Usefulness of PET/CT in diagnosing cervical lymph node metastasis in head and neck squamous cell carcinoma

In recent years, there have been some reports stating that PET/CT is useful in diagnosing cervical lymph node metastasis in head and neck squamous cell carcinoma. We also use PET/CT in our department to determine N classification before treatment. We examined the usefulness of PET/CT in diagnosing cervical lymph node metastasis by comparing preoperative PET/CT images and postoperative pathological diagnosis of the patients who underwent neck dissection in our department. The subjects were 42 patients(59 sides)who underwent neck dissection within one month after PET/CT was performed and did not receive preoperative treatment such as induction chemotherapy. Among 23 sides diagnosed as positive for metastasis by preoperative PET/CT, metastatic lymph nodes were recognized in 19 sides in postoperative pathological diagnosis. Meanwhile, among 36 sides diagnosed as negative for metastasis by PET/CT, no metastatic lymph nodes were observed in 33 sides in postoperative pathological diagnosis. With the sensitivity at 86% and the specificity at 89%, PET/CT was considered useful in diagnosing cervical lymph node metastasis, however, attention needs to be paid to false-positive or false-negative cases.