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目的 比较容积旋转调强放疗(VMAT)和常规调强放疗(IMRT)两种技术在乳腺癌保乳术后同步推量放疗中剂量学差异。方法 随机选择10例左侧乳腺癌保乳术后患者,使用MONACO 5.1计划系统,分别设计VMAT和IMRT计划,处方剂量均为PTV50Gy/25 f、PGTVtb60 Gy/25 f,评估两种计划靶区剂量适形指数(CI)、均匀性指数(HI),以及正常器官受照剂量(Gy)、机器跳数(MU)及治疗时间。结果 VMAT计划中靶区剂量的适形度明显优于IMRT(P<0.05),而患侧肺V5、V10、V20及健侧肺V5稍高于IMRT组(P<0.05)。结论 对于乳腺癌保乳术后同步推量放疗,VMAT和IMRT计划都可以满足临床剂量学的要求,VMAT在适形度方面对于IMRT计划有优势,并缩短了治疗时间。 相似文献
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目的 比较容积弧形调强(VMAT)、固定野动态调强(IMRT)及三维适形放疗(3D-CRT)技术对乳腺癌保乳术后采用部分乳腺放疗的剂量学差异。方法 选取20例临床分期为T1-2N0M0的早期乳腺癌保乳术后患者进行VMAT,并同时设计IMRT及3D-CRT,比较3种计划的剂量学参数,包括剂量-体积直方图(DVH)、靶区剂量适形度、靶区及危及器官的剂量、机器跳数及治疗时间。结果 IMRT及VMAT计划靶区剂量分布优于3D-CRT计划,其中最大剂量,平均剂量及适形指数(CI)组间比较差异具有统计学意义(F=14.86、8.57、18.23,P<0.05)。正常组织受量:VMAT计划在患侧乳腺V5上优于IMRT及3D-CRT计划(F=5.83,P<0.05);IMRT在患侧肺V20、V5及D5上有优势(F=16.39、3.62、4.81,P<0.05);在对侧肺的统计中,IMRT计划在最大剂量及D5上可以得到比VMAT和3D-CRT更低的剂量(F=3.99、3.43,P<0.05);VMAT、3D-CRT和IMRT计划所需机器跳数值分别为621.0±111.9、707.3±130.9、1161.4±315.6,计划间的差异有统计学意义(F=31.30,P<0.05)。VMAT、3D-CRT和IMRT计划所需治疗时间分别为(1.5±0.2)、(7.0±1.6)、(11.5±1.9)min。结论 IMRT和VMAT计划靶区剂量分布优于3D-CRT计划,而不提高患侧肺剂量。对于部分乳腺癌的放疗,容积弧形调强放疗在降低机器跳数和减少治疗时间方面具有明显优势。 相似文献
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目的 分析2 010例调强放疗计划剂量验证结果,为改进和完善调强放疗计划验证方法提供参考。方法 回顾性分析北京大学第三医院2012年2月—2016年2月美国瓦里安公司Trilogy加速器治疗的2 010例计划的剂量验证结果,其中调强放射治疗(IMRT)计划965例,容积旋转调强放疗(VMAT)计划1 045例。计划设计使用Eclipse计划系统,剂量验证采用MatriXX及Multicube模体。分析计划和测量等中心点剂量差异,3%/3 mm标准平面剂量分布的γ通过率。等中心点剂量差异<±3%定为通过,平面剂量分布γ通过率>90%定为通过。分析病变部位、治疗技术(IMRT和VMAT)对计划验证通过率的影响。结果 2 010例计划等中心点剂量平均差异为-0.3%±2.4%,γ通过率为97.9%±3.4%。88.2%和96.7%的计划能够通过点剂量验证和平面剂量验证标准。不同病变部位计划验证γ通过率不同(F=3.09,P<0.05)。不同病变计划点剂量和面剂量验证通过率不同(χ2=40.93、39.15,P<0.05)。IMRT和VMAT计划验证点剂量通过率和面剂量验证通过率差异均无统计学意义(P>0.05)。结论 大部分调强放疗计划能够通过计划验证,不同病变部位计划验证通过率不同,IMRT和VMAT计划验证通过率无差异。 相似文献
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目的 比较胸中下段食管癌3种放疗技术心脏和肺的剂量分布。方法 搜集2015年1月至2016年2月在浙江省肿瘤医院接受治疗的15例胸中下段食管鳞癌患者资料。患者均接受胸部放射治疗,每位患者共制作3套放疗计划。调强放疗(IMRT)和容积旋转调强放疗(VMAT)在RayStation 4.0v系统制作,螺旋断层放疗(TOMO)在TomoHTM Version 2.0.5系统制作。处方剂量60 Gy/30次。比较计划体积(PTV)、心脏、心脏亚单位以及肺剂量参数。结果 PTV、心脏和肺的平均体积为(399±355)、(671±274)和(3 907±1 717) cm3。与IMRT和VMAT相比,TOMO可以降低PTV、心脏、左心房及肺的最大剂量(H=10.889、7.433、12.080、11.401,P<0.05)。3种放疗技术的适形指数和均匀性指数差异无统计学意义(P>0.05)。结论 相较于IMRT和VMAT,TOMO可以降低PTV、心脏、左心房和肺的最大剂量,但均匀性及适形性差异无统计学意义。放疗过程中心脏与肺存在相互影响,TOMO技术可能带来的临床优势尚待进一步研究证实。 相似文献
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目的:探讨中央型肺癌调强适形放射治疗(IMRT)同一射野角度、不同优化方式对靶区和危及器官剂量分布的影响。方法:回顾性分析2017年11月至2019年10月在广州市番禺区中心医院接受IMRT的6例中央型肺癌患者的临床资料,其中男性5例、女性1例,中位年龄64 (53~73)岁。6例患者分别制定2种治疗计划:F-plan... 相似文献
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Raj N. Selvaraj M.S. D.A.B.R. D.A.B.M.P. Sushil Beriwal M.D. Roya J. Pourarian R.T.T. B.S.R.T. Ron J. Lalonde Ph.D. Alex Chen M.D. Kiran Mehta M.D. Gwendolyn Brunner M.S. Kathy A. Wagner C.M.D. Ning J. Yue Ph.D. Saiful M. Huq Ph.D. Dwight E. Heron M.D. 《Medical Dosimetry》2007,32(4):299-304
