摘要头颈部肿瘤患者放疗过程中,部分腮腺不可避免地被包在计划靶体积(PTV)中,使得此部分腮腺接受与PTV同样剂量的照射.在放疗过程中由于受患者年龄、初始腮腺体积、接受10～ 40 Gy剂量照射的腮腺体积(V10-40)、患者体重、体厚及腮腺平均受照剂量等的影响使得放疗中腮腺体积最多可缩小至原体积的50％左右,并向体中线处移动,结果腮腺所受实际照射剂量高于处方剂量,造成腮腺分泌功能降低,发生严重口腔干燥症,大大影响患者日后生活质量.

abstractsDuring radiation for head and neck cancers,part of parotids are contained in planning target volume(PTV),which lead to parotids receiving radiation as the same as PTV.Radiation for head and neck cancers will influence the parotids.In the period of radiation,many factors will influence parotids,such as age,primary parotid volume,V10-40,weight and mean radiation dose et al.These factors will result in that the parotid volume reduces nearly 50％ and moves toward the middle line of the body.As a result,the real dose of the parotid receiving is higher than prescription dose.The excretion function of the parotid will be severely damaged after radiation,which will lead to xerostomia and influence the quality of patients life.