Nasopharyngeal Carcinoma: Evaluation With CT

Objectives The purpose of this study is to recognize tumor spreading patterns at the primary sites and in cervical lymph nodes of NPC (nasopharyngeal carcinoma) on the initial CT scans and to demonstrate the different patterns of tumor regression on the follow-up scans after radiation therapy, and further more, to try to predict the recurrence risk according to the CT manifestations of the patterns. Materials and methods CT scans of 1100 patients with histologically proven NPC, who were treated mainly with radiation therapy in our hospital from Jan 1990 to Dec 2005 with intact clinical and imaging files, were retrospectively reviewed by two experienced radiologists. Those patients included 807 men and 293 women with age ranging from 11 to 85 year (median 48 years). The location and extension of the primary tumors on the initial CT scans, especially whether or not and in which way the tumors involved in the skull base or grew into any of the adjacent neck spaces, and the metastatic lymph nodes' distribution and manifestations were carefully evaluated. The tumors' response to the radiation therapy and the manifestations of recurrent tumors on the follow-up scans were also reviewed. Tumor spreading patterns and staging before treatment as well as their prognostic significance were evaluated. All the data were statistically processed with SPSS 11.5 software.Results The tumor spreading patterns of the 1100 cases were classified into 3 types. 336 cases (30.54%) were type 1 , superficial growing type, which means that tumor was confined to the nasopharyngeal cavities. 317 (28.82%) cases were type 2, adjacent invasion type, which was defined as that the tumors only invaded the adjacent spaces. 447 cases (40.64%) belonged to type 3, ultra-cavity invasive type, which...