Combined [18F]fluorodeoxyglucose positron emission tomography and computed tomography for detecting contralateral neck metastases in patients with head and neck squamous cell carcinoma

We evaluated the clinical utility of combined [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT), as well as CT and magnetic resonance imaging (MRI) in identifying nodal metastases in the contralateral neck in patients with head and neck squamous cell carcinoma (HNSCC). A total of 114 patients were preoperatively evaluated with PET/CT and CT/MRI. Histopathologic analysis from bilateral neck dissection tissues was used as the gold standard in assessing these imaging techniques. Of the 114 patients, 63 (55%) had neck metastases and 26 (23%) had contralateral neck metastases. On a per-level basis, FDG PET/CT was significantly more sensitive and accurate than CT/MRI in the ipsilateral (88% vs. 70%, P < 0.01 and 93% vs. 89%, P < 0.01, respectively) and contralateral (52% vs. 36%, P < 0.01 and 91% vs. 90%, P = 0.039, respectively) neck. PET/CT and CT/MRI were less sensitive in detecting contralateral than ipsilateral neck metastases due to the lower incidence of metastases and smaller nodes on the contralateral side. Combined PET/CT is superior to CT/MRI in detecting metastatic neck nodes in HNSCC patients. However, PET/CT may not abrogate the need for contralateral neck surgery or radiotherapy in these patients.