The value of PET/CT to assess clinically negative necks.

The aim was to evaluate the efficacy of [(18)F]-2-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in evaluating metastasis of head and neck squamous cell carcinoma (HNSCC) to the cervical lymph nodes, with specific attention to the efficacy in regard to clinically negative necks. This was a retrospective review of 243 patients with HNSCC between years 2005 and 2007 treated at a comprehensive cancer care institution who underwent pre-operative PET/CT and neck dissection with either an N0 (112 patients) or N+ (131 patients) clinical nodal status. PET/CT findings were correlated with histopathological results of surgical specimens. A majority of the primary sites were oral cavity and oropharynx (70%), followed by larynx, unknown primary and hypopharynx. In the group of 112 patients who underwent 144 neck dissections with N0 nodal status, sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) and accuracy were 57, 82, 59, 80 and 74%, respectively. In the group of 131 patients who underwent 169 neck dissections with N+ nodal status, sensitivity, specificity, PPV, NPV and accuracy were 93, 70, 96, 58 and 91%, respectively. PET/CT has a much reduced rate of efficacy for the clinically negative neck compared to the clinically positive neck. PET/CT in its current stage does not appear to offer an advantage in staging the clinically N0 neck due to high rates of false positives and negatives.