The purpose of this study was to evaluate the clinical implementation of tangential field IMRT using sliding window technique and to compare dosimetric parameters with 3-dimensional conformal radiation therapy (3DCRT). Twenty breast cancer patients were randomly selected for comparison of intensity modulated radiation therapy (IMRT)-based treatment plan with 3DCRT. Inverse treatment was performed using the sliding window technique, employing the Eclipse® Planning System (version 7.1.59, Varian, Palo Alto, CA). The dosimetric parameters compared were V95 (the percentage of target volume getting ≥95% of prescribed dose), V105, V110, and dose homogeneity index, DHI (percentage of target volume getting between 95% and 110% of prescribed dose). The mean V95, DHI, V105, and V110 for target volume for IMRT vs. 3D were 90.6% (standard deviation [SD]: 3.2) vs. 91% (SD: 3.0), 87.7 (SD: 6.0) vs. 82.6 (SD: 7.8), 27.3% (SD: 20.3) vs. 49.4% (SD: 14.3), and 2.8 (SD: 5.6) vs. 8.4% (SD: 7.4), respectively. DHI was increased by 6.3% with IMRT compared to 3DCRT (p < 0.05). The reductions of V105 and V110 for the IMRT compared to 3DCRT were 44.7% and 66.3%, respectively (p < 0.01). The mean dose and V30 for heart with IMRT were 2.3 (SD: 1.1) and 1.05 (SD: 1.5) respectively, which was a reduction by 6.8% and 7.9%, respectively, in comparison with 3D. Similarly, the mean dose and V20 for the ipsilateral lung and the percentage of volume of contralateral volume lung receiving > 5% of prescribed dose with IMRT were reduced by 9.9%, 2.2%, and 35%, respectively. The mean of total monitor units used for IMRT and 3DCRT was about the same (397 vs. 387). The tangential field IMRT for intact breast using sliding window technique was successfully implemented in the clinic. We have now treated more than 1000 breast cancer patients with this technique. The dosimetric data suggest improved dose homogeneity in the breast and reduction in the dose to lung and heart for IMRT treatments, which may be of clinical value in potentially contributing to improved cosmetic results and reduced late treatment-related toxicity. 相似文献
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《Medical Dosimetry》2014,39(3):227-234
The 3-dimensional conformal radiotherapy (3DCRT) technique is the standard for breast cancer radiotherapy. During treatment planning, not only the coverage of the planning target volume (PTV) but also the minimization of the dose to critical structures, such as the lung, heart, and contralateral breast tissue, need to be considered. Because of the complexity and variations of patient anatomy, more advanced radiotherapy techniques are sometimes desired to better meet the planning goals. In this study, we evaluated external-beam radiation treatment techniques for left breast cancer using various delivery platforms: fixed-field including TomoDirect (TD), static intensity-modulated radiotherapy (sIMRT), and rotational radiotherapy including Elekta volumetric-modulated arc therapy (VMAT) and tomotherapy helical (TH). A total of 10 patients