18f-fluorodeoxyglucose positron emission tomographycomputed tomography for diagnosis of cervical lymph node metastases of oral squamous cell carcinoma

Ob:18F-Fluorodeoxyglucose positron emission tomography-computed tomography is increasingly being used for the diagnosis of primary malignant tumours, cervical lymph node metastases, and distant metastases. As cervical lymph node metastasis is a particularly important prognostic factor for patients with cancers of the head and neck, this study was performed to ascertain the efficacy of this technique for the diagnosis of such metastases in patients with oral squamous cell carcinoma. Patients and Methods: 123 cervical lymph nodes were analysed from 21 patients, who underwent preoperative diagnosis by 18F-fluorodeoxyglucose positron emission tomography-computed tomography in addition to other conventional diagnostic procedures, such as computed tomography and magnetic resonance imaging. Lymph nodes were removed by sentinel lymph node biopsy or neck dissection and were examined histopathologically for metastasis. Results: Seven patients were metastasis-positive. The optimal cut-off for the maximum standardised uptake value for 18F-fluorodeoxyglucose positron emission tomography-computed tomography in assessing lymph node metastases was 4.1, which had the highest diagnostic accuracy (sensitivity, 100%; specificity, 100%; accuracy, 100%). Of the 13 lymph nodes identified as metastasis-positive by histological examinations, 12 (92.3%) also tested positive using 18F-fiuorodeoxyglucose positron emission tomography-computed tomography. Conclusion: These results suggest that 18F-fluorodeoxyglucose positron emission tomographycomputed tomography is useful for detecting cervical lymph node metastasis.