不同能量容积旋转调强技术在直肠癌术前放疗中的剂量学差异

发布时间：2018-04-28 16:14

本文选题：直肠癌 + 术前放疗　；参考：《中国老年学杂志》2017年04期

【摘要】：目的比较不同能量容积旋转调强技术(VMAT)在直肠癌术前放疗中的剂量学差异。方法选取18例直肠癌术前患者,在Eclipse10.0计划系统上分别进行6 MV和10 MV单弧VMAT计划设计。计划靶区(PTV)处方剂量为50 Gy/25次,2 Gy/次。在95%体积的PTV达到处方剂量前提下,比较两种计划的剂量体积直方图(DVH)、靶区和危及器官剂量、适形度指数(CI)、均匀性指数(HI)、正常组织低剂量体积(B-P)、机器跳数(MU)及治疗时间(TT)。结果 10 MV PTV的Dmean、V95 Gy、V105 Gy、HI均优于6 MV(P0.05),其CI二者相近差异无统计学意义(P0.05)。10 MV的小肠(Dmean、D5%、V40 Gy)、膀胱(D5%)低于6 MV(P0.05),而双侧股骨头组间无统计学差异(P0.05)。相对于10MV来说,BP的V5 Gy略高于6 MV,V10 Gy、V15 Gy、V20 Gy较6 MV低(P0.05),其V30 Gy二者间相似(P0.05)。10 MV的MU(427±53)和TT(72±6)s分别较6 MV的MU(365±21)和TT(67±3)s增加了17%、7%(P0.05)。结论在单弧VMAT治疗计划中,10 MV较6 MV提供了更优的靶区剂量分布,且对小肠和膀胱的保护有一定优势,但其MU和治疗时间的略微增多及带来的辐射防护问题亦不容忽视。
[Abstract]:Objective to compare the dosimetric difference of different energy volume rotation intensity modulation technique (VMATT) in preoperative radiotherapy for rectal cancer. Methods 18 patients with rectal cancer before operation were selected to carry out 6 MV and 10 MV single arc VMAT planning design on Eclipse10.0 planning system. The planned dose of PTV was 50 Gy/25 / 2 Gy/. Under the condition that 95% volume of PTV reached the prescribed dose, the dose of volume histogram, target area and organ dose, conformability index, homogeneity index, normal tissue low dose volume PTV, machine hopping time and therapeutic time were compared between the two plans. Results the Dmean V95 Gy V105 Gy HI of 10 MV PTV was better than that of 6 MV P0.05G. There was no significant difference in CI between the two groups. The Dmean D5V of 10 MV PTV was lower than that of 6 MV P0.05, and there was no significant difference between bilateral femoral head groups (P0.05). Compared with 10MV, the V 5 Gy of BP was slightly higher than that of 6 MV 10 Gy 15 Gy / V 20 Gy was lower than that of 6 MV P 0.05, and the MU(427 卤53 and TT(72 卤6 Ms of V30 Gy were similar to that of MU(365 卤21 and TT(67 卤3 s of 6 MV, respectively. Conclusion the dose distribution of 10 MV in single arc VMAT is better than that in 6 MV, and it has some advantages in protecting small intestine and bladder. However, the increase of MU and treatment time and the radiation protection can not be ignored.
【作者单位】：汕头大学医学院附属肿瘤医院放疗科;
【基金】：汕头大学医学院临床科研提升计划资助(201424)
【分类号】：R735.37;R730.55

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