O'Brien P F, Gillies B A, Schwartz M, Young C, Davey P
Toronto-Bayview Regional Cancer Centre, Sunnybrook Health Science Centre, Ontario, Canada.
Med Phys. 1991 May-Jun;18(3):519-21. doi: 10.1118/1.596656.
One of the major drawbacks to doing stereotactic radiosurgery with a linear accelerator is the long time required to deliver the target dose. Single fractions of 25 Gy delivered at the isocenter and at depth in the skull may require beam times in excess of 15 min for a typical linear accelerator with a maximum dose rate of 250 cGy/min in tissue. In an effort to decrease the treatment time for this technique, the flattening filter has been removed from an AECL Therac-6 linear accelerator and the characteristics of the resulting beam have been measured. Flatness is acceptable for the field sizes used with this technique and the dose rate is increased by a factor of 2.75.
使用直线加速器进行立体定向放射外科手术的一个主要缺点是输送目标剂量所需的时间较长。对于在等中心和颅骨深处单次给予25 Gy剂量的情况，对于组织中最大剂量率为250 cGy/分钟的典型直线加速器，可能需要超过15分钟的束流时间。为了减少该技术的治疗时间，已从AECL Therac - 6直线加速器上移除了均整滤过器，并对由此产生的射束特性进行了测量。对于该技术所使用的射野大小，平整度是可接受的，并且剂量率提高了2.75倍。
