局部晚期直肠癌新辅助治疗同期加量调强与三维适形放疗随机对照研究

目的 评估局部晚期直肠癌新辅助治疗同期加量调强放疗对比三维适形放疗疗效及安全性。方法 前瞻性研究自2010年5月至2015年5月,临床分期为T₃/T₄或淋巴结阳性且肿瘤下缘距肛门10 cm以内初治直肠腺癌患者共130例。采用随机数字表法分为调强放疗组和三维适形放疗组,调强放疗组66例,三维适形放疗组64例。调强放疗方案为盆腔放疗剂量45 Gy,1.8 Gy/次,共5周,同步原发病灶及转移淋巴结外放1 cm加量放疗剂量至55 Gy。三维适形放疗为盆腔放疗45 Gy,1.8 Gy/次,共5周,两组于放疗第1~14天及第22~35天接受卡培他滨1 650 mg·m^-2·d^-1口服化疗。手术于放化疗结束后6~8周进行。结果 两组患者性别、年龄、肿瘤位置、病理分化程度以及临床分期基线指标差异均无统计学意义(P>0.05)。2例患者出现放疗终止情况,分别为调强放疗组1例3级腹泻与三维适形放疗组1例3级乏力。两组血液及非血液不良反应差异均无统计学意义,无4级及以上不良反应出现。手术类型及术后并发症两组差异均无统计学意义。术后4级病理降期(病理完全缓解)率调强放疗组为22.7%,三维适形放疗组为15.6%,两组比较差异无统计学意义(P>0.05),3级与4级病理降期率两组比例分别为42.4%和25.0%,两组比较差异有统计学意义(χ²=4.406, P=0.036)。结论 局部晚期直肠癌新辅助同期加量调强放疗为可行治疗方案,与三维适形放疗相比可进一步提高病理降期。临床试验注册 中国临床试验注册中心,ChiCTR-INR-16008004。     

食管癌同期推量调强放疗和后程缩野加量调强放疗的临床对比研究

目的 分析和比较食管癌同期推量调强放疗（SIB-IMRT）和后程缩野加量调强放疗（LCB-IMRT）的疗效。方法 回顾性分析2009年1月至2015年12月本院放疗五科收治的128例接受SIB-IMRT或LCB-IMRT技术的食管鳞癌患者的临床资料,采用倾向评分匹配法（propensity score matching,PSM）平衡SIB-IMRT组及LCB-IMRT组基本资料不均衡的变量,观察和比较两组的局部控制、生存、不良反应及首次失败方式。结果 匹配后两组共111例患者,全组1、3、5年局部控制率分别为83.6%、70.8%、66.0%,1、3、5年生存率分别为81.7%、46.3%、38.2%。SIB-IMRT组与LCB-IMRT组的1、3、5年局部控制率分别为81.6%、72.3%、68.5%和88.0%、67.6%、60.8%（P>0.05）;1、3、5年生存率分别为81.3%、51.7%、45.8%和82.4%、36.7%、26.7%（P>0.05）。两组≥ 3级的不良反应差异无统计学意义（P > 0.05）。全组共40例患者治疗失败,总失败率为36.0%,其中SIB-IMRT组失败率为33.8%（26/77）,LCB-IMRT组为41.2%（14/34）,两组比较差异无统计学意义（P>0.05）。全组局部失败占总治疗失败的65.0%。结论 食管癌SIB-IMRT和LCB-IMRT的不良反应相似,耐受性可;两组总的局部控制和生存无明显差异,但SIB-IMRT组有优于LCB-IMRT组的趋势,考虑SIB-IMRT技术更简便易行,中晚期食管癌放疗时采用SIB-IMRT技术可能是更好的选择。     

