摘要
目的评价乳腺癌全乳切除术后胸壁电子束照射的剂量学优势。方法选取42例乳腺癌保乳术后患者,应用Pinnacle7.4f计划系统分别为每例患者进行电子束照射计划和切线照射计划设计,胸壁处方剂量均为5000cGy/25次,用剂量直方图来比较两种计划中临床靶区和心脏、同侧肺的剂量学差异。结果乳腺癌全乳切除术后胸壁电子束照射计划靶区的Dmax为5562±61cGy,较胸壁切线照射计划的5402±82cGy高(t=6.10,P<0.05);胸壁电子束照射靶区均匀性也较胸壁切线照射计划好(1.18±0.03vs.1.13±0.18,t=6.50,P<0.05);但胸壁电子束照射计划靶区的适形指数更好(0.77±0.17vs.0.57±0.17,t=3.49,P<0.05)。胸壁电子束照射计划的肺V40、心脏最大剂量、心脏V30和心脏V40较胸壁切线照射计划小(5.86±3.68%vs.8.73±3.26%,t=-2.27,P<0.05;4839±388cGyvs.5095±176cGy,t=-2.32,P<0.05;2.58±1.50%vs.7.20±2.62%,t=-4.70,P<0.05;1.74±1.23%vs.4.20±2.51%,t=-3.50,P<0.05)。结论与胸壁切线照射计划相比较,左侧乳腺癌全乳切除术后胸壁电子束照射计划的适形性较好,并降低了心、肺的高剂量体积,但其均匀性较差。
Objective To evaluate the dosimetric advantages of postmastectomy electron-beam chest-wall irradiation after left mastectomy in patients with breast cancer. Methods Electron-beam chest-wall irradiation and tangential field irradiation were planned using Pinnacle7.4f planning systems for 42 patients with left breast cancer after mastectomy. The total prescribed dose for both plans was 5000 cGy/25 fractions. The dose volume histogram was used to compare the dosimetry of the clinical target volume （CTV） and the organs at risk such as the heart and ipsilateral lung. Results The maximum dose （Dmax） of the CTV of electron beam chest-wall irradiation plans was significantly higher than that of tangential field irradiation plans （5562±61 vs 5402±82 cGy,t=6.10,P0.05）. The CTV of the electron beam chest-wall irradiation plans showed better heterogeneity than that of the tangential field irradiation plans,with heterogeneity index of 1.18±0.03 and 1.13±0.18,respectively （t=6.50,P0. 05）. Electron beam chest-wall irradiation plans had also a better conformal index of the CTV than tangential field irradiation plans （0.77± 0.17 vs 0.57±0.17,t=3.49,P0.05）. The V40 of the ipsilateral lung,the maximum dose of the heart,V30 and V40 of the heart in the electron beam chest-wall irradiation plans were smaller than those of the tangential field irradiation plans [（5.86±3.68）% vs （8.73±3.26）%,t=-2.27,P0.05; 4839±388 cGy vs 5095±176 cGy,t=-2.32,P0.05; （2.58±1.50）% vs （7.20± 2.62）%,t=-4.70,P0.05; （1.74±1.23）% vs （4.20±2.51）%,t=-3.50,P0.05]. Conclusion Compared with the tangential field irradiation plans,electron-beam chest-wall irradiation has better coverage index of the CTV and can decrease the high-dose volume of the normal tissue,but shows a poorer habituation index of the CTV.
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2010年第12期2671-2674,共4页
Journal of Southern Medical University
基金
广东省科技计划社会发展项目2008B060600019
关键词
乳腺癌
放射治疗
电子束照射
breast cancer
radiation
electron-beam chest-wall irradiation
