Kwa W, Tsang V, Fairey R N, Jackson S M, El-Khatib E, Harrison R W, Kristensen S
Department of Physics, University of British Columbia, Vancouver, Canada.
Int J Radiat Oncol Biol Phys. 1997 Feb 1;37(3):705-10. doi: 10.1016/s0360-3016(96)00543-3.
To illustrate some of the radiation treatment techniques with asymmetric collimators in one field dimension.
Treatment planning for various sites is done with an in-house developed treatment planning system. Dose distributions in the central plane are illustrated.
The use of asymmetric collimation, in addition to being a replacement for cerrobend and lead blocks, can facilitate treatment setup with boost fields and with half-beam asymmetric fields as in matching two adjacent fields, in avoiding nearby critical organ or tissue, and in tangential breast treatment. The use of asymmetric collimators would alter the dose distribution across the radiation field and should be accounted for during treatment planning. In conjunction with arc rotation or multiple asymmetric fields, two-dimensional conformal radiotherapy is possible.
The full potential of asymmetric collimation requires the use of a proper treatment planning algorithm. Some of the treatment techniques with asymmetric collimation in one field dimension are shown here.
阐述在一个射野维度上使用不对称准直器的一些放射治疗技术。
利用自行研发的治疗计划系统对不同部位进行治疗计划。展示中心平面的剂量分布。
使用不对称准直，除了可替代铈铜合金和铅挡块外，在设置加量野和半束不对称野（如匹配两个相邻射野）时有助于治疗摆位，能避免临近关键器官或组织，还可用于乳腺切线野治疗。使用不对称准直器会改变整个辐射野的剂量分布，在治疗计划过程中应予以考虑。结合弧形旋转或多个不对称野，可实现二维适形放疗。
不对称准直的全部潜能需要使用合适的治疗计划算法。本文展示了在一个射野维度上使用不对称准直的一些治疗技术。