直肠癌术前放疗中三维适形放疗与调强适形放疗的剂量学比较分析

目的 比较三维适形放疗(3D-CRT)与5野、7野调强适形放疗(IMRT)的剂量分布,以探讨IMRT对直肠癌术前放疗的价值。方法 对10例术前新辅助放化疗直肠癌患者,分别设计3D- CRT、5野IMRT、7野IMRT计划,应用剂量体积直方图(DVH),比较3种治疗计划的靶区适形度指数(CI)、不均匀性指数(HI)和正常器官受量。结果 适形度指数(CI)7野IMRT计划＞5野IMRT＞3D- CRT,不均匀性指数(HI)5野IMRT计划＞7野IMRT＞3D- CRT。5野、7野IMRT计划比3D- CRT均可以减少高剂量照射小肠、膀胱、股骨头体积,7野IMRT计划比5野可以减少高剂量照射的骨髓和膀胱的体积。结论 直肠癌术前放疗中IMRT计划在靶区剂量适形度方面均优于3D- CRT计划,对正常组织的保护也存在明显的优势。7野IMRT计划较5野IMRT计划技术有更好的剂量适形度与剂量均匀性。     

直肠癌术前放疗中三维适形放疗与调强适形放疗的剂量学比较分析

Objective To compare the dose distribution of the three-dimensional conformal radiotherapy(3D-CRT)and 5-field or 7-field intensity modulated radiation therapy(IMRT), and to explore the value of IMRT in preoperative radiotherapy for rectal cancer.Methods Ten rectal cancer patients treated with preoperative combination radiotherapy and chemotherapy were enrolled in this study. 3D-CRT plan and the 5.field or 7-field IMRT plans were performed for each patient.The conformal index (CI),heterogeneity index(HI)of the planning target volume(PTV)and the dose of normal organs of 3D-CRT plan(3D-CRTp)and the 5-field or 7-field IMRT plans(IMRT5fp or IMRT7fp)were analyzed with the dose-volume histogram.Results The CI values of PTV were 0.91,0.87 and 0.78 in IMRT7fpIMRT5fp and 3D- CRT but with IMRT7fp>IMRT5fp>3D-CRTp(t=-5.69、-8.91,P<0.01),respectively.The HI values of PrV were 1.09,1.08 and 1.05 in IMRT5fp,IMRT7fp and 3D- CRTp but with IMRT5fp >IMRT7fp>3D- CRTp(t=3.41、-6.89,P<0.01),respectively.The ratio of dose volume were 0.08,0.10 and 0.19(t=2.79、3.52,P<0.05)in IMRT7fp,IMRT5fp and 3D- CRTp on the small intestine V50,with 0.07,0.10 and 0.19(t=2.58、3.40,P<0.05)in IMRT7fp,IMRT5fp and 3D-CRTp on the bladder V50 and 0.01,0.01 and 0.05(t=3.00、3.17,P<0.01)in IMRT7fp,IMRT5fp and 3D- CRTp on the fomoral head V45.The ratio of dose volume were 0.31 and 0.38(t=3.91,P<0.01)in IMRT7fp and IMRT5fp on the bone marrow V50,with 0.07 and 0.10 in IMRT7fp and IMRT5fp on bladder V45.Conclusions IMRT plan is superior to 3 D- CRT plan in dose conformal degrees of PTV with preoperative radiotherapy of rectal cancer and can significantly protect the normal tissues.The 7-field IMRT plan might be the optimal plan for dose conformal degree and dose uniformity compared with 5-field IMRT.     

