Kairn T, Crowe S B
Genesis Cancer Care Queensland, Genesis Care, Brisbane, Australia.
Cancer Care Services, Royal Brisbane & Women's Hospital, Brisbane, Australia.
Australas Phys Eng Sci Med. 2019 Mar;42(1):227-233. doi: 10.1007/s13246-019-00725-w. Epub 2019 Mar 8.
The advantages, in terms of heart dose sparing, resulting from using a breath-hold technique when treating supine left breast radiotherapy patients are widely accepted, and increasing numbers of radiotherapy departments are implementing breath-hold techniques. However, due to differences in patient setup and treatment planning protocols between radiotherapy departments, it is important to assess the benefits of using a breath-hold technique within each department, before or during implementation. This study investigated the use of retrospective analysis of past patient treatment plans, as a means to identify the potential for breath-hold techniques to benefit patients. In-house "Treatment and Dose Assessor" code was used to complete a bulk retrospective evaluation of dose-volume metrics for 708 supine and 13 prone breast and chest wall radiotherapy treatments, that were planned using the same clinical protocols, which did not utilise a breath hold technique. For supine patients, results showed statistically significant differences between heart doses from left and right breast treatment plans, in the absence of significant differences between lung doses from left and right breast treatment plans, confirming the potential benefit of using a breath-hold technique for supine left breast radiotherapy patients. Fewer than 1% of the right breast treatment plans showed heart doses high enough to suggest a possible benefit from using a breath-hold technique. Approximately 50% of the prone left breast treatment plans included very low heart doses without intervention, and may therefore have shown no noticeable dosimetric benefit from the use of a breath hold. This study demonstrated the extent of information that can be obtained using retrospective data analysis, before or instead of obtaining multiple CT images of patients and completing a process of dual planning and prospective dose evaluation.
在治疗仰卧位左侧乳腺癌放疗患者时，采用屏气技术在心脏剂量 sparing 方面的优势已被广泛认可，越来越多的放疗科室正在实施屏气技术。然而，由于各放疗科室在患者摆位和治疗计划方案上存在差异，在实施前或实施过程中评估本部门使用屏气技术的益处非常重要。本研究调查了对过去患者治疗计划进行回顾性分析的方法，以此来确定屏气技术使患者受益的潜力。使用内部“治疗与剂量评估器”代码，对 708 例仰卧位和 13 例俯卧位乳腺及胸壁放疗治疗的剂量体积指标进行了大量回顾性评估，这些治疗计划采用相同的临床方案，未使用屏气技术。对于仰卧位患者，结果显示在左右乳腺治疗计划的心脏剂量之间存在统计学显著差异，而左右乳腺治疗计划的肺剂量之间无显著差异，这证实了屏气技术对仰卧位左侧乳腺癌放疗患者的潜在益处。不到 1%的右侧乳腺治疗计划显示心脏剂量高到足以表明使用屏气技术可能有益。大约 50%的俯卧位左侧乳腺治疗计划在无干预情况下心脏剂量非常低，因此可能未显示出使用屏气技术有明显的剂量学益处。本研究证明了在获取患者的多个 CT 图像并完成双重计划和前瞻性剂量评估过程之前或取而代之，使用回顾性数据分析可获得的信息范围。
