recommendations for the Use of 18F-FDG PET as an Indicator of Therapeutic Response in Patients in National Cancer Institute Trials

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FIGURE 1.
Tissue time–activity curves for 10 patients with solitary pulmonary nodules imaged over time with dynamic emission PET (23). Lesions were identified, ROI analysis performed, and SUV determined. ¹⁸F-FDG uptake plateaued at various times after injection. Reprinted with permission from the Society of Nuclear Medicine.
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FIGURE 2.
Tissue time–activity curves for 16 patients. Static PET was performed at 1, 3, and 5 h after injection of ¹⁸F-FDG, and activity in lesions was determined. ¹⁸F-FDG uptake plateaued at various times after injection and, in several lesions, was still increasing even at 5 h after injection. (Courtesy of Karen Kurdziel.)

TABLE 1

Methods of Assessing ¹⁸F-FDG Uptake (1)

Method	Advantage	Disadvantage	Dependency
Visual	Static/whole-body imaging	Subjectivity	Uptake time
	No need for blood sampling	Chance of threshold variation between readers	Blood glucose concentration
	Short scan times	Low statistics	Partial-volume effects
	± Attenuation correction	Single snapshot of dynamic process
		Dependency on background activity
SUV	Static/whole-body imaging	Numerous methods of calculation	Uptake time
	Semiquantitative analysis	Low statistics	Blood glucose concentration
	No need for blood sampling	Single snapshot of dynamic process	Body weight
	Ease of computation	Need for attenuation correction	Partial-volume effects
		Inaccuracy in detecting small changes
Kinetic	Dynamic data acquisition	Need for input function (arterial preferred)	Partial-volume effects
	Quantitative analysis	Complexity of computation	Quality of input function
	Low dependency on imaging time

TABLE 2

Recommendations of Workshop Panel

Parameter	Recommendation
Patient preparation	Patients fast overnight for morning scan or 4 h for afternoon scan. Venous serum glucose concentration is measured before injection (<120 mg/dL for nondiabetic patients and 150–200 mg/dL for diabetic patients).
	Diabetic patients are scanned in morning after overnight fast and before first use of medication.
	Patients are well hydrated and, if possible, drink 500 mL of water after injection and before scanning. For renal/pelvic imaging, furosemide (20–40 mg) may be given 10–15 min after ¹⁸F-FDG injection, or urinary catheter may be used.
	All medications being taken by patients are recorded.
	Diazepam or other mild sedative may be used at clinician's discretion to decrease uptake in muscle.
PET timing	Pretreatment and posttreatment scans are acquired.
	Pretreatment scans are acquired as close to start of therapy as possible (preferably <2 wk).
	Posttreatment scans are acquired no sooner than 2 wk after end of chemotherapy to avoid transient increases or decreases. Timing is determined by endpoint being assessed.
	Timing of scans after changes due to radiotherapy needs further investigation.
	Whole-body imaging begins 60 ± 10 min after injection of ¹⁸F-FDG.
Attenuation correction	Attenuation correction is used. No standard procedure has yet been recommended. Procedure chosen is documented.
¹⁸F-FDG dose	No standard dose has yet been recommended. Doses of 370–740 MBq (10–20 mCi) are appropriate. Dose injected is documented.