直肠癌术前放疗中三维适形放疗与调强适形放疗的剂量学比较分析

Objective To compare the dose distribution of the three-dimensional conformal radiotherapy(3D-CRT)and 5-field or 7-field intensity modulated radiation therapy(IMRT), and to explore the value of IMRT in preoperative radiotherapy for rectal cancer.Methods Ten rectal cancer patients treated with preoperative combination radiotherapy and chemotherapy were enrolled in this study. 3D-CRT plan and the 5.field or 7-field IMRT plans were performed for each patient.The conformal index (CI),heterogeneity index(HI)of the planning target volume(PTV)and the dose of normal organs of 3D-CRT plan(3D-CRTp)and the 5-field or 7-field IMRT plans(IMRT5fp or IMRT7fp)were analyzed with the dose-volume histogram.Results The CI values of PTV were 0.91,0.87 and 0.78 in IMRT7fpIMRT5fp and 3D- CRT but with IMRT7fp>IMRT5fp>3D-CRTp(t=-5.69、-8.91,P<0.01),respectively.The HI values of PrV were 1.09,1.08 and 1.05 in IMRT5fp,IMRT7fp and 3D- CRTp but with IMRT5fp >IMRT7fp>3D- CRTp(t=3.41、-6.89,P<0.01),respectively.The ratio of dose volume were 0.08,0.10 and 0.19(t=2.79、3.52,P<0.05)in IMRT7fp,IMRT5fp and 3D- CRTp on the small intestine V50,with 0.07,0.10 and 0.19(t=2.58、3.40,P<0.05)in IMRT7fp,IMRT5fp and 3D-CRTp on the bladder V50 and 0.01,0.01 and 0.05(t=3.00、3.17,P<0.01)in IMRT7fp,IMRT5fp and 3D- CRTp on the fomoral head V45.The ratio of dose volume were 0.31 and 0.38(t=3.91,P<0.01)in IMRT7fp and IMRT5fp on the bone marrow V50,with 0.07 and 0.10 in IMRT7fp and IMRT5fp on bladder V45.Conclusions IMRT plan is superior to 3 D- CRT plan in dose conformal degrees of PTV with preoperative radiotherapy of rectal cancer and can significantly protect the normal tissues.The 7-field IMRT plan might be the optimal plan for dose conformal degree and dose uniformity compared with 5-field IMRT.     

中晚期宫颈癌患者调强放疗与同步推量调强放疗预后比较

目的 探讨同步推量调强放疗（SIB-IMRT）技术治疗中晚期宫颈癌患者的不良反应、远期疗效及相关预后因素。 方法 回顾性分析2009年1月至2015年6月收治的277例中晚期未手术的宫颈癌患者,其中70例行IMRT,207例行SIB-IMRT。比较中晚期宫颈癌患者行IMRT与SIB-IMRT后的不良反应,并进行远期疗效及预后因素分析。采用Kaplan-Meier法计算生存率,Cox法行多因素预后分析。 结果 IMRT组与SIB-IMRT组的随访率均为100%。与IMRT相比,SIB-IMRT未增加患者直肠及膀胱的急性毒性反应（χ2=0.306和0.971,P均>0.05）和远期毒性反应（χ2=0.014和0.381,P均>0.05）。IMRT组及SIB-IMRT组患者1年总生存率（OS）分别为100%和99.5%,3年OS分别为75.0%和84.7%,差异无统计学意义（χ2=0.339和0.674,P均>0.05）。患者年龄和治疗前淋巴结状态是所有入组患者（χ2=7.971和15.938,P均 < 0.05）及SIB-IMRT组患者（χ2=7.503和10.048,P均 < 0.05）生存的预后影响因素。 结论 初步结果表明SIB-IMRT技术安全可行,且可以减少后装治疗次数,减轻患者后装治疗的不适及痛苦。对于中晚期宫颈癌患者,SIB-IMRT是一种可尝试的外照射技术。     

采用风险分类分析局部中晚期鼻咽癌单纯调强放疗疗效

目的 探讨采用风险分类方法评估局部中晚期鼻咽癌单纯调强放疗疗效的可行性,为前瞻性研究提供依据。 方法 将185例接受单纯调强放疗的局部中晚期鼻咽癌病例,按治疗后死亡风险分为高危组和低危组(无高危因素),高危因素包括下列之一:GTVnx > 30 cm³;T₄N₂M₀期;颈部多个淋巴结转移,其中一个短径 > 4 cm,以及任何T和N₃M₀期。分析和比较两组病例的临床疗效。 结果 中位随访时间110.9个月(6.7~152.4个月)。高危组和低危组的5年总生存率、局部区域无复发生存率、无远处转移生存率分别为61.0%和90.5%(χ²=30.298,P<0.05)、78.3%和91.5%(χ²=6.352,P<0.05)、71.6% 和92.0%(χ²=16.346,P<0.05)。 结论 该风险分类方法简单易行,可以区分局部中晚期鼻咽癌中的不同失败风险病例,有利于指导临床有针对性开展前瞻性研究。     

