Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United States; Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United States.
Radiother Oncol. 2017 Oct;125(1):48-54. doi: 10.1016/j.radonc.2017.07.034. Epub 2017 Sep 13.
To compare heart and cardiac substructure radiation exposure using intensity-modulated radiotherapy (IMRT) vs. proton beam therapy (PBT) for patients with mid- to distal esophageal cancer who received chemoradiation therapy.
We identified 727 esophageal cancer patients who received IMRT (n=477) or PBT (n=250) from March 2004 to December 2015. All patients were treated to 50.4Gy with IMRT or to 50.4 cobalt Gray equivalents with PBT. IMRT and PBT dose-volume histograms (DVHs) of the whole heart, atria, ventricles, and four coronary arteries were compared. For PBT patients, passive scattering proton therapy (PSPT; n=237) and intensity-modulated proton therapy (IMPT; n=13) DVHs were compared.
Compared with IMRT, PBT resulted in significantly lower mean heart dose (MHD) and heart V5, V10, V20, V30, and V40as well as lower radiation exposure to the four chambers and four coronary arteries. Compared with PSPT, IMPT resulted in significantly lower heart V20, V30, and V40 but not MHD or heart V5 or V10. IMPT also resulted in significantly lower radiation doses to the left atrium, right atrium, left main coronary artery, and left circumflex artery, but not the left ventricle, right ventricle, left anterior descending artery, or right coronary artery. Factors associated with lower MHD included PBT (P<0.001), smaller planning target volume (PTV; P<0.001), and gastroesophageal junction (GEJ) tumor (P<0.001). Among PBT patients, factors associated with lower MHD included IMPT (P=0.038), beam arrangement other than AP/PA (P<0.001), smaller PTV (P<0.001), and GEJ tumor (P<0.001).
In patients with mid- to distal esophageal cancer, PBT results in significantly lower radiation exposure to the whole heart and cardiac substructures than IMRT. Long-term studies are necessary to determine how this cardiac sparing effect impacts the development of coronary artery disease and other cardiac complications.
比较中下段食管癌患者接受化放疗时，调强放疗（IMRT）与质子束放疗（PBT）的心脏和心脏亚结构辐射暴露。
我们从 2004 年 3 月至 2015 年 12 月共确定了 727 名接受 IMRT（n=477）或 PBT（n=250）治疗的食管癌患者。所有患者均接受 IMRT 50.4Gy 或 PBT 50.4 钴 Gray 等效照射。比较了全心脏、心房、心室和 4 支冠状动脉的 IMRT 和 PBT 剂量体积直方图（DVH）。对于 PBT 患者，比较了被动散射质子治疗（PSPT；n=237）和调强质子治疗（IMPT；n=13）的 DVH。
与 IMRT 相比，PBT 可显著降低平均心脏剂量（MHD）和心脏 V5、V10、V20、V30 和 V40，以及四个心腔和四支冠状动脉的辐射暴露。与 PSPT 相比，IMPT 可显著降低心脏 V20、V30 和 V40，但不降低 MHD 或心脏 V5 或 V10。IMPT 还可显著降低左心房、右心房、左主冠状动脉和左旋支冠状动脉的辐射剂量，但不降低左心室、右心室、左前降支或右冠状动脉的辐射剂量。与 MHD 降低相关的因素包括 PBT（P<0.001）、较小的计划靶区（PTV；P<0.001）和胃食管交界处（GEJ）肿瘤（P<0.001）。在 PBT 患者中，与 MHD 降低相关的因素包括 IMPT（P=0.038）、非前后位（AP/PA）布野（P<0.001）、较小的 PTV（P<0.001）和 GEJ 肿瘤（P<0.001）。
在中下段食管癌患者中，PBT 可显著降低全心脏和心脏亚结构的辐射暴露，优于 IMRT。需要进行长期研究以确定这种心脏保护作用如何影响冠状动脉疾病和其他心脏并发症的发展。
