121例鼻咽癌螺旋断层治疗结果分析

目的 回顾分析本院螺旋断层治疗(HT)的鼻咽癌患者的短期疗效和不良反应。方法 2007—2010年间收治 121例初治鼻咽癌患者,其中单纯HT 31例,HT同期化疗或靶向治疗 90例。原发灶及转移性淋巴结计划靶区 70~74 Gy分33次,高危计划靶区 60.0~62.7 Gy分33次,低危计划靶区 52~56 Gy分33次。根据美国放疗肿瘤组织或欧洲癌症研究与治疗组织标准评价急性不良反应。     

螺旋断层治疗剂量验证γ通过率影响因素研究

目的 研究在螺旋断层治疗(HT)计划验证中对验证γ通过率的影响因素。方法 人为引入误差后测量在有误差情况下ArcCheck的γ通过率。引入误差包括三维方向ArcCheck摆位错误、机架起始角度错误、模体中剂量计算对应错误的密度—CT值曲线、剂量率偏移标定剂量率。测量结果与未引入误差结果相对比,分别采用2%/2 mm、3%/3 mm标准对结果进行分析。对不同扫描CT获取的ArcCheck模体图像对验证通过率的影响进行分析。配对t检验差异。结果 人为引入误差后3%/3 mm标准下左右、上下、前后方向γ通过率分别下降2.7%、7.2%、3.6%(P=0.002、0.022、0.007),2%2 mm时下降更明显分别为4.6%、15.7%、7.6%(P=0.001、0.003、0.002)。使用KVCT、MVCT对ArcCheck模体扫描图像进行验证后3%/3 mm和2%/2 mm标准下γ通过率均相近(98.6%∶98.7%,P=0.859和92.7%∶92.8%,P=0.984)。结论 摆位精度和设备参数的正确与否对HT剂量分布的影响很大,应加强机器的质量控制精度。MVCT和KVCT扫描获取模体的图像均可用于验证计算。     

应用Delta4三维探测器阵列进行螺旋断层治疗计划剂量验证

目的 研究采用Delta4三维半导体探测器阵列对螺旋断层治疗(HT)计划实施剂量验证的可行性。方法 采用ScandiDos公司Delta4三维半导体探测器阵列验证10例恶性肿瘤患者HT计划。通过该系统兆伏特CT成像和配准来确保实现Delta4探测器阵列的精确摆位。实施质量保证的治疗计划照射后,将Delta4探测器阵列测量获得的平面剂量分布与计划系统模体计划计算获得的进行比较。选择阈值水平分别为5%、10%、20%、70%、90%时3%/2 mm、3%/3 mm、3%/4 mm、3%/5 mm标准分别进行γ通过率验证。结果 测量所得剂量分布与计算结果在相应平面几何分布均呈良好一致性。γ平均通过率均>94.89%。结论 Delta4三维探测器阵列用于HT计划验证能获满意结果,一般情况下可有效替代传统胶片验证。     

螺旋断层治疗计划系统升级前后验证结果及叶片打开时间对比研究

目的 比较4.0.4、4.2.3版本螺旋断层治疗计划系统叶片打开时间参数和γ通过率差别及改进状况。方法 用4.0.4、4.2.3版本治疗计划系统各选择 345例计划进行回顾性比较。从患者备份计划文件提取出Sinogram并计算叶片打开时间参数进行评估分析,包含最大叶片打开时间、叶片平均打开时间、打开时间<100 ms的叶片数比例、打开时间在最大时间5ms范围内叶片数比例及出束总时间。对升级前后计划的γ通过率(分析标准为3mm/3%、10%Threshold和全局误差)及叶片打开时间参数对比采用独立t检验分析,采用多元线性回归评估叶片打开时间参数与γ通过率之间相关性。结果 4.0.4版本的γ通过率低于4.2.3版本(97.86%∶98.6%,P<0.001),4.2.3版本的最大时间与投影时间的间隔低于4.0.4版本(1 ms∶11ms,P<0.001)。多元线性回归显示4.0.4版本最大打开时间附近5ms范围内的叶片数比例和出束总时间与γ通过率呈显著负相关(P<0.001),而4.2.3版本仅出束总时间与γ通过率呈显著负相关(P<0.001)。结论 螺旋断层治疗系统升级到4.2.3版本后提高了计划验证的γ通过率,且有效修复了旧版系统在最大叶片打开时间附近的叶片可能会导致γ通过率下降的问题。     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

