高级检索

野中野正向调强与固定野逆向调强在全脑放疗中的剂量学差异

Dosimetry difference between field-in-field intensity modulated radiation therapy and fixed field inversely optimized intensity modulated radiation therapy in whole brain radiotherapy

    摘要
  • 摘要:
      目的  比较全脑放疗的野中野正向静态调强(FIF-IMRT)与固定野逆向优化调强(FFIO-IMRT)技术的剂量学差异。
      方法  选取需行全脑放疗患者20例，采用Pinnacle3 9.10治疗计划系统进行计划设计, 2种计划均用6 MV X射线, 处方剂量均为40 Gy, 2 Gy/次，共20次。FIF-IMRT计划选270 °、90 °为主野，适当调整准直器角度，使双眼球重叠，在每个主野方向手动添加1~2个子野降低高剂量。FFIO-IMRT计划7野均分调强，通过反复改变优化参数来达到临床要求的剂量分布。比较2种放疗计划的剂量学参数。
      结果  ① 靶区方面:与FFIO-IMRT计划相比, FIF-IMRT计划的计划靶区(PTV)的V105%、D50%升高, Dmin、Dmax、V95%、V110%、D2%、D98%降低，差异均有统计学意义(P < 0.05); FIF-IMRT计划的CI低于FFIO-IMRT, HI却高于FFIO-IMRT, 差异均有统计学意义(P < 0.05); FIF-IMRT计划子野数、机器跳数MU、治疗时间、计划设计时间均较FFIO-IMRT显著降低(P < 0.05)。②危及器官左右晶体、左右眼球、脊髓、左右视神经方面, FIF-IMRT计划低于FFIO-IMRT计划，晶体尤为明显，除左右视神经外，其他差异均有统计学意义(P < 0.05)。
      结论  ① 2种计划的靶区均达到临床剂量学要求。② FIF-IMRT计划在靶区的适形性上虽差于FFIO-IMRT计划，但在危及器官的保护方面远好于FFIO-IMRT计划。③由于FIF-IMRT计划的单次治疗时间显著减少，因此降低了器官运动带来的误差，同时减少了机器的损耗，提高了机器执行效率。④ FIF-IMRT计划设计简单易行，在基层医院也较容易实现。故全脑放疗推荐野中野正向静态调强的方式。

     

    Abstract:
      Objective  To compare dosimetry difference between field-in-field intensity modulated radiation therapy (FIF-IMRT) and fixed field inversely optimized intensity modulated radiation therapy (FFIO-IMRT) in whole brain radiotherapy.
      Methods  Totally 20 patients with whole brain radiotherapy were selected. The Pinnacle3 9.10 treatment planning system was used to design plan. 6 MV X-ray was used for both two plans, and the prescription dosage was 40 Gy, with 2 Gy per time for 20 times totally. FIF-IMRT plans to select 270 and 90 degrees as the main fields, adjust the collimator angle appropriately to make the eyes overlap, and manually add 1 or 2 sub-fields in each main field direction to reduce the high dose. FFIO-IMRT plans to equalize the intensity of 7 fields and achieve the clinical dose distribution by repeatedly changing the optimized parameters. The dosimetric parameters of two radiotherapy schemes were compared.
      Results  Compared with FFIO-IMRT, the V105% and D50% of the planned target area (PTV) in FIF-IMRT increased significantly, while Dmin, Dmax, V95%, V110%, D2%, D98% decreased significantly (P < 0.05). CI of FIF-IMRT was significantly lower than that of FFIO-IMRT, but HIV was significantly higher than that of FFIO-IMRT (P < 0.05). The number of planned subfields, machine hops MU, treatment time and planning design time of FIF-IMRT were significantly lower than those of FFIO-IMRT (P < 0.05). The FIF-IMRT plan was significantly lower than the FFIO-IMRT plan in terms of organ-threatening left and right crystals, right and left eyeballs, spinal cord and right optic nerves, especially in crystals. There were significant differences except for left and right optic nerves between two plans (P < 0.05).
      Conclusions  ① Both treatment plans could meet the requirements of clinical dosimetry. ② Although the CI of FIF-IMRT is worse than FFIO-IMRT, but FIF-IMRT is better in protection of organs. ③ Since the single treatment time of FIF-IMRT significantly shorten, the errors caused by organ movement are reduced, the loss of MLC is reduced, and the execution efficiency of the machine is improved. ④ The FIF-IMRT plan is simple designed and easy to implement in primary hospitals. Therefore, the FIF-IMRT is recommended for whole brain radiotherapy.

     

    • HTML全文
    • 参考文献(20)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回