The value of preoperative 18F-FDG PET/CT for the assessing contralateral neck in head and neck cancer patients with unilateral node metastasis (N1-3).

OBJECTIVES: The purpose of this study was to determine whether preoperative (18) F-FDG PET/CT is useful in assessing contralateral lymph node metastasis in the neck. DESIGN: A retrospective review of medical records was performed. SETTING: Patients treated at a single institute. PARTICIPANTS: One hundred and fifty-seven patients whose pathology results were positive for unilateral node metastasis (N1-3) involvement and underwent preoperative (18) F-FDG PET/CT for head and neck squamous cell carcinoma (HNSCC) were reviewed. MAIN OUTCOME MEASURES: Prognostic factors and nodal SUVmax were studied to identify the risk of contralateral disease. RESULTS: Thirty-six (22.9%) patients had contralateral cervical lymph node metastases. The (18) F-FDG PET/CT had a sensitivity of 80% and a specificity of 96% in identifying the contralateral cervical lymph node metastases on a level-by-level basis. The median SUVmax values of the ipsilateral and contralateral lymph nodes were 3.99 ± 3.36 (range, 0-20.4) and 2.94 ± 2.04 (range, 0-8.7), respectively (P = 0.001). There was a significant difference in the median SUVmax of contralateral nodes between the benign and malignant cervical lymph nodes (2.31 ± 0.62 versus 3.28 ± 2.43, P = 0.014). The cut-off value of contralateral median SUVmax in the context of contralateral cervical metastasis was 2.5 with the sensitivity of 75% and the specificity of 94%. A median contralateral lymph node SUVmax  ≥ 2.5 was associated with 5-year disease-specific survival (P = 0.038). CONCLUSION: (18) F-FDG PET/CT median SUVmax cut-off values of contralateral lymph nodes ≥2.5 were associated with contralateral cervical lymph node metastases and 5-year disease-specific survival in HNSCC patients with unilateral metastases.