目的 研究采用二维电离室阵列对螺旋断层治疗(HT)的调强计划实施剂量验证的可行性,寻求建立一套临床上针对该条件下患者治疗更为有效的剂量验证方法 .方法 采用IBA公司I'mRT MatriXX二维电离室阵列及其相配套MULTICube等效同体水模体对10例患者HT的调强计划实施验证.分别对二维电离室阵列实行冠状及纵向位测量,并获取模体中阵列轴平面和纵断面剂量分布.通过HT系统兆伏级CT图像实现模体精确配准及校正,以确保二维电离室阵列摆位准确性.束流照射后将二维阵列剂量测量平面分布与HT计划系统模体计划中计算平面结果 进行比较,定性或定量分析其绝对剂最及相对剂量验证情况.探讨其不同位置摆放来实现其测量方法 的可行性.结果 定性或定量分析所测量与计算绝对剂量点及相对剂量分布的结果 均显示出了较好一致性,点绝对测量与计算剂量偏差保持在±3%以内.MatrXX阵列测量的相对剂量分布与治疗计划系统模体中计算平面相比较,采用了Gamma法(3 mm或3%)进行2 mm栅格精度分析,γ≤1像素点平均通过率分别为97.76%、96.83%.结论 MatriXX二维电离室阵列可较好地进行绝对剂量及相对剂量测量,能较好地实现调强计划的剂量验证.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

用二维电离室阵列对螺旋断层治疗的调强计划进行剂量验证

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.     

食管癌患者螺旋断层治疗的摆位误差分析

目的 利用TOMO自带的MVCT图像引导系统,分析食管癌患者治疗摆位误差,指导计算CTV到PTV外扩间距。方法 随机抽取2016年间64例在我院接受TOMO治疗的食管癌患者,在每次摆位后行MVCT获得图像,并将其与定位时KVCT图像进行配准。记录患者在x、y、z轴平移和横截位旋转(roll)摆位误差并行t检验或单因素方差分析。利用M= 2.5∑+0.7δ计算PTV的外扩间距。结果 颈段、胸上段、胸中段、胸下段的CTV-PTV外扩间距在x、y、z轴向略有不同;胸上段食管癌患者使用头颈肩膜固定在y轴向平均摆位误差低于体膜固定(P=0.000);体膜固定时第5、6周z轴摆位误差略小于前几周(P=0.036);3种图像配准模式得出的摆位误差相近(x轴P=0.868,y轴P=0.491,z轴P=0.169,roll方向P=0.985)。结论 食管癌患者摆位误差较大,TOMO自带的图像引导系统MVCT可以很大程度减少摆位误差,确保每次治疗精度。同时建议临床上在不同食管癌分段使用不同CTV-PTV外扩间距。胸上段食管癌患者建议使用头颈肩膜来固定。     

旋转照射剂量测量仪（ArcCHECK）在螺旋断层放疗计划剂量验证中的应用

目的：研究旋转照射剂量测量仪（AreCHECK）在螺旋断层放疗（HT）计划剂量验证中的应用,寻求一种用于临床上的剂量验证方法。方法：采用AreCHECK对36例患者螺旋断层放疗（HT）计划进行剂量验证,用SNCPatients软件进行剂量分布1值分析,评估计划的剂量验证结果及实施的可行性。结果：36例患者HT计划剂量验证结果表明,采用Gamma法（3mm／3％）分析,叮≤1像素点平均通过率为99．7％±0．6％,γ通过率都大于95％。结论：ArcCHECK作为螺旋断层放疗计划的剂量验证稳定,可用于HT计划剂量分布验证。     

