Differentiation of benign and malignant nasopharyngeal lesions based on FDG uptake on PET/ CT: comparison with pathology

Abstract

Objective: The value of incidental fluorine 18-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computerized tomography (PET/CT) in patients who undergo subsequent nasopharyngeal biopsy for suspected nasopharyngeal malignancy has not been assessed. The purpose of this study was to determine the ability of FDG maximum standardized uptake value (SUVmax) on PET/CT to differentiate between benign processes and malignant nasopharyngeal lesions. Methods: We retrospectively reviewed the medical records of 92 patients who underwent FDG PET/CT for diseases other than nasopharyngeal cancer with subsequent endoscopic nasopharyngeal biopsy. Receiver operating characteristic (ROC) curve analysis was used to define a cut-off for the differentiation of benign processes from malignant lesions with incidental increased FDG uptake. Results: All 92 patients had incidental FDG uptake (SUVmax≥3). Compared with routine pathological analysis, this analysis demonstrated an SUVmax cut-off of 6.5, resulting in an area under the ROC curve of 0.74 (95% confidence interval, 0.63-0.82), sensitivity of 88.8%, and specificity of 63.8% for the detection of malignant nasopharyngeal lesions. Conclusion: If a nasopharyngeal lesion has intense FDG uptake on PET/CT (SUVmax≥6.5), malignancy should be strongly suspected.