Positron emission tomography in the evaluation of the negative neck in patients with oral cavity cancer

Objective: Proper management of the clinically negative neck (N0) in patients with squamous cell carcinoma (SCC) of the oral cavity (OC) is controversial. Detecting cervical metastasis in these patients is important, because cervical lymph node metastasis is associated with an unfavourable prognosis. Conventional radiographic studies, such as computerized tomography (CT) and magnetic resonance imaging (MRI), may augment physical examination. However, there are still limitations of these modalities in detecting the presence of metastatic cervical disease. Positron emission tomography (PET) is a functional imaging modality that has recently been used in patients to detect head and neck neoplasms. We report using PET in the evaluation of the N0 neck in 11 consecutive patients with SCC of the OC who underwent neck dissection. Method: The results of PET scans were correlated with the pathologic findings of 19 neck dissections. Results: Four patients (36%) undergoing 7 neck dissections (37%) had pathologic evidence of disease. Positron emission tomography scans were positive in all of these patients and in all pathologically confirmed cervical metastasis. Seven patients (64%) undergoing 12 neck dissections (63%) had no pathologic evidence of cervical metastasis. Positron emission tomography scans were negative for malignancy in all of these seven patients. In the patient with SCC of the OC with a clinically N0 neck, we found PET to have an overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%. Computerized tomography demonstrated 40%, 88%, 67%, 70%, 69%, respectively. In all statistical categories except specificity (p = .1), PET demonstrated statistical significance (p < .05) over CT. Conclusion: Positron emission tomography appears to be a promising diagnostic aid that may be applied when evaluating the N0 neck for patients with SCC of the OC.