Sixel K E, Podgorsak E B, Souhami L
Department of Physics, McGill University, Montréal, Québec, Canada.
Med Phys. 1993 Jan-Feb;20(1):163-70. doi: 10.1118/1.597081.
A linac-based radiosurgical technique is reported which produces cylindrical isodose distributions covering cylindrical targets of arbitrary orientations within the patient's head. The technique uses rectangular collimators and 4 degrees of freedom: gantry and couch rotation, as defined by a previously known dynamic rotation technique, collimator rotation, and collimator length adjustment. The relationship between the four parameters is derived and because of its complexity, the cylindrical dynamic rotation technique is introduced as a pseudodynamic technique. For cylindrical targets, the cylindrical pseudodynamic technique is comparison to the standard spherical technique produces considerable dose savings to healthy tissue surrounding the target and gives a similar or better dose fall-off outside the target.
报道了一种基于直线加速器的放射外科技术，该技术可产生圆柱形等剂量分布，覆盖患者头部内任意方向的圆柱形靶区。该技术使用矩形准直器和4个自由度：机架和治疗床旋转（如先前已知的动态旋转技术所定义）、准直器旋转和准直器长度调整。推导了这四个参数之间的关系，由于其复杂性，将圆柱形动态旋转技术作为一种伪动态技术引入。对于圆柱形靶区，将圆柱形伪动态技术与标准球形技术进行比较，结果表明该技术可显著节省靶区周围健康组织的剂量，并在靶区外给出相似或更好的剂量下降。
