TA23-QA Process of Fractionated Stereotactic Radiotherapy (FSR)
Ching-Chong Jack Yang, PhD
Radiation Oncology Dept.
Monmouth Medical Center
300 2nd Ave
Long Branch, NJ 07740
Performing LINAC based Radiosurgery with invasive fixation device has been a very standard procedure and has taken advantages of the high localization accuracy. However, for tumors that are more sensitive to the fractionation treatment scheme, then the invasive immobilization lost its clinical usage. In order to acquire both high treatment precision and sharp dose gradient from Radiosurgery procedures, Fractionated Stereotactic Radiotherapy (FSR) provides another alternative methodology. QA of the FSR procedure remains similar to the single fraction treatment delivery, checking laser and patient repositioning accuracy from the calculated isocenter coordinates are necessary before each treatment delivery. Vendors or in-house developed tools or devices can also help to identify the patient treatment location for achieving high treatment precision. QA of FSR relies on careful alignment of the fiducial markers (either internal or external), laser system adjustment and calibration (table mounted system), isocenter verification, and treatment delivery verification. Another important item for FSR QA is the collision test, which not only verified in planning system, but also in the treatment delivery phase since arc therapy with couch angles is always critical in QA verification.
TA23-分次立体定向放射治疗（FSR）的质量保证
Ching-Chong Jack Yang, PhD
Radiation Oncology Dept.
Monmouth Medical Center
300 2nd Ave
Long Branch, NJ 07740
使用有创固定设备进行基于加速器的立体定向放射外科已经成为立体定向放射外科中的一种标准技术，并且它充分利用了立体定向定位的高度准确性。但是，对于对治疗分次方案敏感的肿瘤，有创固定已经失去了其临床应用价值。为了同时获得立体定向放射外科高治疗精度和陡剂量梯度的优点，使用分次立体定向放射治疗（FSR）便成了很好的选择。分次立体定向放射治疗（FSR）的质量保证与单分次立体定向放射外科的质量保证过程类似，在每次治疗前需要检查激光灯，通过计算的等中心坐标确定病人重复定位的准确性。同时也可以使用商业销售或自己开发的工具或设备来识别病人的治疗位置，从而保证高治疗精度。分次立体定向放射治疗（FSR）的质量保证主要包括认真对准（内或外）标记点、激光系统的调整和校准（放在治疗床上的激光系统）、等中心的验证和治疗实施的验证。分次立体定向放射治疗（FSR）质量保证另一个非常重要的方面是防碰撞测试，它不但要在计划系统中验证，也要在治疗实施过程中验证，因为质量保证验证中验证转床的弧形治疗非常关键。