Diagnostic Accuracy of Up-Front PET/CT and MRI for Detecting Cervical Lymph Node Metastases in T1-T2 Oral Cavity Cancer-A Prospective Cohort Study.

The diagnostic accuracy of up-front 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for detecting cervical lymph node metastases in patients with T1-T2 oral squamous cell carcinoma is reported with large discrepancies across the literature. We investigated the sensitivity, specificity, positive and negative predictive value, and accuracy of up-front PET/CT for detecting cervical lymph node metastases in this patient group and compared the performance to magnetic resonance imaging (MRI). In this prospective cohort study, 76 patients with T1-T2 oral squamous cell carcinoma underwent an up-front PET/CT and MRI at the Odense University Hospital from September 2013 to February 2016. Sentinel node biopsy and elective neck dissection were used for histopathological verification of the imaging modalities. Up-front PET/CT was significantly more sensitive than neck MRI (74% vs. 27%, = 0.0001), but less specific (60% vs. 88%, = 0.001). The accuracy of PET/CT and neck MRI was comparable (66% vs. 63%, = 0.85), the PPV was slightly in favor of neck MRI (56% vs. 62%, = 0.73), the NPV was slightly in favor of PET/CT (77% vs. 63%, = 0.16). Neither PET/CT nor neck MRI should stand alone for N-staging T1-T2 oral cavity cancer.