摘要
目的比较左侧乳腺癌保乳术后常规放疗(CR)、三维适形放疗(3D—CRT)、四野及五野调强放疗(IMRT)靶区剂量分布差异。方法随机选择14例左侧乳腺癌保乳术后患者,为每例患者设计上述4种照射技术的治疗计划。处方剂量为50Gy/25次。所有计划都使90%-95%靶区体积达到处方剂量要求。分别比较靶区剂量适形性、均匀性以及心肺所受剂量。结果3D—CRT和IMRT靶区剂量均匀度和适形度明显优于CR;IM—RT技术在正常组织的保护方面优于3D—CRT,3D—CRT技术优于CR。IMRT技术使患侧肺、心脏高剂量区体积降低,低剂量区增加,使对侧肺平均受照剂量增加。与四野[MRT相比,五野IMRT虽然改善了靶区的均匀性及适形度,但增加了患侧肺V5、V10及右肺平均剂量,而心脏及患侧肺高剂量区却无明显改善。结论与CR相比,3D—CRT和IMRT能够明显改善靶区均匀性和适形度,降低了患侧肺、心脏高剂量受照体积;在降低心脏及患侧肺高剂量体积方面,IMRT明显优于3D—CRT;四野IMRT是取代CR的最佳选择。
Objective To evaluate the benefit of conventional radiotherapy (CR), three dimensional conformal radiotherapy (3D- CRT) and intensity -modulated radiotherapy (IMRT) in target dose uniformity and normal tissue sparing for left breast cancer. Methods For each of 14 randomly chosen patients, 4 plans were designed for 4 irradiation techniques. The prescribed dose was 50 Gy/25f, 90% - 95% of the planning target volume received this dose. Target dose homogeneity and conformity, and dose received by heart and lung were compared. Results For 2 IMRT techniques and 3D- CRT technique, the dose homogeneity and conformity in target were improved compared with CR. The dose homogeneity and conformity in target were best for five - field IMRT. Normal tissue protection for 3D - CRT was better than CR, and better than 3D - CRT for IMRT. For IMRT, high dose volume for ipsilateral lung and heart was decreased while low dose volume and average dose of con - lung were increased. Low dose volume of ipsilateral lung and heart was greatly increased for five - field IMRT, but high dose volume of heart and ipsilateral lung was not decreased significantly compared with four -field IMRT. Conclusions Compared with CR, 3D - CRT and IMRT can improve the homogeneity and conformity of planning target volume ( PTV ) , reduce the irradiated volumes of ipsiiateral lung and heart receiving fairly high dose, while IMRT is better than 3D - CRT. For current radiotherapy practice, four - field IMRT is the appropriate choice for patients with left breast cancer after breast -conserving surgery.
出处
《徐州医学院学报》
CAS
2011年第10期666-669,共4页
Acta Academiae Medicinae Xuzhou
基金
基金项目:江苏省卫生厅科技项目(H201021)
徐州市科技项目(XF10C078)
关键词
乳腺肿瘤
常规放疗
三维适形放疗
调强放疗
breast neoplasms
conventional radiotherapy
three dimensional conformal radiotherapy
intensity -modulated radiotherapy