鼻咽癌时间调节化疗诱导加同期调强放疗的疗效分析

目的 探讨顺铂+氟尿嘧啶(PF)方案时间调节化疗诱导加同期调强放疗(IMRT)治疗鼻咽癌的临床疗效。方法 回顾性分析48例初治鼻咽癌患者行PF方案时间调节化疗诱导联合同期放化疗的疗效。将鼻咽和颈部的靶体积划分为鼻咽大体肿瘤体积(GTV_nx)、颈部大体肿瘤体积(GTV_nd)、临床靶体积1(CTV₁)和临床靶体积2(CTV₂)。GTV_nx、GTV_nd、CTV₁、CTV₂处方剂量分别73.92~77.88、69.96、60.06~66.00、50.96~56.00 Gy,采用传统照射分割方式。采用Kaplan-Meier法进行生存分析。RTOG／EORTC标准评价急性反应和晚期损伤。结果 完全缓解(CR)20例,占41.6%,部分缓解(PR)23例,占47.9%,稳定(SD)2例,占4.2%。肿瘤局部控制率为89.6%,1、2、4年的生存率分别是93.8%、79.2%、64.5%。多数患者仅表现为1~2级急性反应和0~1级晚期损伤,未观察到4级急性反应和晚期损伤。剂量体积分布直方图(DVH)分析显示IMRT提高了靶体积照射总剂量和分次剂量,减少了危及器官受照总剂量和分次剂量。结论 PF方案时间调节化疗诱导加同期配合IMRT是鼻咽癌安全的治疗方案。     

快速旋转调强与固定射野动态调强在直肠癌术前放疗中的剂量学比较

目的 比较快速旋转调强(RapidArc)与固定射野动态调强(dIMRT)两种放射治疗技术在直肠癌术前放疗中的剂量学差异.方法 采用两种治疗技术对10例Ⅱ、Ⅲ期直肠癌术前患者设计同步加量治疗计划.处方剂量为GTV 50.6 Gy,分22次;PTV41.8 Gy,分22次,危及器官限量参考临床常规要求.在95%体积的PTV达到处方剂量前提下,比较两种计划的剂量体积直方(DVH)图、靶区和危及器官剂量、靶区剂量适形度、剂量分布均匀性、机器跳数以及治疗时间.结果 RapidArc计划中,GTV和PTV的靶区剂量适形度较高(t=7.643、8.226,P＜0.05);而靶区剂量均匀性略低于dIMRT(t=-10.065、-4.235,P＜0.05).RapidArc计划中大、小肠的平均受量显著低于dIMRT计划(t=2.781,P＜0.05).膀胱平均受照剂量略低于dIMRT,股骨头的平均受量略高于dIMRT,但差异无统计学意义.RapidArc计划机器跳数减少48.5%,平均治疗时间节省79.5%.结论 RapidArc与dIMRT计划在直肠癌术前放射治疗的剂量学上无明显差异.RapidArc每次治疗时间明显缩短,减少了治疗期间患者非主观运动引起的误差,总的机器跳数降低,减少了正常组织照射.

