[Clinical value of 18F-fluoro-2-deoxy-D-glucose positron emission tomography in detecting recurrent nasopharyngeal carcinoma at the parapharyngeal space after radiotherapy].

OBJECTIVE: To explore the significance of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) in the diagnosis of the recurrence or fibrosis of nasopharyngeal carcinoma at the parapharyngeal space after radiotherapy. METHODS: Thirty-two patients having received radiotherapy for nasopharyngeal carcinoma at the parapharyngeal space underwent 18FDG-PET in parallel with CT and magnetic resonance imaging (MRI) examinations to detect the recurrence or fibrosis of the tumors after the treatment, when the latter two examinations had failed to yield definite results. After all the imaging examinations, CT-guided puncture biopsy was performed in each case to observe the sensitivity, specificity and accuracy of the examinations. RESULTS: The sensitivity, specificity and accuracy were 79.16%, 75.00%, and 78.13% respectively for CT examination, and were 83.33%, 87.50%, and 84.38% for MRI. 18FDG-PET had the best sensitivity, specificity and accuracy in detecting tumor recurrence, which were 95.83%, 87.50%, and 93.75% respectively. CONCLUSION: 18FDG-PET can be considered in cases of suspected recurrence of nasopharyngeal carcinoma at the parapharyngeal space after radiotherapy, and CT and MRI examinations either used alone or in combination may also reach definite diagnosis with the help of CT-guided biopsy.