Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Beijing, China.
J Appl Clin Med Phys. 2012 Nov 8;13(6):3769. doi: 10.1120/jacmp.v13i6.3769.
The purpose of this study is to apply noncoplanar intensity-modulated radiation therapy (Nonco_IMRT) to young female patients with mediastinal lymphoma. Nonco_IMRT was evaluated through a planning comparison study with coplanar IMRT (Co_IMRT) and conventional anteroposterior and posteroanterior fields (AP-PA) plans. Co_IMRT was performed with five equally spaced beams starting from a gantry angle of 216°. Nonco_IMRT used two noncoplanar beams in the sagittal plane to replace the Co_IMRT beams that directly irradiated the breasts. Nineteen young female patients were enrolled in the retrospective study. Dose coverage of the planning target volume (PTV) and the dose delivered to organs at risk (OARs) were analyzed. For all patients, PTV coverage and heart V30 were similar between the two IMRT techniques (p > 0.05). Compared to Co_IMRT, the mean dose delivered and regions receiving a low radiation dose were significantly reduced for bilateral breasts and lungs in Nonco_IMRT (p < 0.05). Breast V5 and lung V5 were relatively reduced by 21% and 12%, respectively. Compared with the conventional AP-PA plan, Nonco_IMRT had better PTV coverage and OARs sparing, except for being larger in V5 to breast and lung. In IMRT for young female patients with mediastinal lymphoma, using of Nonco_IMRT significantly reduces the radiation dose to the breasts and lungs compared with Co_IMRT, and consequently reduces the risk of breast second cancer and pulmonary toxicity. Besides young female patients, Nonco_IMRT can also benefit other mediastinal lymphoma patients.
本研究旨在将非共面调强放射治疗（Nonco_IMRT）应用于纵隔淋巴瘤的年轻女性患者。通过与共面调强放射治疗（Co_IMRT）和传统前后野（AP-PA）计划的对比研究，对 Nonco_IMRT 进行了评估。Co_IMRT 采用 5 个等间距光束，从机架角度 216°开始。Nonco_IMRT 在矢状面使用两个非共面光束，以代替直接照射乳房的 Co_IMRT 光束。19 名年轻女性患者被纳入回顾性研究。分析了计划靶区（PTV）的剂量覆盖和危及器官（OAR）的剂量分布。对于所有患者，两种调强技术的 PTV 覆盖和心脏 V30 相似（p > 0.05）。与 Co_IMRT 相比，Nonco_IMRT 双侧乳房和肺部的平均剂量和低剂量照射区域显著降低（p < 0.05）。乳房 V5 和肺 V5 分别降低了 21%和 12%。与传统 AP-PA 方案相比，Nonco_IMRT 具有更好的 PTV 覆盖和 OAR 保护，除了乳房和肺 V5 更大。在纵隔淋巴瘤的年轻女性患者的调强放射治疗中，与 Co_IMRT 相比，Nonco_IMRT 显著降低了乳房和肺部的放射剂量，从而降低了乳腺癌二次发生和肺毒性的风险。除了年轻女性患者外，Nonco_IMRT 还可以使其他纵隔淋巴瘤患者受益。