Abstract：

Objective To compare the dosimetric difference between RapidArc and fixed gantry angle dynamic intensity modulated radiotherapy (dIMRT) in developing the pre-operative radiotherapy for rectal cancer patients.Methods Two techniques,RapidArc and dIMRT,were used respectively to develop the synchronous intensity modulated plans for 10 stage Ⅱ and Ⅲ rectal cancer patients at the dose of gross tumor volume (GTV) of 50.6 Gy divided into 22 fractions and planning target volume (PTV) of 41.8 Gy divided into 22 fractions.Both plans satisfied the condition of 95% of PTV covered by 41.8 Gy.The dose-volume histogram data,isodose distribution,monitor units,and treatment time were compared.Results The two kinds of dose volume histogram (DVH) developed by these two techniques were almost the same.The conformal indexes of GTV and PTV by RapidArc were better than those by dIMRT (t =7.643,8.226 ,P < 0.05),while the homogeneity of target volume by dIMRT was better (t =-10.065,-4.235 ,P <0.05).The dose of rectum and small bowel planned by RapidArc was significantly lower than that by dIMRT (t =2.781 ,P <0.05).There were no significant differences in the mean doses of bladder and femoral head between these two techniques.The mean monitor units of RapidArc was 475.5,fewer by 48.5% in comparison with that by the dIMRT (924.6).The treatment mean time by RapidArc was 1.2min,shorter by 79.5% in comparison with that by dIMRT (5.58 min).Conclusions There is no significant dosimetric difference between the two plans of RapidArc and dIMRT.Compared with dIMRT,RapidArc achieves equal target coverage and organs at risk(OAR) sparing while using fewer monitor units and less time during radiotherapy for patient with rectal cancer.     

基于深度学习的直肠癌术后调强放疗剂量分布预测

目的 建立一种深度学习模型预测调强放疗（IMRT）的三维剂量分布。方法 收集直肠癌术后IMRT患者共110例,随机数表法选择其中90例作为训练验证集并作9折交叉验证,剩下20例作为测试集。构建3D U-Res-Net模型,以CT影像、靶区和危及器官（OARs）的解剖结构以及射束信息作为输入,IMRT剂量作为输出训练该模型,并用来预测测试集病例的剂量分布。采用三维剂量分布以及剂量—体积直方图（DVH）剂量参数评估预测精确性。结果 在三维剂量分布上,体素剂量的平均预测偏差为-2.12%~2.88%、平均绝对误差为2.55%~5.75%;等剂量面的Dice系数均在0.9以上,平均霍夫距离（HD₉₅）和平均表面距离（MSD）分别0.61~1.54 cm和0.21~0.45 cm。对于DVH剂量参数,除膀胱D_mean（P=0.048）以外,其他剂量学参数差异均无统计学意义（P>0.05）。结论 基于3D U-Res-Net模型可以实现直肠癌术后IMRT剂量分布预测,为自动计划设计奠定基础。     

铅门跟随技术与铅门固定技术在直肠癌术前调强放疗中的剂量学比较

目的 研究固定射野动态调强放疗铅门跟随技术与铅门固定技术在直肠癌术前调强放疗中的剂量学差异.方法 采用两种治疗技术对10例直肠癌术前患者设计治疗计划.在95%体积的计划靶区(PTV)和计划肿瘤区(PGTV)满足处方剂量的前提下,尽量降低危及器官的剂量.比较两组治疗计划的剂量-体积直方图,评估靶区及危及器官的剂量分布.分别将两组治疗计划用电离室矩阵2D-Array 729和OCTAVIUS(PTW)模体进行剂量验证.结果 两组计划的靶区均达到临床处方剂量的要求.PTV和PGTV的最大剂量与平均剂量差异无统计学意义.铅门跟随动态调强计划中全身的V₅、V₁₀、V₂₀、V₃₀、V₄₀、D_mean以及双侧股骨头、膀胱、小肠的V₁₀、V₂₀、V₃₀和D_mean均低于铅门固定动态调强计划的相应值,差异有统计学意义(t=-2.32~12.24,P<0.05);双侧股骨头、膀胱、小肠的V₄₀以及D_max差异无统计学意义.采用γ-2D分析两组计划的通过率,两组计划均通过剂量验证.结论 直肠癌术前放疗患者采用固定射野动态调强放疗铅门跟随技术与铅门固定技术两种技术,其靶区和危及器官受量均能满足临床治疗要求,而铅门跟随技术能够更好地降低正常组织和危及器官的低剂量照射.     

