18-fluoro-2-deoxyglucose positron emission tomography in detecting residual/recurrent nasopharyngeal carcinomas and comparison with magnetic resonance imaging.

Abstract

It is known that 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is effective in the early detection of residual/recurrent nasopharyngeal carcinomas (NPC). To compare FDG-PET with the conventional magnetic resonance imaging (MRI) for the detection of residual/recurrent NPC, the authors studied 67 follow-up cases of patients with NPC using both FDG-PET and MRI. From February 1997 to February 2001, 67 NPC patients (14 women, 53 men; age range, 16-67 years; mean age, 46.6 +/- 12.5 years) were recruited. Both FDG-PET and MRI of the head and neck area for each patient were performed at least 4 months (duration range, 4-70 months; mean, 14 +/- 13.5 months) after radiotherapy or radiotherapy with concurrent chemotherapy. The final diagnosis was confirmed by biopsy or clinical follow-up for at least 6 months. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of FDG-PET images were 100%, 93.4%, 95.5%, 87.5%, and 100%, respectively. In contrast, the sensitivity, specificity, accuracy, PPV, and NPV of the MRI scans were 61.9%, 43.5%, 49.3%, 33.3%, and 70.0%, respectively. The results of the current study suggest that FDG-PET is much more effective than MRI in detecting residual/recurrent NPC.