Compare the diagnostic values of head and neck dedicated PET / CT and whole body PET / CT (n = 84) Protocols Diagnostic values Head and neck dedicated PET / CT Whole body PET / CT Sensitivity (%) 93.7 90.9 Specificity (%) 76.2 66.7 Positive predictive value (%) 92.2 95.2 Negative predictive value (%) 80 50 False positive rate (%) 23.8 33.3 Falsenegative rate (%) 6.3 9.1 Accuracy (%) 89.3 88 18 Remarks: - Head and neck dedicated PET / CT had 93.7% sensitivity, 76.2% specificity, 80% negative predictive value and 89.3% accuracywhich were higher than that of whole body PET / CT (90.9%; 66.7%; 50% and 88%, respectively).