基于Pinnacle3自动化计划设计模块在直肠癌调强放疗的应用研究

目的 通过比较自动化计划设计（Auto-Planning,AP）和调强放疗（IMRT）在直肠癌调强计划设计中的靶区和危及器官的剂量学差异,探讨AP在直肠癌计划设计中的优势。方法 选取10例直肠癌术后放疗病例,用Pinnacle³9.10计划系统基于同一CT图像进行IMRT和AP计划设计,比较两种不同计划的剂量体积直方图,分析靶区适形度指数（CI）、均匀性指数（HI）和危及器官受照剂量的差异。结果 AP计划中,靶区D_mean和D_min略有增加,D_maxcGy略有减小,差异有统计学意义（t=-1.36、-3.03、0.37,P<0.05）。D₂、D₉₅、D₉₈差异均无统计学意义（P>0.05）。AP计划中靶区的HI值有所降低,CI值有所提高,差异有统计学意义（t=1.24、0.10,P<0.05）。危及器官中膀胱V₄₀、V₅₀,小肠的 V₃₀、V₄₅、V₅₀,左右股骨头V₃₀、V₄₀,在AP计划与IMRT计划比较中差异有统计学意义（t=-3.21~1.02,P<0.05）。膀胱V₃₀、V₄₅,小肠V₄₀及左右股骨头V₄₅受照剂量体积均略低于IMRT计划,但差异无统计学意义（P>0.05）。结论 直肠癌AP计划能够达到比IMRT计划更好的靶区适形度,能有效降低靶区最高剂量,增加靶区最低剂量,减少热点和冷点,同时降低危及器官受照剂量,更好的保护正常组织。     

直肠癌术后三种不同放疗计划的剂量学比较

目的 探讨直肠癌术后螺旋断层放疗(HT)、静态调强放疗(IMRT)及三维适形放疗(3D-CRT)的剂量学特点,为临床选择直肠癌术后放疗方法提供依据.方法 回顾性选取10例Ⅱ、Ⅲ期中低位直肠癌切除术(Dixon手术)后患者,在其CT定位图像上勾画靶区及危及器官,并进行HT、IMRT及3D-CRT计划设计.要求至少95％的PTV达到处方剂量为50 Gy.结果 3种治疗计划均能满足处方剂量要求;除3D-CRT计划外,HT计划与IMRT计划均能较好地满足各危及器官剂量限制要求.HT、IMRT、3D-CRT计划的适形度指数CI分别为0.86、0.82和0.62(F=206.81,P＜0.001),剂量均匀性指数(HI)分别为0.001、0.157和0.205(x2 =15.8,P＜0.001).3D-CRT计划骨盆V50、膀胱V40、小肠V50、股骨头D5明显高于IMRT与HT计划(P＜0.05),而后两者差别无统计学意义.HT计划小肠V15大于IMRT计划与3D-CRT计划(71.1％ vs.63.3％、67.7％),差异无统计学意义.结论 HT、IM RT及3D-CRT3种治疗计划均可满足直肠癌靶区处方剂量要求.HT计划适形度和均匀性最好,其次为IMRT计划,3D-CRT计划最差.HT计划满足所有危及器官的剂量限制,对正常组织的保护略优于IMRT计划.3D-CRT计划简便、实用性强,但对危及器官的保护较差.     

