Limitations of Fluoro-2-deoxy-D-glucose—Positron Emission Tomography for Metastatic Neck Disease Secondary to Oral Squamous Cell Carcinoma

Objective: The objectives of this study were to evaluate the efficacy and limitations of fluoro-2-deoxy- D-glucose—positron emission tomography for metastatic neck disease secondary to oral squamous cell carcinoma. This study specifically examined the limitations of the procedure. Materials and Methods: From April 2004 to October 2007, 35 patients with oral squamous cell carcinoma underwent computed tomography, ultrasound, and fluoro-2-deoxy-D-glucose—positron emission tomography before treatment with neck dissection. After neck dissection, the results of computed tomography/ultrasound and positron emission tomography imaging were correlated with the histopathological findings of the cervical lymph nodes. Results: Positron emission tomography of the cervical lymph nodes was positive for 20 patients, 16 of who were demonstrated to have metastases on histopathological examination. Of the 4 falsepositive results, 3 were reactive lymphadenitis and 1 was sarcoidosis. Positron emission tomography was negative for 15 patients. Two of these patients had false-negative results, as metastatic disease was found at neck dissection. In 1 patient, the metastatic lymph node was largely keratinised, while micrometastasis was evident in the other patient. Pathological findings were compared with imaging results to determine the relative efficacies of positron emission tomography (accuracy, 82.9%; sensitivity, 88.8%; specificity, 76.5%), computed tomography (accuracy, 85.7%; sensitivity, 88.8%; specificity, 82.4%), and ultrasound (accuracy, 88.6%; sensitivity, 88.8%; specificity, 88.2%). There were no significant differences on statistical analysis. Conclusion: Positron emission tomography appears to have significant potential for the detection of lymph node metastasis. However, fluoro-2-deoxy-D-glucose—positron emission tomography should not be used as the sole method of imaging for initial investigation of oral squamous cell carcinoma and cervical lymph node metastasis. The surgical management of neck lymph node metastasis should not be based on fluoro-2-deoxy-D-glucose—positron emission tomography findings alone. Use of other imaging modalities in addition to fluoro-2-deoxy-D-glucose—positron emission tomography should increase the diagnostic accuracy over fluoro-2-deoxy-D-glucose—positron emission tomography alone.