To evaluate the clinical feasibility and dosimetric benefits of a novel gantry‐static couch‐motion (GsCM) technique for external beam photon boost treatment of lumpectomy cavity in patients with early‐stage breast cancer in comparison to three‐dimensional conformal radiotherapy (3D‐CRT), wedge pair in supine position (WPS), and wedge pair in decubitus position (WPD) techniques. A retrospective review was conducted on breast patients (right breast, n = 10 and left breast, n = 10) who received 10 Gy boost after 50 Gy to whole breast. The treatment plans were generated using an isocentric‐based GsCM technique (a VMAT type planning approach) integrating couch rotational motion at static gantry positions. Static fields for each tangential side were merged using a Matlab^® script and delivered automatically within the Varian Truebeam^TM STx in Developer Mode application as a VMAT arc (wide‐angular medial and short‐angular lateral arcs). The dosimetric accuracy of the plan delivery was evaluated by ion chamber array measurements in phantom. For both right and left breast boost GsCM, 3D‐CRT, WPS, and WPD all provided an adequate coverage to PTV. GsCM significantly reduced the ipsilateral lung V30% for right side (mean, 80%) and left side (mean, 70%). Heart V5% reduced by 90% (mean) for right and 80% (mean) for left side. Ipsilateral breast V50% and mean dose were comparable for all techniques but for GsCM, V100% reduced by 50% (mean) for right and left side. The automated delivery of both arcs was under 2 min as compared to delivering individual fields (30 ± 5 min). The gamma analysis using 2 mm distance to agreement (DTA) and 2% dose difference (DD) was 98 ± 1.5% for all 20 plans. The GsCM technique facilitates coronal plane dose delivery appropriate for deep‐seated breast boost cavities, with sufficient dose conformity of target volume paired with sparing of the OARs.

中文翻译：

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龙门静态卧推运动（GsCM）技术在乳房增强放射治疗中的剂量学优势：降低高风险器官的剂量并改善剂量学指标。

与三维保形放射疗法（3D-CRT）相比，评估新颖的龙门静态卧推运动（GsCM）技术对早期乳腺癌患者的肿块切除腔进行外束光子增强治疗的临床可行性和剂量学益处），仰卧位楔形对（WPS）和卧位楔形对（WPD）技术。回顾性回顾了对50 Gy的全乳患者进行了10 Gy增强的乳腺癌患者（右乳房，n = 10，左乳房，n = 10）。使用基于等心点的GsCM技术（VMAT类型规划方法）生成治疗计划，该技术整合了固定机架位置的卧榻旋转运动。每个切侧静态字段使用Matlab的合并^®脚本并在Varian Truebeam ^TM中自动交付在开发人员模式应用程序中，STx作为VMAT弧（广角内侧和短角外侧弧）。通过幻影中的离子室阵列测量来评估计划交付的剂量学准确性。对于左右乳房增强，GsCM，3D-CRT，WPS和WPD都为PTV提供了足够的覆盖范围。GsCM显着降低了右侧（平均80％）和左侧（平均70％）的同侧肺V30％。心脏V5％的右侧减少90％（平均），左侧减少80％（平均）。对于所有技术，同侧乳房的V50％和平均剂量是可比较的，但对于GsCM，右侧和左侧的V100％降低了50％（平均值）。与交付单个区域（30±5分钟）相比，两个电弧的自动交付不到2分钟。对于所有20个方案，使用2 mm一致距离（DTA）和2％剂量差异（DD）进行的伽马分析为98±1.5％。