Webb S
Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Trust, Sutton, Surrey, UK.
Phys Med Biol. 1999 Jul;44(7):1639-54. doi: 10.1088/0031-9155/44/7/305.
In this paper it is proposed that intensity-modulated radiotherapy (IMRT) could be delivered optimally by a short-length linac mounted on a robotic arm. The robot would allow the linac to 'plant' narrow pencils of photon radiation with any orientation (excluding zones within which the linac and couch might collide) relative to the planning target volume (PTV). The treatment is specified by the trajectory of the robot and by the number of monitor units (MUs) delivered at each robotic orientation. An inverse-planning method to determine the optimum robotic trajectory is presented. It is shown that for complex PTVs, specifically those with concavities in their outline, the conformality of the treatment is improved by the use of a complex trajectory in comparison with a less complex constrained trajectory and this improvement is quantified. It is concluded that robotic linac delivery would lead to a great flexibility in those IMRT treatments requiring very complicated dose distributions with complex 3D shapes. However, even using very fast computers, the goal of determining whether robotic linac delivery is the ultimate IMRT cannot be conclusively reached at present.
本文提出，安装在机械臂上的短长度直线加速器可以实现强度调制放射治疗（IMRT）的最佳递送。该机器人将允许直线加速器相对于计划靶区（PTV）以任何方向（不包括直线加速器和治疗床可能碰撞的区域）“植入”窄束光子辐射。治疗由机器人的轨迹和在每个机器人方向上递送的监测单位（MU）数量指定。提出了一种确定最佳机器人轨迹的逆向计划方法。结果表明，对于复杂的PTV，特别是那些轮廓有凹面的PTV，与不太复杂的受限轨迹相比，使用复杂轨迹可改善治疗的适形性，并对这种改善进行了量化。得出的结论是，在那些需要非常复杂的三维形状剂量分布的IMRT治疗中，机器人直线加速器递送将带来极大的灵活性。然而，即使使用非常快的计算机，目前也无法最终确定机器人直线加速器递送是否是终极的IMRT。
