鼻咽癌咽旁间隙侵犯调强放疗临床分析

Clinical analysis of IMRT in nasopharyngeal carcinoma with poststyloid space involvement

目的比较鼻咽癌茎突后间隙侵犯调强放疗与常规放疗对预后的影响。方法将78例鼻咽癌患者分为常规放疗组40例和调强适形放疗组38例,常规放疗采用面颈联合野,两侧成角耳前野,耳后野,总剂量DT 70～74 Gy,调强放疗采用7个野照射,大体肿瘤GTV 69～73 Gy,对3年局控率﹑生存率﹑无远处转移生存率进行分析评价。结果所有患者随访均达到3年,常规放疗组3年局控率、生存率﹑无远处转移生存率分别为57.5%(23/40)、60.0%(24/40)、55.0%(22/40),调强放疗组3年局控率﹑生存率﹑无远处转移生存率81.6%(31/38)、78.9%(30/38)、68.4%(26/38),两者局控率比较,差异有统计学意义(P=0.0213)。结论调强适形放疗能够提高鼻咽癌茎突后间隙侵犯患者的局控率,改善生存率,远处转移是治疗失败的主要原因。

Objective To compare the treatment effects between IMRT and conventional radiotherapy for Nasopharyngeal carcinoma （NPC） with post-styloid space involvement. Methods 78 cases of NPC with post-styloid space involvement were treated with conventional radiotherapy （40 cases ） and IMRT （38 cases）. Conventional radiotherapy were divided into two phases. The first 36-38 Gy were delivered by the opposed facial-neck fields, and the remaining 34-36 Gy were delivered through 5-10 degree posterior tilted facial fields or an add-on parapharyngeal space field boost of lO-15Gy after opposed facial fields were implemented. For IMRT cases, the post-styloid space was delineated as parts of gross tumor volume and prescribed to 70-74 Gy. Results The 3 year local control, overal survival and metastasis free survival were 57.5% （23/40）, 60.0% （24/40）and 55.0% （22/40） for conventional radiotherapy, and 81.6% （31/ 38）, 78.9% （30/38）and 68.4% （26/38） for IMRT respectively. The local control between two groups was stastical significant （ P =0. 0213）. Conclusion IMRT is superior to conventional radiotherapy in local con- trol for NPC with post-styloid space involvement.