We prospectively evaluated the sensitivity and specificity of (18)F-FDG PET in the detection of neck lymph node metastases in patients with oral cavity squamous cell carcinoma (OSCC). We also sought to evaluate whether pretreatment PET visual scores in the neck lymph nodes may improve risk stratification.
Methods: We enrolled 473 OSCC patients (445 men and 28 women; mean age ± SD, 50.9 ± 11.7 y) without distant metastases. All participants underwent (18)F-FDG PET within 2 wk before surgery and neck dissection. Histopathology was taken as the reference standard for neck lymph node status. The duration of follow-up was at least 24 mo in all surviving patients.
Results: (18)F-FDG PET correctly diagnosed 164 of 211 patients with neck metastases and 152 of 262 subjects without pathologic neck metastases, resulting in a patient-based sensitivity and specificity of 77.7% and 58.0%, respectively. In Cox models adjusting for age, sex, traditional risk factors, and treatment modality, PET results at the neck lymph nodes were significantly and independently associated with rates of neck control, distant metastasis, disease-free survival, disease-specific survival, and overall survival. Notably, the results of the c-statistics demonstrated that PET score improved the accuracy of risk prediction in terms of overall and disease-free survival rates.
Conclusion: PET findings at the neck lymph nodes have limited sensitivity and specificity for primary staging of OSCC but improve risk stratification beyond that of traditional risk factors.