Dosimetric comparison of moderate deep inspiration breath-hold and free-breathing intensity-modulated radiotherapy for left-sided breast cancer

PurposeThis study determined the dosimetric comparison of moderate deep inspiration breath-hold using active breathing control and free-breathing intensity-modulated radiotherapy (IMRT) after breast-conserving surgery for left-sided breast cancer.Patients and methodsThirty-one patients were enrolled. One free breathe and two moderate deep inspiration breath-hold images were obtained. A field-in-field-IMRT free-breathing plan and two field-in-field-IMRT moderate deep inspiration breath-holding plans were compared in the dosimetry to target volume coverage of the glandular breast tissue and organs at risks for each patient.ResultsThe breath-holding time under moderate deep inspiration extended significantly after breathing training (P < 0.05). There was no significant difference between the free-breathing and moderate deep inspiration breath-holding in the target volume coverage. The volume of the ipsilateral lung in the free-breathing technique were significantly smaller than the moderate deep inspiration breath-holding techniques (P < 0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans. There were no significant differences in target volume coverage between the three plans for the field-in-field-IMRT (all P > 0.05). The dose to ipsilateral lung, coronary artery and heart in the field-in-field-IMRT were significantly lower for the free-breathing plan than for the two moderate deep inspiration breath-holding plans (all P < 0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans.ConclusionThe whole-breast field-in-field-IMRT under moderate deep inspiration breath-hold with active breathing control after breast-conserving surgery in left-sided breast cancer can reduce the irradiation volume and dose to organs at risks. There are no significant differences between various moderate deep inspiration breath-holding states in the dosimetry of irradiation to the field-in-field-IMRT target volume coverage and organs at risks.     

自主呼吸控制在乳腺癌术后放疗中的应用研究

目的 探讨自主呼吸控制（ABC）技术在乳腺癌术后放疗中的意义.方法 对22例行保乳术的早期乳腺癌患者（10例左侧,12例右侧）行术后全乳放疗并配合使用ABC技术.对每例患者在自由呼吸（FB）和75%适度深吸气（mDIBH）状态下分别行CT扫描.治疗计划系统设计优化放疗计划,每例患者做2个计划,处方剂量1.8 Gy/次,25次.比较各计划全肺平均受量（MLD）、全肺接受20Gy的体积（V20）、患侧肺V20、左侧乳腺癌患者心脏V30和心脏平均受量（Dmean）等参数.结果 22例患者患侧肺V20,FB时平均为17.0%,mDIBH时平均为16.2%,降低0.8%（t=3.63,P=0.002）;FB时双肺V20平均为8.7%,mDIBH时平均为8.0%,降低0.6%（t=2.78,P=0.011）.10例左侧患者心脏V30,FB时平均为6.1%,mDIBH时平均为3.8%,降低2.3%（t=6.50,P＜0.01）;心脏Dmean由449.58cGy降为332.79cGy（t=5.94,P＜0.01）.结论 乳腺癌术后全乳切线放疗中配合ABC技术使用mDIBH方法控制呼吸不但可减少呼吸运动对乳腺靶区的影响,而且可减少肺和心脏受照体积和剂量,从而大大减轻了对肺和心脏的放射损伤.     

Contribution of respiratory gating techniques for optimization of breast cancer radiotherapy

A comparative, nonrandomized, multicenter, and prospective analysis were performed between April 2004 and June 2008 in 20 French centers in order to compare clinical aspects of respiratory-gated conformal radiotherapy (RGRT) during breast cancer irradiation versus conventional conformal radiotherapy. The final results based on 233 evaluable patients at 48 months confirm the feasibility and good reproducibility of the RGRT systems. The main results demonstrated a marked reduction of dosimetric parameters predictive of lungs and cardiac toxicities in the RGRT group; especially the dose delivered to the heart during irradiation of the left breast; mostly observed with deep inspiration breath-hold techniques.     

