Background Helical tomotherapy （HT） is a new image-guided intensity-modulated radiation therapy （IMRT）.The aim of this study was to evaluate the changes in the target volume and organs at risk （OARs） of patients...Background Helical tomotherapy （HT） is a new image-guided intensity-modulated radiation therapy （IMRT）.The aim of this study was to evaluate the changes in the target volume and organs at risk （OARs） of patients with nasopharyngeal carcinoma （NPC） during helical tomotherapy.Methods Forty-three patients with NPC and treated via HT from March 2008 to January 2010 were reviewed retrospectively.Repeated CT scanning and plan adaptation were conducted at the 20th fraction during radiotherapy.The volumetric differences between the two scans were evaluated for nasopharyngeal tumor and retro- pharyngeal lymph nodes （GTVnx）,neck lymph nodes （GTVnd）,and parotid glands,as well as the axial diameter of the head.Results The median interval between the two scans was 25 days （23-28 days）.The volumetric decrease in GTVnx was 30.1% （median,29.8%） and in GTVnd 41.6% （median,45.9%）.The variation in the GTVnd volume was correlated with the weight loss of the patient.The volume of the left parotid gland decreased by 35.5% （median,33.4%） and of the right parotid glands decreased by 36.8% （median,33.5%）.The axial diameter of the head decreased by 9.39% （median,9.1%）.Conclusions The target volume and OARs of patients with NPC varied considerably during HT.These changes may have potential dosimetric effects on the target volume and/or OARs and influence the clinical outcome.Repeated CT scanning and replanning during the HT for NPC patients with a large target volume or an obvious weight loss are recommended.展开更多
目的:比较宫颈癌盆腔照射螺旋断层放射治疗(Helical Tomotherapy,HT)计划与七野-静态调强放疗(7F-IMRT)计划的靶区和危及器官的剂量学差异。方法:选取2015年3月～2017年10月行HT治疗的25例宫颈癌患者,均采用俯卧位,憋尿状态。分别进行HT...目的:比较宫颈癌盆腔照射螺旋断层放射治疗(Helical Tomotherapy,HT)计划与七野-静态调强放疗(7F-IMRT)计划的靶区和危及器官的剂量学差异。方法:选取2015年3月～2017年10月行HT治疗的25例宫颈癌患者,均采用俯卧位,憋尿状态。分别进行HT和7F-IMRT两种计划设计,比较两种计划模式之间靶区和危及器官之间的剂量学参数及机器输出跳数。结果:(1)计划靶区(PTV):HT组CI和HI均优于7F-IMRT组,具有统计学差异(0.898±0.017 vs 0.834±0.013,P<0.001;0.062±0.012 vs 0.109±0.019,P<0.001);HT组PTV的D_1、D_2均低于7F-IMRT组(P<0.001),D_(mean)、D_(98)、D_(95)均较7F-IMRT组高(P=0.048,P<0.001,P=0.015)。(2)对于正常组织,HT组小肠、结肠、直肠和膀胱的D_(max)、D_(mean)、V_(30)、V_(40)以及直肠V_(50)均显著低于7F-IMRT组(P<0.001,P<0.001,P<0.001,P=0.001,P=0.006),其余V_(50)略低,无统计学差异(P=0.130);HT组双侧股骨头V_(25)、D_5、D_(mean)、D_(max)也显著低于7F-IMRT组(P<0.001);但是,HT组的机器输出量明显高于7F-IMRT组。结论:HT计划在适形度、均匀性及周围正常组织保护上显著优于7F-IMRT计划,在充分保证靶区剂量的同时又不增加患者放疗毒副反应;但其机器输出量高于7F-IMRT计划,对射束的利用率不高。在后续治疗实施过程中,HT系统作为影像引导放射治疗技术,确保每次治疗过程中的精准度,值得临床应用。展开更多
目的观察宫颈癌术后螺旋断层放疗与常规调强放疗的急性放疗反应和高危器官剂量学方面的差异。方法 126例宫颈癌术后放疗患者,螺旋断层放疗(Helical Tomotherapy,HT)68例、调强放疗(Intensity-Modulated Radiotherapy,IMRT)58例;全盆腔放...目的观察宫颈癌术后螺旋断层放疗与常规调强放疗的急性放疗反应和高危器官剂量学方面的差异。方法 126例宫颈癌术后放疗患者,螺旋断层放疗(Helical Tomotherapy,HT)68例、调强放疗(Intensity-Modulated Radiotherapy,IMRT)58例;全盆腔放疗46-50.4Gy/23-28次,高危淋巴引流区照射60Gy/28次。采用RTOG(Radiation Therapy Oncology Group)和EORTC(European Organization for Research on Treatment of Cancer)评分标准评价血常规、直肠和膀胱的急性放射反应;根据剂量体积直方图(Dose Volume Histogram,DVH)评价两种治疗计划的靶区适形度、剂量均匀指数及直肠、膀胱照射剂量体积对比。结果放疗期间HT和IMRT两组1级急性反应发生率在直肠为27.94%和46.55%(χ2=4.68,P<0.05);膀胱为17.65%和24.13%(χ2=1.93,P>0.05);两组均无≥2级急性放疗反应发生。HT和IMRT组靶区适形指数和剂量均匀指数分别为0.73+0.082,1.047+0.026和0.686+0.072,1.13+0.017。结论宫颈癌术后盆腔放疗在剂量学方面和对正常组织的保护作用HT组比IMRT组具有明显优势。展开更多