with left-sided breast cancer who did or did not have positive lymph nodes and were previously treated with 3DCRT/sIMRT to the entire breast were selected, their treatment was planned with Monaco VMAT, TD, and TH. Dosimetric parameters including PTV coverage, organ-at-risk (OAR) sparing, dose-volume histograms, and target minimum/maximum/mean doses were evaluated. It is found that for plans providing comparable PTV coverage, the Elekta VMAT plans were generally more inhomogeneous than the TH and TD plans. For the cases with regional node involvement, the average mean doses administered to the heart were 9.2 (± 5.2) and 8.8 (± 3.0) Gy in the VMAT and TH plans compared with 11.9 (± 6.4) and 11.8 (± 9.2) Gy for the 3DCRT and TD plans, respectively, with slightly higher doses given to the contralateral lung or breast or both. On average, the total monitor units for VMAT plans are 11.6% of those TH plans. Our studies have shown that VMAT and TH plans offer certain dosimetric advantages over fixed-field IMRT plans for advanced breast cancer requiring regional nodal treatment. However, for early-stage breast cancer fixed-field radiotherapy is potentially more beneficial in terms of OAR sparing. 相似文献
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《Medical Dosimetry》2020,45(4):e9-e16
Whole breast radiotherapy (WBRT) after breast conserving surgery is the standard treatment to prevent recurrence and metastasis of early stage breast cancer. This study aims to compare seven WBRT techniques including conventional tangential, field-in-field (FIF), hybrid intensity-modulated radiotherapy (IMRT), IMRT, standard volumetric modulated arc therapy (STD-VMAT), noncoplanar VMAT (NC-VMAT), and multiple arc VMAT (MA-VMAT). Fifteen patients who were previously diagnosed with left-sided early stage breast cancer and treated in our clinic were selected for this study. WBRT plans were created for these patients and were evaluated based on target coverage and normal tissue toxicities. All techniques produced clinically acceptable WBRT plans. STD-VMAT delivered the lowest mean dose (1.1 ± 0.3 Gy) and the lowest maximum dose (7.3 ± 4.9 Gy) to contralateral breast, and the second lowest lifetime attributable risk (LAR) (4.1 ± 1.4%) of secondary contralateral breast cancer. MA-VMAT delivered the lowest mean dose to lungs (4.9 ± 0.9 Gy) and heart (5.5 ± 1.2 Gy), exhibited the lowest LAR (1.7 ± 0.3%) of secondary lung cancer, normal tissue complication probability (NTCP) (1.2 ± 0.2%) of pneumonitis, risk of coronary events (RCE) (10.3 ± 2.7%), and LAR (3.9 ± 1.3%) of secondary contralateral breast cancer. NC-VMAT plans provided the most conformal target coverage, the lowest maximum lung dose (46.2 ± 4.1 Gy) and heart dose (41.1 ± 5.4 Gy), and the second lowest LAR (1.8 ± 0.4%) of secondary lung cancer and RCE (10.5 ± 2.8%). MA-VMAT and NC-VMAT could be the preferred techniques for early stage breast cancer patients after breast conserving surgery. 相似文献