左侧乳腺癌保乳术后放疗采用深吸气屏气技术肺部剂量Meta分析

目的:通过Meta分析探究左侧乳腺癌保乳术后放疗使用深吸气屏气技术对左肺剂量的影响。方法:2020年11月01日前检索PubMed、EMBASE、Web of Science寻找符合纳入标准的期刊文章,评价指标为左肺V20及左肺Dmean,通过Stata 12.0对提取的研究数据行Meta分析。结果:纳入20篇文献,共663例患者,异质性分析结果I2 检验(I-squared=69.5%)及Q检验(P=0.000)提示纳入20项研究间异质性较大。亚组分析结果:40例及以上组I2检验（I-squared=0%）及Q检验(P=0.909)提示各研究间无异质性;40例以下组I2检验（I-squared=76.8%）及Q检验(P=0.000) 提示异质性显著,说明异质性来源可能为样本量过小。最终对40例及以上组7项研究进行效应量合并,左肺V20在DIBH与自由呼吸（FB）两组间差异具有统计学意义［SMD=-0.28,95%CI（-0.41,-0.15）,Z=4.16,P=0.000］;左肺Dmean在DIBH与FB两组间差异具有统计学意义［SMD=-0.20,95%CI（-0.33,-0.07）,Z=2.96,P=0.003］。Egger回归检验结果提示本研究不存在明显的发表偏倚V20（P=0.971>0.05）及Dmean（P=0.666>0.05）。结论:左侧乳腺癌保乳术后放疗使用DIBH技术可以降低肺部照射剂量,从而减少放射性肺炎的发生概率,具有一定的临床价值。     

Failure free survival following brachytherapy alone for prostate cancer: comparison with external beam radiotherapy.

BACKGROUND AND PURPOSE: To compare failure free survival (FFS) for brachytherapy (BT) alone and external beam radiotherapy (EBXRT) alone. MATERIALS AND METHODS: Between 12/88 and 12/95, 1527 and 695 T(1) or T(2) Nx-No Mo prostate cancer patients (from the Arizona Oncology Services database) were treated with either EBXRT or BT, respectively. The median age was 74 years. Median follow-up for EBXRT and BT patients was 41.3 and 51.3 months, respectively. RESULTS: Overall FFS at 5 years for EBXRT and BT were 69 and 71%, respectively (P=0.91). No significant difference in FFS at 5 years was observed between EBXRT and BT for either T(1) (78 vs. 83%, P=0.47) or T(2) (67 vs. 67%, P=0.89) tumours. Superior outcomes for Gleason 8-10 lesions treated with EBXRT vs. BT (5 years FFS 52 vs. 28%, P=0.04) were observed; outcomes for lower grade lesions when analysed by Gleason score alone did not significantly differ according to treatment received. Patients with initial PSA values 10-20 ng/dl had an improved FFS with EBXRT vs. BT (70 vs. 53%, P=0.001); outcomes for patients with initial PSA ranges 0-4 ng/dl, >4-10 ng/dl and >20 ng/dl did not differ significantly with treatment received. CONCLUSIONS: EBXRT and BT appear to be equally efficacious for low-risk patients having T(1)/T(2) disease with Gleason scores <6 and PSA <10 ng/dl. Patients with Gleason scores 8-10 or PSA >10 ng/dl-<20 ng/dl) appear to fare worse with BT alone compared with EBXRT. Neither EBXRT nor BT were particularly effective for patients with a presenting PSA >20 ng/dl.     

CT-Sim技术在乳腺癌放射治疗中的应用

用大恒STAR 2 0 0 0三维放射治疗系统、GE双螺旋CT、国产北医BJ 6B型加速器对乳腺癌患者实施精确定位、虚拟计划设计、射野间无缝连接照射 ,可提高患者重复摆位的精度 ,定位时间短 ,射野间衔接好 ,患者皮肤反应轻 ,放射性肺炎发生率明显下降。     

左侧乳腺癌保乳术后采用深吸气屏气放疗的心脏剂量学分析

目的 探究左侧乳腺癌保乳术后放疗患者采用深吸气屏气(DIBH)技术对心脏剂量的改善情况,分析可能影响心脏剂量的解剖因素。方法 前瞻性入组 15例左侧乳腺癌保乳术后行全乳放疗患者,符合呼吸控制要求。分别在自由呼吸(FB)和DIBH状态下进行2次模拟CT扫描,在DIBH图像上制定全乳放疗计划。比较FB和DIBH状态下心肺位置和体积变化以及心肺剂量差异,探究FB状态下各解剖因素与心脏剂量的相关性。对计数资料组间行非参数Wilcoxon秩和检验,双变量相关分析采用Pearson法。结果 DIBH与FB状态下心脏体积相似(P=0.773),而双肺体积明显增加(P=0.001)。心脏、冠脉左前降支、左心室、右心室和左肺 Dmean、Dmax和V5—V40均明显降低(P<0.05)。DIBH使肺体积增加越显著,心脏平均剂量下降幅度越大。FB状态下乳腺体积、心肺体积比、乳腺下界与心脏下界距离、最大心脏切缘距离分别与心脏剂量呈线性相关,其中心肺体积比、最大心脏切缘距离与心脏剂量具有独立相关性。结论 左侧乳腺癌保乳术后采用DIBH技术行全乳放疗较FB状态明显降低心肺剂量。肺体积的变化是改善心脏相对解剖位置的基础。心肺体积比、最大心脏切缘距离或许可以作为进行DIBH技术治疗的参考标准。     

