Kent Michael S, Gordon Ira K, Benavides Ines, Primas Paul, Young Jacque
Department of Surgical and Radiological Sciences and the Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616, USA.
Vet Radiol Ultrasound. 2009 Sep-Oct;50(5):550-4. doi: 10.1111/j.1740-8261.2009.01583.x.
The positioning accuracy and precision of a head and neck immobilization device for radiation therapy of tumors in the canine skull was evaluated. Nineteen dogs with a spontaneous tumor of the head were enrolled including 12 with an intracranial mass and seven with an intranasal or maxillary tumor. Three hundred thirty-three pairs of orthogonal digital portal radiographs were analyzed to assess patient displacement in the cranial-caudal, lateral, and dorso-ventral directions. The mean systematic displacement was 0.8, 1, and 0.9 mm. The mean random displacement was 1.9, 1.6, and 1.5 mm. These values resulted in an overall displacement of 2.1 mm in the cranial-caudal direction, 1.8mm in the lateral direction, and 1.7 mm in the dorsal-ventral direction. The mean displacement value of the three dimensional (3D) vector was 2.4 mm with a standard deviation of 2.1. Ninety-five percent of all vectors were < 6.4 mm. This study quantifies the precision and accuracy of this particular positioning device. Knowing the limitations and setup variability of the system being used to set patients up for daily radiotherapy is paramount to planning and delivering appropriate radiation doses, especially as more complex treatment methods are used.
对用于犬类颅骨肿瘤放射治疗的头颈固定装置的定位准确性和精确性进行了评估。纳入了19只患有头部自发性肿瘤的犬，其中12只患有颅内肿块，7只患有鼻内或上颌肿瘤。分析了333对正交数字门静脉造影照片，以评估患者在头-尾、横向和背-腹方向上的位移。平均系统位移分别为0.8、1和0.9毫米。平均随机位移分别为1.9、1.6和1.5毫米。这些值导致在头-尾方向上的总位移为2.1毫米，在横向方向上为1.8毫米，在背-腹方向上为1.7毫米。三维（3D）向量的平均位移值为2.4毫米，标准差为2.1。所有向量的95%<6.4毫米。本研究量化了这种特定定位装置的精确性和准确性。了解用于为患者进行每日放射治疗设置的系统的局限性和设置变异性对于规划和给予适当的放射剂量至关重要，尤其是在使用更复杂的治疗方法时。