直肠癌新辅助同步加量调强放疗对侧方淋巴结转移的影响

目的 在侧方淋巴结转移的直肠癌中,评估侧方淋巴结加量放疗的疗效及安全性。方法 2016年1月至2022年12月入组103例合并侧方淋巴结转移的直肠癌患者,按随机数表法分为加量放疗组52例和常规放疗组51例。加量放疗组在盆腔放疗50 Gy的基础上,侧方淋巴结同步加量放疗至60 Gy。常规放疗仅盆腔放疗剂量50 Gy。研究首要终点为侧方复发率,比较两组的疗效及不良反应。结果 加量放疗组和常规放疗组新辅助放疗的不良反应及手术并发症相仿,侧方淋巴结治疗有效率分别为76.9%和56.9%(χ²=4.69,P=0.03),局部复发率分别为7.7%和25.5%(χ²= 5.92,P = 0.015),侧方复发率分别为3.8%和23.5%(χ²= 8.49,P = 0.004)。单因素分析显示,同步加量放疗、放疗后侧方淋巴结短径< 5 mm以及术后淋巴结病理阴性为侧方复发相关因素;多因素回归分析显示,加量放疗(HR=6.42, 95% CI: 1.40~29.49)及放疗后侧方淋巴结短径<5 mm(HR=0.17, 95%CI: 0.04~0.66)为侧方复发的独立相关因素。两组3年无病生存率(DFS)分别为73.25%和62.6%(P＞0.05),3年总生存率(OS)分别为87%和82.5%(P＞0.05)。结论 侧方淋巴结转移直肠癌同步加量放疗安全有效,加量放疗和新辅助治疗后侧方淋巴结短径<5 mm是侧方复发的独立影响因素。     

Optimal beam design on intensity-modulated radiation therapy with simultaneous integrated boost in nasopharyngeal cancer

This study aims to determine the optimal beam design among various combinations of field numbers and beam trajectories for intensity-modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB) technique for the treatment of nasopharyngeal cancer (NPC). We used 10 fields with gantry angles of 155°, 130°, 75°, 25°, 0° L, 0° R, 335°, 285°, 230°, and 205° denoted as F10. To decrease doses in the spinal cord, the F10 technique was designed by featuring 2 pairs of split-opposed beam fields at 155° to 335° and 205° to 25°, as well as one pair of manually split beam fields at 0°. The F10 technique was compared with 4 other common field arrangements: F7E, 7 fields with 50° equally spaced gantry angles; F7, the basis of F10 with 155°, 130°, 75°, 0°, 285°, 230°, and 205°; F9E, 9 fields with 40° equally spaced gantry angles; and FP, 7 posterior fields with 180°, 150°, 120°, 90°, 270°, 240°, and 210°. For each individual case of 10 patients, the customized constraints derived after optimization with the standard F10 technique were applied to 4 other field arrangements. The 4 new optimized plans of each individual case were normalized to achieve the same coverage of planning target volume (PTV)_63 Gy as that of the standard F10 technique. The F10 field arrangement exhibited the best coverage in PTV_70 Gy and the least mean dose in the trachea-esophagus region. Furthermore, the F10 field arrangement demonstrated the highest level of conformity in the low-dose region and the least monitor unit. The F10 field arrangement performed more outstandingly than the other field arrangements in PTV_70 Gy coverage and spared the central organ. This arrangement also exhibited the highest conformity and delivery efficiency. The F10 technique is recommended as the standard beam geometry for the SIB-IMRT of NPC.     

碳离子调强放射治疗复发性局部晚期鼻咽癌的近期疗效及不良反应

目的 分析局部复发性鼻咽癌患者再程调强碳离子放射治疗（IMCT）和调强X射线放射治疗（IMXT）后的近期疗效及不良反应。方法 收集本院2015年5月至9月收治的14例确诊为局部复发性鼻咽癌的患者,经再程IMCT治疗后,观察其治疗相关不良反应及近期疗效,并与2012年5月至2014年5月接受再程IMXT挽救性治疗的47例患者进行比较分析。复发肿瘤体积的IMCT和IMXT的处方剂量分别为50～60 GyE（2.0～2.5 GyE/次）和54～66 Gy/27～33次（2.0～2.1 Gy/次）。结果 两组患者在性别、年龄、初诊分期、初诊治疗策略、复发距首次IMXT时间间隔、复发T、N分期差异均无统计学意义（P>0.05）。两组患者放疗后3个月的完全缓解率（64.3%和78.7%）差异无统计学意义（P>0.05）,且在6个月内均无局部肿瘤进展,但IMXT组有2例死亡,其中1例死于鼻咽坏死大出血。IMCT组治疗中的急性中重度黏膜炎的发生率为0,明显低于IMXT组的31.9%（P<0.05）。IMXT治疗后6个月内黏膜坏死的发生率为29.8%,明显高于IMCT组的0（P<0.05）;IMXT组有2例（4.3%）伴症状的颞叶坏死,IMCT组无颞叶坏死;两组均无颅神经损伤发生。结论 同再程IMXT挽救治疗相比,复发性局部晚期鼻咽癌再程IMCT后近期疗效类似,且未出现2级或以上的近期不良反应,但IMCT的远期疗效尚需更长时间的观察。     