宫颈癌术后快速旋转调强放疗和三维适形放疗计划的对比研究

目的 探讨宫颈癌术后快速旋转调强放疗（RapidArc）和三维适形放疗（3D-CRT）计划靶区及其周围危及器官（OAR）受照剂量的差异。方法 随机选择10 例宫颈癌术后患者,进行CT 扫描、靶区（PTV）和OAR的勾画,处方剂量50Gy。分别进行RapidArc和3D-CRT计划设计,计算并比较两种计划的PTV剂量均匀度指数（HI）、适形度指数（CI）、最大受照剂量（PTV Dmax）、最小受照剂量（PTV Dmin）、平均受照剂量（PTV Dmean）和OAR受照体积。结果 RapidArc计划的CI及PTV Dmean均优于3D-CRT计划;RapidArc计划对OAR（膀胱V50,直肠V40、V50,左、右股骨头V20）的保护优于3D-CRT计划（P＜0.05）。两种计划的PTV Dmax、PTV Dmin、HI和OAR受照体积（小肠V10、V20、V30、V40、V50,直肠V10、V20、V30, 膀胱V10、V20、V30、V40,左、右股骨头V10、V30、V40、V50）的差异均无统计学意义（P＞0.05）。结论 宫颈癌术后辅助放疗中,RapidArc计划在靶区CI和PTV Dmean方面均优于3D-CRT,同时RapidArc计划在正常组织保护上也有一定的优势。     

Dosimetric and clinical advantages of deep inspiration breath-hold (DIBH) during radiotherapy of breast cancer

Background

To investigate the potential dosimetric and clinical benefits of Deep Inspiration Breath-Hold (DIBH) technique during radiotherapy of breast cancer compared with Free Breathing (FB).

Methods

Eight left-sided breast cancer patients underwent a supervised breath hold during treatment. For each patient, two CT scans were acquired with and without breath hold, and virtual simulation was performed for conventional tangential fields, utilizing 6 or 15 MV photon fields. The resulting dose–volume histograms were calculated, and the volumes of heart/lung irradiated to given doses were assessed. The left anterior descending coronary artery (LAD) mean and maximum doses were calculated, together with tumour control probability (TCP) and normal tissue complication probabilities (NTCP) for lung and heart.

Results

For all patients a reduction of at least 16% in lung mean dose and at least 20% in irradiated pulmonary volumes was observed when DIBH was applied. Heart and LAD maximum doses were decreased by more than 78% with DIBH. The NTCP values for pneumonitis and long term cardiac mortality were also reduced by about 11% with DIBH. The NTCP values for pericarditis were zero for both DIBH and FB.

Conclusion

Delivering radiation in DIBH conditions the dose to the surrounding normal structures could be reduced, in particular heart, LAD and lung, due to increased distance between target and heart, and to reduced lung density.

     

固定铅门调强技术对乳腺癌术后放射治疗计划设计的作用

目的：近年来固定铅门技术在调强治疗计划设计中已经被广泛使用,本文对比固定铅门（ Fixed jaw）和动态铅门（Jaw tracking）两种技术在乳腺癌调强放射治疗计划设计中的优缺点,探讨固定铅门调强放射治疗技术对乳腺癌治疗计划设计的作用。方法：固定铅门技术是在常规调强放射治疗技术的基础上,人为限定铅门和光栅的作用范围,使某些照射野作用于特定的治疗区域,从而期望得到更好的治疗计划方案。本文选取21例以往进行过 Jaw tracking 技术调强放射治疗的病例,应用 Fixed jaw 技术重新进行计划设计。对应用两种技术的调强放射治疗计划靶区的 Dmean ,Dmin ,Dmax 和患侧肺以及心脏的受照剂量进行对比。同时也对靶区的均匀性指数和适形度指数做了对比。结果：在保证靶区处方剂量的前提下,固定铅门技术相比于动态铅门技术可以明显降低肺 V