Decreasing radiotoxicity to the heart, lungs, and contralateral breast has proven to lower the risk of secondary malignancy and improve overall outcomes when treating chest wall (CW) and regional lymph nodes in postmastectomy breast cancer patients. In this retrospective study, 11 postmastectomy patients were selected and planned with a novel hybrid treatment method and a traditional volumetric arc therapy (VMAT) approach for comparison. This hybrid technique was able to optimize tangential beams to minimize heart dose and the VMAT contribution to improve dose conformity around the planning target volume (PTV). Overall, this hybrid technique produced more homogenous target dose coverage and demonstrated a decrease of integral dose to organs at risk (OAR), while the VMAT technique demonstrated a higher affinity for maintaining dose conformity. Further observation of dose distributions also revealed that the hybrid plans were more effective in sparing low-dose spread to healthy tissue in both right- and left-sided cases. This observation was made evident by the reduction in heart V5 and D_mean, decreases in all parameters regarding the contralateral lung, as well as all values other than the V20 of the ipsilateral lung. This unique hybrid planning technique could present an alternative to standard intensity-modulated radiation therapy (IMRT) planning when treating postmastectomy CW and regional lymph nodes, as it has shown the capacity to decrease cardiac, lung, and contralateral breast toxicity while maintaining quality PTV coverage.

在治疗乳房切除术后乳腺癌患者的胸壁（CW）和局部淋巴结时，降低对心脏，肺和对侧乳房的放射毒性已被证明可以降低继发性恶性肿瘤的风险并改善总体结局。在这项回顾性研究中，选择并计划了11名乳房切除术后患者，并采用了一种新型的混合治疗方法和传统的容积弧治疗（VMAT）方法进行比较。这种混合技术能够优化切向光束以最小化心脏剂量，并通过VMAT改善规划目标体积（PTV）周围的剂量一致性。总的来说，这种混合技术产生了更均匀的目标剂量覆盖率，并证明了对处于危险中的器官（OAR）的积分剂量减少了，而VMAT技术证明了保持剂量一致性的更高亲和力。对剂量分布的进一步观察还表明，在右侧和左侧病例中，混合计划在减少低剂量向健康组织扩散方面更为有效。心脏V5和D的降低证明了这一发现_平均，与对侧肺有关的所有参数以及除同侧肺的V20以外的所有其他值_均降低。当治疗乳房切除术后连续波和局部淋巴结时，这种独特的混合计划技术可以替代标准强度调制放射治疗（IMRT）计划，因为它已经显示出减少心脏，肺和对侧乳房毒性的能力，同时又能保持高质量的PTV覆盖率。