Background: We investigated the utility of clinical FDG-PET in patients with nasopharyngeal tumor treated by radiotherapy, retrospectively.
Materials and methods: Fifteen patients with known or suspected nasopharyngeal tumors underwent FDG-PET. PET images were evaluated with visual interpretation qualitatively. Semiquantitative analysis was also performed on the metabolic ratios (MRs).
Results: The sensitivity and specificity of FDG-PET based on visual inspection were 92.9% (13/14) and 83.3% (10/12), respectively. There was a statistically significant difference between histological types in the mean MR. MR was significantly decreased by radiotherapy in patients with poorly differentiated squamous cell carcinoma. PET scans obtained 1-3 months after radiotherapy indicated decreased levels of FDG uptake in all tumors but one scan did not accurately reflect the status of the disease.
Conclusion: These results are encouraging as to the clinical usefulness of FDG-PET for evaluating radiation effects in patients with nasopharyngeal tumor.