Gierga David P, Chen George T Y, Kung Jong H, Betke Margrit, Lombardi Jonathan, Willett Christopher G
Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA.
Int J Radiat Oncol Biol Phys. 2004 Apr 1;58(5):1584-95. doi: 10.1016/j.ijrobp.2003.09.077.
The treatment of moving targets with intensity-modulated radiotherapy may introduce errors in dose delivery. The motion of tumors in the abdomen was studied using quantitative fluoroscopic analysis, and the effect on dose delivery to the target was studied.
Fluoroscopy sessions for 7 patients with pancreas or liver tumors and fiducial clips were recorded, converted to digital format, and analyzed to quantify the characteristics of tumor motion. Intensity-modulated radiotherapy plans were generated for 3 patients (a total of five plans), and the dose-volume histograms for the target volume were compared between plans with and without tumor motion.
The average magnitude of the peak-to-peak motion for the 7 patients in the craniocaudal and AP directions was 7.4 mm and 3.8 mm, respectively. The clip motion varied widely, because the maximal clip excursions were about 47% greater than the average clip excursions for each patient. The inclusion of tumor motion did not lead to a significant degradation in the target dose-volume histogram for four of five treatment plans studied.
The amount of tumor motion for most patients in this study was not large but could, in some instances, significantly degrade the planned target dose-volume histogram. For some patients, therefore, motion mitigation or intervention during treatment may be necessary.
调强放射治疗移动靶区可能会在剂量传递方面引入误差。本研究使用定量荧光透视分析来研究腹部肿瘤的运动，并研究其对靶区剂量传递的影响。
记录了7例患有胰腺或肝脏肿瘤并植入基准夹的患者的荧光透视检查过程，将其转换为数字格式，并进行分析以量化肿瘤运动的特征。为3例患者生成了调强放射治疗计划（共5个计划），并比较了有和没有肿瘤运动情况下靶区体积的剂量体积直方图。
7例患者在头脚方向和前后方向上的峰峰值运动平均幅度分别为7.4毫米和3.8毫米。夹子的运动差异很大，因为每个患者夹子的最大偏移量比平均偏移量大约大47%。在所研究的5个治疗计划中，有4个计划纳入肿瘤运动并未导致靶区剂量体积直方图出现显著恶化。
本研究中大多数患者的肿瘤运动量不大，但在某些情况下可能会显著恶化计划的靶区剂量体积直方图。因此，对于某些患者，治疗期间可能需要减轻运动或进行干预。
