10:48 AM: Utility of Panendoscopy for Unknown Primary and Negative PET

FDG-PET and PET/CT - Part II

“…In such cases, FDG-PET and PET/CT can help identify the primary malignant lesion [ Figure 5 ] in about 25% of cases. [ 13 14 ] At our center, a retrospective chart review revealed that using FDG-PET, we were able to identify the primary tumor in 61% of patients (14 of 23 cases) who presented with this scenario[ 15 ] with a very high negative predictive value (89%). Our higher rate of detection of the occult primary lesion may be attributable to several factors, including rigorous scan protocol (valium pre-treatment oral and intravenous hydration, 90-min delayed imaging), experienced readers, interpretations tuned to increase sensitivity (but not specificity) in this situation [ Figure 5 ] and a relatively small number of patients in this study.…”