Chordoma should be included in the differential diagnosis of a dumbbell-shaped mass involving upper cervical vertebrae i若病人在上颈椎呈现哑铃状肿块及患有长期症状时，脊索瘤应列入鉴别诊断中。
with open fields or with the 0° wedge,9% isodose curve couldn't cover the postzone of pharyngolargnycal or the prozone o不加楔形板、加0°楔形板时,9%的等剂量曲线不能覆盖部分咽喉后部、颈椎椎体前缘,C I低;