CT检查对鼻咽癌设野的影响

INFLUENCE OF CT SCAN ON THE PORTAL DESIGN FOR NASOPHARYNGEAL CARCINOMA (NPC)

选取1991年7月～1992年6月单纯放疗的鼻咽癌病人120例,分析其放疗前CT图像,我们认为鼻咽癌累及咽旁间隙后区、口咽及前区完全填塞时有下行性生长倾向,最好采用面颈联合野;累及鼻腔者有向前上生长的倾向,鼻前野上半要包及后组筛窦;累及颅底者,要从入侵路径加量;累及前组颅神经者,多无颅底破坏,加量野可比正常颅底野低,以减少颅内受量,累及后组颅神经者,均有后区受累,设野要包及后区;为包及茎突内软组织。鼻前野面积最好采用7cm×7cm。

A retrospective analysis of the CT scan of 120 NPC patients treated solely by radiotherapy from 1991 to 1992 was done. The results showed that when the parapharyngeal spaces, both the anterior and posterior regions, together with the oropharynx are involved, a large confluent fasio-cer-vical portal is preferred as it has a tendency toword downward growth. As the invasion of the nasal cavity tends to extend upwards, the anterior nasal portal should encompass the posterior ethrhoidal cells. Those with invasion of the skull base, booster doses should be given to the invading route. For those with paralysis of the anterior cranial nerves, the booster portal could be set at a lower level than the skull base portal to reduce the in tra-cranial dose .