螺旋断层放疗MVCT成像剂量测量及其分析

背景与目的：螺旋断层放疗中治疗前／后通常采用MVCT（megavoltage coreputed tomography,MVCT）来实行图像引导下精确定位,成像过程中势必会增加患者的辐射剂量。通过体部及头部标准模体分别模拟患者MVCT成像条件来实现其剂量学测量及研究。方法：采用螺旋断层治疗机MVCT分别对圆柱形体部模体和自制标准头模体在不同螺距比（1．0、2．0、3．0）、扫描长度（4．8、7．2、9．6、12、14．4cm）及摆位条件下进行扫描,测量模体内各点扫描平均剂量变化,并对其剂量均匀性情况进行定性分析。结果：体部模体内MVCT扫描辐射剂量在0．599～2．876cGy之间：而头部模体点平均剂量为0．913～3．231cGy。测量结果表明,模体内所受照射剂量与螺距比值、扫描长度呈密切相关性;且MVCT扫描剂量与CT螺距值基本成反比关系。不同摆位条件下辐射剂量值沿模体径向大小而相应产生出其变化趋势。结论：实验结果有助于为治疗计划设计及图像引导治疗扫描范围提供较为现实而可靠的临床依据,减小患者治疗期间可能诱发肿瘤所获取的额外剂量。     

螺旋断层放疗系统调强放疗验证

目的 通过螺旋断层放疗系统一系列调强放疗验证方法的研究,探讨其调强放疗的质量保证验证方法是否可行.方法 采用断层放疗计划系统进行调强放疗计划设计.为实现其剂量验证,笔者采用圆柱形固体水模体、0.056cm3 AISL电离室及EDR2胶片来实现对计划进行绝对剂量及相对剂量验证.将剂最胶片和电离室分别置于模体中,调用患者治疗计划束流数据对模体进行模拟照射;由此得出轴向截面上的等剂量分布和点绝对剂量,与计划模体的等剂量曲线及计算剂量结果进行比对.束流照射前,利用调强放疗兆伏特CT对摆位模体实行图像引导,与计划系统中模体千伏特CT图像进行配准比较,实现验证模体摆位准确性.结果 轴向测得注量分布与断层放疗计划系统计算结果相一致,测量点绝对剂量测量的结果与计划系统的计算误差均在±3%以内.测量模体的摆位误差基本可保持在1mm以内,但由于床从摆位虚拟中心到束流中心之间存在垂直下降2mm的系统误差,需要在模体或患者摆位中予以考虑.结论 3个月临床实践证明断层放疗的调强放疗所采用上述质量保证措施是切实可行的,建立了其质最保证体系.     

胰腺癌螺旋断层调强放疗高剂量少分次模式的胃肠毒副反应相关因素分析

目的 探讨采用螺旋断层调强放疗治疗胰腺癌的胃肠毒副反应与剂量学的相关性。方法 将2014年1月—2015年1月接受螺旋断层调强放射治疗放疗的68例胰腺癌患者的资料进行分析。分析临床因素、胃及十二指肠剂量体积与放射性毒副反应分级的关系。结果 中位随访时间为9个月(4~16个月)。发生2级急性毒性反应18例,3级1例;发生2级晚期毒性反应17例,3级1例。单因素分析中,十二指肠的体积、Dmean、D1、D3、D5、D10、V5、V10、V15、V20、V25、V30、V35、V40、V5′、V10′、V15′、V20′、V25′、V30′、V35′、V40′、V45′与≥2级毒性反应的发生有相关性(P＜0.05)。Logistic多因素回归分析显示,十二指肠V45′是≥2级放射性胃肠毒性反应的独立影响因素(P＜0.05)。V45′的ROC分界值为0.5cm³。结论 十二指肠V45′是高剂量少分次放疗胃肠毒副反应发生的重要影响因素。