목적: Pathologic extranodal extension (ENE) in metastatic lymph node is associated with poor prognosis for head and neck squamous cell carcinoma (HNSCC).Prognostic role of ENEdetected in preoperative CT (cENE) studies has not been studiedwell. This study was to investigate the prognostic value of cENEdetected in HNSCC patients treated with concurrent chemoradiation therapy (CCRT). 방법:We reviewed medical records of 117 patients with HNSCC and underwent CCRTcompletely with accessible pretreatment CT reports. They composed of oropharynx cancer (n =58 ), larynx cancer (n =24 ), and hypopharynx cancer (n =35 ) Criteria used for cENE included a thick-walled, enhancing nodal margin loss of outer nodal margin definition infiltration of the adjacent fat planes around portion of the node.We divided the enrolled patients into two groups according to cENE. We evaluated survival rate of each group and analyzed prognostic factors. 결과:Median follow-up was 37.4months. cENE(+) group (n = 30) and cENE (-) group (n = 87 patients). 8 patients (6.8%) died and 21 (17.9 %) had disease recurrence. cENE (+) group presented worse 5 year overall survival (79.4%vs97.7 %, P = 0.001) and disease free survival (62.1%vs 88.4%, p =0.001) compared to cENE (-) group. Among clinical factors, cENE affect overall survival (OR = 10.298 , 95% confidential interval (CI) 3.861 27.466, P < 0.001). cENE affect disease free survival (OR = 6.461 , 95% confidential interval (CI) 2.980 14.011, P < 0.001) 결론:Pretreatment cENE predict treatment response of CCRT and guideand may help to determine the treatment modality for HNSCC.