早期乳腺癌患者保乳术后三维适形、调强放疗和混合调强3种放疗计划的比较分析

Comparison of 3D-conformal radiotherapy, intensity-modulated radiotherapy and hybrid intensity-modulated radiotherapy for breast cancer patients following breast-conserving surgery

目的比较三维适形(3D-CRT)、调强放疗(IMRT)和混合调强(h-IMRT)3种早期乳腺癌放疗计划。方法随机选取30例早期保乳术后患者(左侧15例,右侧15例),分别使用3D-CRT、IMRT和h-IMRT 3种放疗技术制定放疗计划。比较DVH剂量参数,包括剂量分布,剂量适形性,心脏以及患侧肺等危及器官的剂量分布,机器输出跳数,危及器官平均剂量。结果 IMRT及h-IMRT计划靶区剂量分布优于3D-CRT计划,其中双侧乳腺癌的V105%(%),平均剂量组间比较差异均有统计学意义(左侧:F=6.45、11.3,右侧:F=9.57、10.3;P<0.05)。正常组织受量:h-IMRT在患侧肺V20Gy(%)和V30Gy(%)上有优势(左侧:F=7.98、9.56,右侧:F=5.89、6.54;P<0.05);对于心脏,3D-CRT计划在V5Gy(%)上可以得到比IMRT及h-IMRT更低的剂量(左侧:F=3.8,P<0.05),此外,h-IMRT计划的V30Gy(%)优于其他两者(左侧:F=13.5,P<0.05)。h-IMRT计划所需机器跳数值介于3D-CRT和IMRT之间(左侧:F=10.89,右侧:F=12.34;P<0.05)。结论相比3D-CRT技术,IMRT和h-IMRT在保护危及器官能力上有显著提高。使用h-IMRT技术能获得比3D-CRT和IMRT更好的剂量学结果,更适合早期保乳术后患者的放射治疗。

Objective To compare 3D-conformal radiotherapy(3D-CRT), intensity-modulated radiotherapy(IMRT) and hybrid intensity-modulated radiotherapy(h-IMRT) for breast cancer patients following breast-conserving surgery. Methods Thirty patients with breast cancer(15 left, 15 right) receiving breast-conserving surgery were recruited. The therapeutic plans 3D-CRT,IMRT and h-IMRT were made respectively. The dose-volume parameters, including target coverage, homogeneity, doses to the organs at risk(heart, the contralateral lung and others) were compared among three plans. The mean doses of organs at risk were also evaluated. Results The IMRT and h-IMRT plans provided lower V105%(%) dose and better mean dose than 3D-CRT plans(left side: F= 6.45, 11.3, right side: F=9.57, 10.3; P<0.05). The ipsilateral lung received a volume of 20 Gy and 30 Gy for h-IMRT,which was significantly less than that for 3D-CRT or IMRT(left side: F=7.98, 9.56, right side: F=5.89, 6.54; P <0.05). The heart received V5Gy(%) dose for 3D-CRT, which was superior to those of IMRT and h-IMRT(left side: F=3.8, P<0.05). The low volume dose distribution of V30 Gy(%) in heart for h-IMRT was better than that for 3D-CRT and IMRT(left side: F=13.5, P<0.05). The total MUs of h-IMRT were between 3D-CRT and IMRT(left side: F=10.89, right side:12.34; P<0.05). Conclusion Compared with two other techniques, additional improvements can be obtained by using h-IMRT. h-IMRT plan is more appropriate for early breast cancer patients after breast-conserving surgery.