Harvard Radiation Oncology Program, Brigham & Women's Hospital, Department of Radiation Oncology, 75 Francis Street, Boston, MA 02215, USA.
Radiother Oncol. 2013 May;107(2):213-7. doi: 10.1016/j.radonc.2013.03.028. Epub 2013 May 3.
Delivery of post-mastectomy radiation (PMRT) in women with bilateral implants represents a technical challenge, particularly when attempting to cover regional lymph nodes. Intensity modulated proton therapy (IMPT) holds the potential to improve dose delivery and spare non-target tissues. The purpose of this study was to compare IMPT to three-dimensional (3D) conformal radiation following bilateral mastectomy and reconstruction.
Ten IMPT, 3D conformal photon/electron (P/E), and 3D photon (wide tangent) plans were created for 5 patients with breast cancer, all of whom had bilateral breast implants. Using RTOG guidelines, a physician delineated contours for both target volumes and organs-at-risk. Plans were designed to achieve 95% coverage of all targets (chest wall, IMN, SCV, axilla) to a dose of 50.4 Gy or Gy (RBE) while maximally sparing organs-at-risk.
IMPT plans conferred similar target volume coverage with enhanced homogeneity. Both mean heart and lung doses using IMPT were significantly decreased compared to both P/E and wide tangent planning.
IMPT provides improved homogeneity to the chest wall and regional lymphatics in the post-mastectomy setting with improved sparing of surrounding normal structures for woman with reconstructed breasts. IMPT may enable women with mastectomy to undergo radiation therapy without the need for delay in breast reconstruction.
在双侧植入物的女性中进行乳房切除术后放射治疗（PMRT）是一项技术挑战，尤其是在试图覆盖区域淋巴结时。强度调制质子治疗（IMPT）有可能改善剂量传递并保护非靶组织。本研究的目的是比较双侧乳房切除术后和重建后使用 IMPT 与三维（3D）适形放射治疗。
为 5 名乳腺癌患者中的每一位患者创建了 10 个 IMPT、3D 适形光子/电子（P/E）和 3D 光子（宽切线）计划，他们均有双侧乳房植入物。使用 RTOG 指南，医生对靶区和危及器官进行了轮廓勾画。设计计划的目的是实现所有靶区（胸壁、IMN、SCV、腋窝）的 95%覆盖率，剂量为 50.4 Gy 或等效生物剂量（RBE），同时最大限度地保护危及器官。
IMPT 计划提供了相似的靶区覆盖率，并提高了均匀性。与 P/E 和宽切线计划相比，IMPT 计划的平均心脏和肺剂量均显著降低。
在乳房切除术后的情况下，IMPT 为胸壁和区域淋巴结提供了更好的均匀性，同时为接受乳房重建的女性更好地保护了周围的正常结构。IMPT 可能使接受乳房切除术的女性无需延迟乳房重建即可接受放射治疗。
