Comsa Daria, Barnett Erin, Le Ken, Mohamoud Gulaid, Zaremski Dana, Fenkell Louis, Kassam Zahra
Medical Physics, Radiation Medicine Program, Stronach Regional Cancer Centre, Southlake Regional Health Centre, Newmarket, Ontario, Canada; Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Medical Physics, Radiation Medicine Program, Stronach Regional Cancer Centre, Southlake Regional Health Centre, Newmarket, Ontario, Canada.
Pract Radiat Oncol. 2014 Sep-Oct;4(5):298-305. doi: 10.1016/j.prro.2013.10.006. Epub 2013 Dec 10.
Practical aspects of introducing moderate deep inspiration breath hold (mDIBH) for treatment of left breast cancer in a regional cancer program in terms of workflow and treatment delivery requirements are described. Differences in heart and lung doses between free breathing (FB) and mDIBH plans are presented as well as heart position reproducibility and resulting dosimetric impact using cone beam computed tomography (CBCT).
A mDIBH process was established. Therapists observed duration and quantity of breath holds required for setup, imaging, and beam delivery during treatment. Treatment plans were generated on the FB and mDIBH CT datasets allowing comparison of heart and lung dose-volume data for 50 patients. Five consecutive CBCT images were used to measure the distance between the heart and chest wall for 5 patients. Estimates of dose to the translated heart were then made with the treatment planning system.
When compared with FB delivery, mDIBH treatment time for tangents and boosts increased by 5 minutes, while 3- or 4-field techniques increased by 10 minutes. Differences in heart dose D10 cc, mean, V30 and V10 were statistically significant between the FB and mDIBH tangents and 3- or 4-field treatment plans. Statistically significant differences in V20, V10, V5, and mean lung doses were observed for 3- and 4-field FB and mDIBH plans. Differences between lung V5 dose metrics for FB and mDIBH 2-field plans were statistically significant. Interfraction mean translations in heart position coronally ranged from -6.2 to 2.6 mm and resulted in non-negligible increases in the heart dose.
Moderate deep inspiration breath hold has been successfully implemented in our regional cancer center for treatment of left breast cancer and is now a standard practice. This change in practice from FB to mDIBH treatment has not impacted our ability to meet provincial guidelines for patient throughput.
描述在区域癌症项目中引入中度深吸气屏气（mDIBH）用于治疗左乳腺癌在工作流程和治疗交付要求方面的实际情况。展示自由呼吸（FB）和mDIBH计划之间心脏和肺部剂量的差异，以及使用锥形束计算机断层扫描（CBCT）测量的心脏位置重复性和由此产生的剂量学影响。
建立了mDIBH流程。治疗师观察治疗期间设置、成像和射束交付所需的屏气持续时间和次数。在FB和mDIBH CT数据集上生成治疗计划，以便比较50例患者的心脏和肺部剂量体积数据。使用五例患者的连续五幅CBCT图像测量心脏与胸壁之间的距离。然后用治疗计划系统估计平移后心脏的剂量。
与FB治疗相比，切线野和加量野的mDIBH治疗时间增加了5分钟，而三野或四野技术增加了10分钟。FB和mDIBH切线野以及三野或四野治疗计划之间，心脏剂量D10 cc、平均值、V30和V10的差异具有统计学意义。对于三野和四野FB及mDIBH计划，观察到V20、V10、V5和平均肺部剂量存在统计学显著差异。FB和mDIBH两野计划的肺部V5剂量指标之间的差异具有统计学意义。心脏位置在冠状面的分次间平均平移范围为-6.2至2.6 mm，并导致心脏剂量出现不可忽略的增加。
中度深吸气屏气已在我们的区域癌症中心成功实施，用于治疗左乳腺癌，现已成为标准做法。从FB治疗改为mDIBH治疗这一实践变化并未影响我们满足省级患者吞吐量指南的能力。
