CAJ | 학술논문

目的探讨RapidArc联合主动呼吸控制(ABC)技术在胸段食管癌调强放疗的剂量学特点.方法选取10例接受放疗的胸段食管癌患者,在ABC辅助下选择吸气末屏气触发方式(mDIBH),触发阈值设定为呼吸曲线峰值的80％,和自由呼吸(FB)状态下分别行定位CT扫描,应用三维治疗计划系统为每例患者设计FB下的IMRT(IMRT-FB)和双弧RapidArc( Arc-FB)、mDIBH下的3个小弧RapidArc( Arc-A BC)3种调强放疗计划.评价靶区的D2％、D98％、V95,均匀指数(HI)和适形指数(CI),正常组织的相关剂量体积参数Vx,以及总机器跳数(MU)、总控制点数( control points)和治疗时间.结果 PTV的平均体积由FB下的376 cm3减少到了mDIBH下的260cm3.mDIBH下的双肺平均体积为5964.6 cm3,而FB则为3838.8 cm3,增加了35％；mDIBH和FB状态下平均心脏体积分别为524.4和642.7 cm3.Arc-ABC计划靶区的CI、HI及D2％、D98％、V95与IMRT-FB和Arc-FB计划差异无统计学意义,双肺的V10、V20、V30、V40及平均剂量(Dmean)明显低于IMRT-FB和Arc-FB(F=4.38、5.34、4.07、3.89、4.28,P＜0.05),心脏的V20、V30、V40、Dmean及脊髓Dmax有不同程度的下降,但差异无统计学意义.Arc-ABC计划的总机器跳数和子野数也明显少于IMRT-FB计划(F=26.86、12.56,P＜0.05).结论 RapidArc联合ABC在胸段食管癌精确放疗中具有提高靶区剂量和降低肺组织受照剂量的作用.
목적 탐토RapidArc연합주동호흡공제(ABC)기술재흉단식관암조강방료적제량학특점.방법 선취10례접수방료적흉단식관암환자,재ABC보조하선택흡기말병기촉발방식(mDIBH),촉발역치설정위호흡곡선봉치적80％,화자유호흡(FB)상태하분별행정위CT소묘,응용삼유치료계화계통위매례환자설계FB하적IMRT(IMRT-FB)화쌍호RapidArc( Arc-FB)、mDIBH하적3개소호RapidArc( Arc-A BC)3충조강방료계화.평개파구적D2％、D98％、V95,균균지수(HI)화괄형지수(CI),정상조직적상관제량체적삼수Vx,이급총궤기도수(MU)、총공제점수( control points)화치료시간.결과 PTV적평균체적유FB하적376 cm3감소도료mDIBH하적260cm3.mDIBH하적쌍폐평균체적위5964.6 cm3,이FB칙위3838.8 cm3,증가료35％；mDIBH화FB상태하평균심장체적분별위524.4화642.7 cm3.Arc-ABC계화파구적CI、HI급D2％、D98％、V95여IMRT-FB화Arc-FB계화차이무통계학의의,쌍폐적V10、V20、V30、V40급평균제량(Dmean)명현저우IMRT-FB화Arc-FB(F=4.38、5.34、4.07、3.89、4.28,P＜0.05),심장적V20、V30、V40、Dmean급척수Dmax유불동정도적하강,단차이무통계학의의.Arc-ABC계화적총궤기도수화자야수야명현소우IMRT-FB계화(F=26.86、12.56,P＜0.05).결론 RapidArc연합ABC재흉단식관암정학방료중구유제고파구제량화강저폐조직수조제량적작용.
Objective To compare and analyze the dosimetric characteristics of the intensity-modulated arc therapy (RapidArc) combined with active breathing coordinator (ABC) in the thoracic esophageal carcinoma radiation therapy. Methods Ten thoracic esophageal carcinoma patients undergoing radiotherapy were selected for this study.The CT simulations were performed under three breath patterns respectively:moderate deep inspiration breath-hold (mDIBH) with ABC aid; Set the trigger threshold to 80％ of the peak of the respiration curve; and free breathing (FB).Based on the corresponding CT image sets,three treatment plans were generated for each patient respectively:Arc-ABC( three small arcs),ArcFB (consisted of two coplanar full arcs) and IMRT-FB plan.The following dosimetric parameters were compared among different plans:D2％,D98％,V95,homogeneity index ( HI),conformal index ( CI ) the percentage of volume receiving dose of over x Gy (Vx),monitor unit (MU),control points and treatment time.Results The planning target volume ( PTV ) of FB was 376 cm3 which decreased to 260 cm3 after using ABC.For mDIBH and FB patients,the total lung volumes were 5964.6 cm3(35％ more than FB) and 3838.8 cm3 respectively; the heart volumes were 524.4 cm3 and 642.7 cm3 respectively. No significant difference was observed among Arc-ABC,IMRT-FB and Arc-FB in terms of D2,D98,V95,CI and HI.For Arc-ABC plans,there were significant decreases of radiation dose in total-lung's V10,V20,V30,V40 and mean lung dose ( F =4.38,5.34,4.07,3.89,4.28,P ＜0.05).Various dose decreases of heart V20,V3,V40,Dmean and spinal cord Dmax were observed,yet no statistically significant difference existed.The MUs and total control points of Arc-ABC plans were significantly lower than other plans ( F =26.86,12.56,P ＜ 0.05 ).Conclusions When thoracic esophageal carcinoma patients were treated with radiotherapy,the combined utilization of RapidArc and ABC can potentially decrease the volume of irradiated lung yet escalate the dose in target.