Limitation of 1999 image-based nodal classification of the neck in nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the limitation of image-based classification and delineation of cervical nodes proposed in 1999. Methods 259 consecutive nasopharyngeal carcinoma patients received contrast-enhanced transverse CT scan from July to November in 2003, the scanning range extended from the skull base to the inferior border of the clavicle, with thickness set at 5?mm per slice from the skull base to the oropharynx, and 1?cm per slice from the oropharynx to the clavicle. Interpretation of the images and assessment of the involved nodes distribution were performed by both radiation oncologists together with diagnostic radiologists according to 1999 image-based classification and delineation of the neck. Then we evaluated whether this classification could fully cover all the lymphatic drainage areas of the neck. Results 218 cases had nodal involvements. Nodal distributions were 0 in levelⅠA, 6 in levelⅠB, 136 in level ⅡA, 171 in level ⅡB, 78 in level Ⅲ, 20 in level Ⅳ, 33 in level VA, 27 in level VB,0 in level Ⅵ and Ⅶ, 5 in supraclavicle and 102 in retropharyngeal space, respectively. Among another 57 cases who belonged to none of the above levels, 2 cases had lesions in the preauricular area, the rest 55 medial to the border of internal carotid artery, 2?cm from inferior to the skull base to the hyoid bone. Conclusions The 1999 image-based classification of the neck nodes,being essentially rational, did not fully cover the retropharyngeal space. It would be better to shift the inferior boundary of the retropharyngeal space to the level of the hyoid bone.