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华西医学  2010 

图像引导下鼻咽癌放射治疗中颈部变形旋转误差研究

, PP. 2147-2150

Keywords: 锥形束CT,鼻咽癌,变形误差

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Abstract:

【】 目的 利用不同匹配区域对锥形束CT(CBCT)与定位CT(FBCT)分别配准,测量出鼻咽癌放射治疗中颈部的变形误差。 方法 分析2007年4月-2008年12月收治鼻咽癌患者23例,调整治疗床前198次CBCT扫描。将鼻咽部扫描CBCT图像匹配区域分为上下两个区域进行对比分析。其中上匹配区域为上界为蝶窦上缘,下界为颈4下缘,侧界包括下颌骨外轮廓,前界为上颌窦1/2,后界为平棘突后缘;下匹配区域为上界约颈4下缘,下界约胸2-3下缘,侧界包括椎体外轮廓,前界包括皮肤,后界平棘突后缘。匹配方式选择骨,比较匹配结果差异。 结果 选择上与下匹配区域结果除Y(头脚)方向旋转误差无统计学差异外,余均有统计学差异(P<0.05)。差值在X(左右)、Z(前后)、Y(头脚)方向平移分别为(1.14±2.80)、(0.47±1.41)、(0.58±3.88)mm,旋转误差X、Y、Z方向分别为(0.90±1.98)、(0.80±2.03)、(0.68±1.90)°。 结论 鼻咽癌放射治疗中颈部区域存在一定变形误差,通过CBCT引导发现变形误差并进行正确纠正是必须的,结合临床实际及靶区与危及器官的变化为重新计划提供依据。?【Abstract】 Objective Toinvestigatetherotationerrorsduetoneckdeformationinnasopharyngealcancer(NPC)radiotherapywithdifferentmatchareastoregisterconebeamCT(CBCT)fromimageguidingandfanbeam(FBCT)fromsimulation. Methods Atotalof198pre-correctionCBCTdatasetsfrom23NPCpatientsfromApril2007toDecember2008wereretrospectivelyanalyzed.ThematchingareasinCBCTimagesweredividedintoupanddownregionofinterest(ROI).FortheupROI,thesuperior,inferior,leftandright,anterior,andposteriorboundaryweresetparallelwithsphenoidsinusupside,C4downside,mandibleoutside,and1/2ofmaxillaryairsinusandacanthi.ForthedownROI,thelinesweresetparallelwithC4downside,T2-3downside,neckoutside,skinsurfaceandacanthirespectivelyinalldirections.Allregistrationswereperformedautomaticallybybonyanatomyandtheresultswerecompared. Results TheregistrationresultsbytheupandthedownROIshowedsignificantdifferenceexceptYdirectionforrotation.Thetranslationerrorwas(1.14±2.80),(0.47±1.41),and(0.58±3.88)mm,respectively;andtherotationerrorwas(0.90±1.98),(0.80±2.03),and(0.68±1.90)°inX,Y,andZdirection,respectively.〖WTHZ〗Conclusions〖WTBZ〗TherearesomesignificantdeformationerrorsatneckareasinNPCradiotherapy.ItisimportanttofindoutthedeformationandcorrectitwithCBCTimageguiding.Thiskindoferrorinformationmayprovidecluesforre-planninginadditiontoclinicalpracticeandthechangesofclinicaltargetsandinvolvedorgans.?

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