Limitations of PET/CT in Detecting Cervical Lymph Node Metastases in Betel Nut Induced Oral Cancer

Objective: Limited research has been done previously in examining the utility of PET/CT in the preoperative staging of betel nut associated OSCC (BNOSCC). This study was conducted to evaluate the relationship between the standardized uptake values (SUV) of lymph nodes via FDG-PET/CT and their corresponding pathological specimens in betel nut chewers. Study design: Retrospective review. Setting: Single-institution academic center. Methods: A retrospective review of patients with BNOSCC seen at the Tipler Army Medical Center (TAMC) Head and Neck Surgery clinic from October 2004 to October 2019 was conducted. Preoperative FDG-PET/CT images were analyzed for the SUVmax of regional lymph nodes, with a node positive for malignancy defined as >3. The extent of disease spread predicted by FDG-PET/CT was then compared to the postoperative histopathological results. Results: Among patients with BNOSCC, FDG-PET/CT was found to significantly overpredict the extent of lymph node involvement identified on pathological analysis. Metabolic activity of lymph nodes was significantly overestimated on preoperative imaging. These findings highlight a clear discrepancy between the sensitivity and specificity of FDG-PET/CT found in BNOSCC and that in non-betel nut related disease. Conclusion: Elevated false-positive rates for LN positivity on FDG-PET/CT have been observed in BNOSCC patients. This finding could potentially lead to upstaging, and lead to excessive, more invasive treatment courses and interventions. This is a phenomenon that Head and Neck surgeons should be cautious about when working with BNOSCC patients. Level of evidence: 3.