■这项研究的目的是调查,从剂量学的角度来看,自由呼吸(FB)期间的螺旋扫描疗法(HT)是否可以作为治疗无法遵守深吸气屏气(DIBH)技术的左侧乳腺癌患者的替代技术。
■为此,利用了20例仅在FB和DIBH期获得的左乳癌患者的CT图像。左乳房轮廓为目标体积,而心脏,LAD,同侧和对侧肺,在DIBH和FB获得的CT图像上,对侧乳房轮廓为有风险的器官。在DIBH(VMAT-DIBH)中获得的CT扫描上进行了体积调制电弧治疗(VMAT)技术的计划,同时使用HT技术对FB(HT-FB)中获得的CT扫描进行计划。随后,在目标覆盖率和正常组织保存方面对计划进行了剂量学比较。
■两种技术均达到了预期的目标覆盖率;然而,就D2、Vpres值而言,符合数量(CN),和均匀性指数(HI),HT-FB技术被发现是优越的。虽然两种技术的心脏平均剂量相似,在HT-FB技术生成的计划中,LAD和左肺的剂量被发现是优越的.当比较对侧乳房和右肺保护时,发现VMAT-DIBH技术明显优越。
■与VMAT-DIBH技术相比,已观察到使用HT-FB技术治疗仅左乳患者可提供类似的心脏保护以及更好的LAD和同侧肺保护,而不会损害目标覆盖率。然而,当使用HT-FB技术时,应仔细评估对侧肺和对侧乳房的剂量。
UNASSIGNED: The aim of this study is to investigate, from a dosimetric perspective, whether helical Tomotherapy (HT) during free breathing (FB) can serve as an alternative technique for treating left-sided breast cancer patients who are unable to comply with the deep inspiration breath hold (DIBH) technique.
UNASSIGNED: For this purpose, the CT images of 20 left breast-only cancer patients acquired in both FB and DIBH phases were utilized. The left breast was contoured as the target volume, while the heart, LAD, ipsilateral and contralateral lungs, and contralateral breast were contoured as organs at risk on the CT images obtained in both DIBH and FB. Planning with the volumetric modulated arc therapy (VMAT) technique was performed on the CT scans obtained in the DIBH (VMAT-DIBH), while planning with the HT technique was carried out on the CT scans obtained in the FB (HT-FB). Subsequently, dosimetric comparison of the plans were done in terms of target coverage and preservation of normal tissues.
UNASSIGNED: Both techniques achieved the desired target coverage; however, in terms of D2, Vpres values, Conformity Number (CN), and Homogeneity Index (HI), the HT-FB technique was found to be superior. While the mean doses to the heart were similar for both techniques, doses to the LAD and left lung were found to be superior in plans generated with the HT-FB technique. When compared in terms of contralateral breast and right lung protection, VMAT-DIBH technique was found to be significantly superior.
UNASSIGNED: The treatment of left breast-only patients with the HT-FB technique has been observed to provide similar heart protection and better LAD and ipsilateral lung protection compared to the VMAT-DIBH technique without compromising target coverage. However, when the HT-FB technique is used, doses to the contralateral lung and contralateral breast should be carefully evaluated.