Background: The purpose of this study was to investigate the incidence and prognostic value of retropharyngeal lymphadenopathy in nasopharyngeal carcinoma patients using contrast enhanced computed tomography (CT).
Methods: From January 1989 to December 1991, 364 patients with newly diagnosed nasopharyngeal carcinoma without distant metastasis had a baseline CT performed. All patients had radiotherapy as their primary treatment. Eighty-seven patients also received neoadjuvant chemotherapy for locally advanced disease. All patients with clinical N0 disease had prophylactic lymph node irradiation. The contrast enhanced CT given prior to all treatment was evaluated for the presence of retropharyngeal lymphadenopathy. Criteria for involved lymph nodes included a lymph node size of 10 mm or more, the presence of central necrosis within the lymph node, or the presence of a contrast enhancing rim.
Results: The incidence of retropharyngeal lymphadenopathy was 29.1%. A higher incidence of retropharyngeal lymph node involvement was observed in Ho's T2/T3 disease compared with T1 disease, and a higher incidence was also found in patients with cervical lymph node disease compared with those with clinical N0 disease. No significant differences in relapse free survival rates, local control rates, lymph node control rates, or distant failure rates were observed between patients with or without retropharyngeal lymphadenopathy after adjusting for T and N classifications. In 134 patients with clinical N0 disease, retropharyngeal lymphadenopathy was found in 21 patients, whereas 113 had no evidence of retropharyngeal lymphadenopathy. However, no significant difference in treatment outcome was observed between the two groups.
Conclusions: Using CT imaging, the presence of retropharyngeal lymphadenopathy in patients with nasopharyngeal carcinoma does not appear to affect the prognosis. In patients with clinical N0 disease, the identification of retropharyngeal lymphadenopathy based only on CT imaging is not sufficient evidence for an N1 classification.