左侧乳腺癌放疗深吸气屏气技术降低心脏剂量
Cardiac Dose Reduction with Deep-Inspiratory Breath Hold Technique of Radiotherapy for Left-Sided Breast Cancer.
作者信息
Sripathi Lalitha Kameshwari, Ahlawat Parveen, Simson David K, Khadanga Chira Ranjan, Kamarsu Lakshmipathi, Surana Shital Kumar, Arasu Kavi, Singh Harpreet
机构信息
Department of Radiation Oncology, Action Cancer Hospital, New Delhi, India.
Department of Radiation Oncology, Krishna Institute of Medical Sciences, Hyderabad, Telangana, India.
出版信息
J Med Phys. 2017 Jul-Sep;42(3):123-127. doi: 10.4103/jmp.JMP_139_16.
INTRODUCTION
Different techniques of radiation therapy have been studied to reduce the cardiac dose in left breast cancer.
AIM
In this prospective dosimetric study, the doses to heart as well as other organs at risk (OAR) were compared between free-breathing (FB) and deep inspiratory breath hold (DIBH) techniques in intensity modulated radiotherapy (IMRT) and opposed-tangent three-dimensional radiotherapy (3DCRT) plans.
MATERIALS AND METHODS
Fifteen patients with left-sided breast cancer underwent computed tomography simulation and images were obtained in both FB and DIBH. Radiotherapy plans were generated with 3DCRT and IMRT techniques in FB and DIBH images in each patient. Target coverage, conformity index, homogeneity index, and mean dose to heart (Heart D), left lung, left anterior descending artery (LAD) and right breast were compared between the four plans using the Wilcoxon signed rank test.
RESULTS
Target coverage was adequate with both 3DCRT and IMRT plans, but IMRT plans showed better conformity and homogeneity. A statistically significant dose reduction of all OARs was found with DIBH. 3DCRT decreased the Heart D by 53.5% (7.1 vs. 3.3 Gy) and mean dose to LAD by 28% compared to 3DCRT. IMRT further lowered mean LAD dose by 18%. Heart D was lower with 3DCRT over IMRT (3.3 vs. 10.2 Gy). Mean dose to the contralateral breast was also lower with 3DCRT over IMRT (0.32 vs. 3.35 Gy). Mean dose and the V of ipsilateral lung were lower with 3DCRT over IMRT (13.78 vs. 18.9 Gy) and (25.16 vs. 32.95%), respectively.
CONCLUSIONS
3DCRT provided excellent dosimetric results in patients with left-sided breast cancer without the need for IMRT.
引言
为降低左侧乳腺癌的心脏受量，人们对不同的放射治疗技术进行了研究。
目的
在这项前瞻性剂量学研究中，比较了在调强放射治疗（IMRT）和对穿切线三维放射治疗（3DCRT）计划中，自由呼吸（FB）和深吸气屏气（DIBH）技术下心脏以及其他危及器官（OAR）的受量。
材料与方法
15例左侧乳腺癌患者接受了计算机断层扫描模拟，在自由呼吸和深吸气屏气状态下均获取了图像。对每位患者在自由呼吸和深吸气屏气图像上分别采用3DCRT和IMRT技术生成放射治疗计划。使用Wilcoxon符号秩和检验比较了四种计划之间的靶区覆盖度、适形指数、均匀性指数以及心脏平均受量（心脏D）、左肺、左前降支动脉（LAD）和右乳的情况。
结果
3DCRT和IMRT计划的靶区覆盖均足够，但IMRT计划显示出更好的适形性和均匀性。深吸气屏气状态下所有危及器官的受量均有统计学意义的降低。与自由呼吸状态下的3DCRT相比，深吸气屏气状态下的3DCRT使心脏D降低了53.5%（7.1 Gy对3.3 Gy），LAD平均受量降低了28%。IMRT使LAD平均受量进一步降低了18%。自由呼吸状态下的3DCRT的心脏D低于IMRT（3.3 Gy对10.2 Gy）。自由呼吸状态下的3DCRT对侧乳腺的平均受量也低于IMRT（0.32 Gy对3.35 Gy）。自由呼吸状态下的3DCRT同侧肺的平均受量和V值均低于IMRT（13.78 Gy对18.9 Gy）和（25.16%对32.95%）。
结论
对于左侧乳腺癌患者，3DCRT无需IMRT即可提供出色的剂量学结果。
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