文摘Background Helical tomotherapy （HT） is a new image-guided intensity-modulated radiation therapy （IMRT）.The aim of this study was to evaluate the changes in the target volume and organs at risk （OARs） of patients with nasopharyngeal carcinoma （NPC） during helical tomotherapy.Methods Forty-three patients with NPC and treated via HT from March 2008 to January 2010 were reviewed retrospectively.Repeated CT scanning and plan adaptation were conducted at the 20th fraction during radiotherapy.The volumetric differences between the two scans were evaluated for nasopharyngeal tumor and retro- pharyngeal lymph nodes （GTVnx）,neck lymph nodes （GTVnd）,and parotid glands,as well as the axial diameter of the head.Results The median interval between the two scans was 25 days （23-28 days）.The volumetric decrease in GTVnx was 30.1% （median,29.8%） and in GTVnd 41.6% （median,45.9%）.The variation in the GTVnd volume was correlated with the weight loss of the patient.The volume of the left parotid gland decreased by 35.5% （median,33.4%） and of the right parotid glands decreased by 36.8% （median,33.5%）.The axial diameter of the head decreased by 9.39% （median,9.1%）.Conclusions The target volume and OARs of patients with NPC varied considerably during HT.These changes may have potential dosimetric effects on the target volume and/or OARs and influence the clinical outcome.Repeated CT scanning and replanning during the HT for NPC patients with a large target volume or an obvious weight loss are recommended.
文摘目的:比较宫颈癌盆腔照射螺旋断层放射治疗(Helical Tomotherapy,HT)计划与七野-静态调强放疗(7F-IMRT)计划的靶区和危及器官的剂量学差异。方法:选取2015年3月～2017年10月行HT治疗的25例宫颈癌患者,均采用俯卧位,憋尿状态。分别进行HT和7F-IMRT两种计划设计,比较两种计划模式之间靶区和危及器官之间的剂量学参数及机器输出跳数。结果:(1)计划靶区(PTV):HT组CI和HI均优于7F-IMRT组,具有统计学差异(0.898±0.017 vs 0.834±0.013,P<0.001;0.062±0.012 vs 0.109±0.019,P<0.001);HT组PTV的D_1、D_2均低于7F-IMRT组(P<0.001),D_(mean)、D_(98)、D_(95)均较7F-IMRT组高(P=0.048,P<0.001,P=0.015)。(2)对于正常组织,HT组小肠、结肠、直肠和膀胱的D_(max)、D_(mean)、V_(30)、V_(40)以及直肠V_(50)均显著低于7F-IMRT组(P<0.001,P<0.001,P<0.001,P=0.001,P=0.006),其余V_(50)略低,无统计学差异(P=0.130);HT组双侧股骨头V_(25)、D_5、D_(mean)、D_(max)也显著低于7F-IMRT组(P<0.001);但是,HT组的机器输出量明显高于7F-IMRT组。结论:HT计划在适形度、均匀性及周围正常组织保护上显著优于7F-IMRT计划,在充分保证靶区剂量的同时又不增加患者放疗毒副反应;但其机器输出量高于7F-IMRT计划,对射束的利用率不高。在后续治疗实施过程中,HT系统作为影像引导放射治疗技术,确保每次治疗过程中的精准度,值得临床应用。
文摘目的观察宫颈癌术后螺旋断层放疗与常规调强放疗的急性放疗反应和高危器官剂量学方面的差异。方法 126例宫颈癌术后放疗患者,螺旋断层放疗(Helical Tomotherapy,HT)68例、调强放疗(Intensity-Modulated Radiotherapy,IMRT)58例;全盆腔放疗46-50.4Gy/23-28次,高危淋巴引流区照射60Gy/28次。采用RTOG(Radiation Therapy Oncology Group)和EORTC(European Organization for Research on Treatment of Cancer)评分标准评价血常规、直肠和膀胱的急性放射反应;根据剂量体积直方图(Dose Volume Histogram,DVH)评价两种治疗计划的靶区适形度、剂量均匀指数及直肠、膀胱照射剂量体积对比。结果放疗期间HT和IMRT两组1级急性反应发生率在直肠为27.94%和46.55%(χ2=4.68,P<0.05);膀胱为17.65%和24.13%(χ2=1.93,P>0.05);两组均无≥2级急性放疗反应发生。HT和IMRT组靶区适形指数和剂量均匀指数分别为0.73+0.082,1.047+0.026和0.686+0.072,1.13+0.017。结论宫颈癌术后盆腔放疗在剂量学方面和对正常组织的保护作用HT组比IMRT组具有明显优势。
