对比分析乳腺癌保乳术后常规放疗、三维适形放疗、直接子野优化调强适形放疗靶区剂量分布及危及器官受照体积的效果差异

Comparative Analysis of Conventional Radiotherapy, Three-dimensional Conformal Radiotherapy, Direct Subfield Optimized Intensity-modulated Conformal Radiotherapy Target Area Dose Distribution and the Effect Difference of Exposure Volume of Organs at Risk a

目的分析对比乳腺癌保乳术后常规放疗(2D-RT)、三维适形(3D-CRT)放疗、直接子野优化调强适形(DMPOIMRT)放疗靶区剂量分布及危及器官受照体积的效果差异。方法便利选取2017年11月—2019年5月于该院进行乳腺癌保乳术的患者33例,所有患者均需设计2D-RT、3D-CRT、DMPO-IMRT3种照射技术治疗方案,95%靶区体积符合所有治疗方案处方剂量(50 Gy/2 Gy/25次),对比3种方案靶区受量、相关正常器官受量差异、剂量分布。结果 DMPO-IMRT适形度指数(CI)(0.72±0.06)明显高于2D-RT(0.60±0.06)、3D-CRT(0.64±0.07),DMPO-IMRT的均匀性指数(HI)(1.11±0.03)明显低于2D-RT(1.15±0.04),差异有统计学意义(P<0.05),3D-CRT的CI略高于2D-RT,DMPOIMRT的HI略低于3D-CRT,3D-CRT的HI低于2D-RT,但组间差异无统计学意义(P>0.05),3D-CRT各剂量区的患侧肺、对侧乳腺、心脏受照体积小于2D-RT,DMPO-IMRT患侧肺V30、V20受照体积小于2D-RT,患侧肺V10、V5、对侧乳腺、心脏大于2D-RT,而DMPO-IMRT患侧肺V30小于3D-CRT,患侧肺V20、V10、V5、对侧乳腺、心脏大于3D-CRT。结论乳腺癌保乳术后进行3D-CRT、DMPO-IMRT,能明显改善靶区适形度与均匀性,且3D-CRT可缩小各剂量区危及器官受照体积,DMPO-IMRT可缩小高剂量患侧肺受照体积,同时可增大低剂量患侧肺以及对侧乳腺、心脏受照体积。

Objective To analyze and compare the dose distribution and risk of conventional radiotherapy(2 D-RT), threedimensional conformal(3 D-CRT) radiotherapy, and direct subfield optimization intensity-modulated conformal(DMPOIMRT) radiotherapy after breast-conserving breast cancer surgery and the effect of organ exposure volume is different.Methods Thirty-three patients who underwent breast-conserving surgery for breast cancer in our hospital from November2017 to May 2019 were convenielnty selected. All patients were required to design three radiation technology treatment plans: 2 D-RT, 3 D-CRT, and DMPO-IMRT, 95% volume of the target area conforms to the prescribed doses of all treatment plans(50 Gy/2 Gy/25 times), and the target area receiving amount, the relevant normal organ receiving amount difference and the dose distribution of the three plans were compared. Results The conformity index(CI) of DMPO-IMRT(0.72±0.06)was significantly higher than that of 2 D-RT(0.60±0.06), 3 D-CRT(0.64±0.07), and the uniformity index(HI) of DMPOIMRT(1.11±0.03) was significantly lower than 2 D-RT(1.15±0.04), the difference was statistically significant(P<0.05), the CI of 3 D-CRT was slightly higher than that of 2 D-RT, the HI of DMPO-IMRT was slightly lower than that of 3 D-CRT, and the HI of 3 D-CRT was lower than 2 D-RT, but the difference between the groups was not statistically significant(P﹥0.05),the affected lung, contralateral breast, and heart in each dose area of 3 D-CRT were less than 2 D-RT, and the affected lung of DMPO-IMRT was V30, the irradiated volume of V20 was smaller than 2 D-RT, the affected lung V10, V5, contralateral breast, and heart were larger than 2 D-RT, while the affected lung V30 of DMPO-IMRT was smaller than 3 D-CRT, and the affected lung V20, V10, V5, contralateral breast and heart were larger than 3 D-CRT. Conclusion 3 D-CRT and DMPO-IMRT after breast-conserving breast cancer can significantly improve the conformity and uniformity of the target area, and 3 D-CRT can reduce the exposure volume of organs at risk in each dose area, and DMPO-IMRT can reduce the high dose irradiated volume of the affected lung can also increase the irradiated volume of the low-dose affected lung and the contralateral breast and heart.