Simultaneous integrated boost intensity-modulated radiotherapy for treatment of locally advanced non-small-cell lung cancer: a retrospective clinical study

Objective:

To evaluate the clinical efficacy and safety of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for patients with locally advanced non-small-cell lung cancer (LANSCLC).

Methods:

48 patients with LANSCLC treated with SIB-IMRT from January 2010 to April 2012 were retrospectively analysed. A radiation dose of 45–63 Gy (median dose, 51.58 Gy) was delivered to the planning target volume (1.8–2.0 Gy daily fractions) simultaneously with 55.0–74.2 Gy (median dose, 63 Gy) to the planning gross tumour volume (2.00–2.25 Gy daily fractions). 45 patients received concurrent/sequential chemotherapy. The overall survival (OS), locoregional recurrence-free survival (LRFS) and progression-free survival (PFS) were estimated using the Kaplan–Meier method. Treatment-related pneumonitis and oesophagitis were graded according to the Common Terminology Criteria for Adverse Events v. 4.0.

Results:

By 1 July 2013, 29 of the 48 patients were dead. The median follow-up time for the survivors was 28 months (19–44 months). The median OS and PFS were 21 and 14 months, respectively. The median LRFS time was not reached. The 2-year LRFS, OS and PFS were 62.5%, 45.1% and 28.0%, respectively. Two patients experienced Grade 3 treatment-related pneumonitis, two patients experienced Grade 5 treatment-related pneumonitis and two patients had ≥Grade 3 oesophagitis.

Conclusion:

SIB-IMRT appears to be an effective therapeutic option in patients with LANSCLC and warrants further evaluation with increased number of patients in prospective clinical trials.

Advances in knowledge:

This study explores the feasibility of delivering tumoricidal doses of radiation to primary lesions in non-small-cell lung cancer.The true value of radiotherapy confined to the thorax is indisputable in the treatment of locally advanced non-small-cell lung cancer (LANSCLC). However, even with standard chemoradiation, it is difficult to achieve durable local control, and this contributes to the high morbidity and mortality of patients with non-small-cell lung cancer (NSCLC).¹ Despite a demonstrated positive association between the radiation dose and tumour control,² results of the Radiation Therapy Oncology Group (RTOG) 0617 clinical (Phase III) trial showed that the overall survival (OS) of Stage III NSCLC patients given high-dose (74 Gy) conformal radiation therapy with concurrent chemotherapy was no better than that of patients given the standard dose (60 Gy).³The unpublished data showed that the higher dose had no further effects on improving the OS during the RTOG 0617 trial, and the reason still remained unclear, the radiation-induced decline in quality of life may be responsible for this.⁴ Thus, researchers turned their attention to focus on better ways of delivering radiation to tumours, while sparing surrounding normal structures. Initially, the radiation dose applied to the gross tumour was identical to that directed at targeted nodal areas, but logic suggests that the dose required to control subclinical lesions should be lower than that of the primary disease.Simultaneous integrated boost (SIB) is a recent modality applied in conjunction with intensity-modulated radiotherapy (IMRT) in the treatment of malignancies.^5,6 Simultaneous integrated boost–intensity-modulated radiotherapy (SIB-IMRT) simultaneously delivers a higher dose to the primary disease and a relatively lower dose to the subclinical disease or selected other regions. However, outcomes for SIB-IMRT in LANSCLC remain to be determined.Herein, we retrospectively analysed clinical outcomes of patients with LANSCLC treated with SIB-IMRT to evaluate the feasibility of this technology and to provide evidence in support of future clinical study.