采用仿真头模及剂量计检验X刀治疗脑室肿瘤的剂量分布研究

Study On Dose Distribution of Radiosurgical Treatment of X Knife for Brain Tumour by TLD and Emulational Head Phantom

目的采用美国Kodak-omatXTL-2剂量胶片,LiF(Mg,Cu,P)CR-200ATLD和仿真人体头模,检验X刀放射治疗脑室肿瘤剂量分布的可行性。方法仿真头模以3cm厚做横向(水平面)切开,共切成四片,取其中二、三片(即A片和B片),每一层面关键器官上设置若干直径1cm,长0.5cm的测试孔,孔中放入TLD剂量计,每间隔10mm一个测点。测量采用临床常用的二种不同治疗照射方案,计算出各测试点的理论实验值及重建精度。结果TLD剂量计的测量结果在5%以内符合,剂量胶片的测量结果在3%以内符合,均能满足放射治疗的剂量学要求。结论可见采用LiF(Mg,Cu,P)CR-200ATLD计,Kodak-omatXTL-2剂量胶片及仿真人体头模检验X刀治疗脑室肿瘤的剂量分布准确、可靠。

Objective To investigate the feasibility of checking the dose distribution of radiosurgical treatment of X knife for brain tumour by LiF（Mg,Cu,P）CR-200A TLD and the tissue equivalent head phantom. Methods The tissue equivalent head phantom was cut into four slice, with taking of the second and the third slice being chosen to be used. Small holes （φ1 × 0.5 cm） were drilled at the interesting organs on each segment. The TLD（φ1×0.5 cm）were placed in the holes, The doses to each measuring position were calculated out. After the treatment plan was delivered the does to each TLD were measured by dosimeter. Measuring the dose distribution in phantom for head using TLD and film dosimeter is to verify the does for clinical practice. Results The relative errors for those TLD are within ± 5 %. The relative errors for those films are, within ±3 %. Conclusion The LiF（Mg, Cu, P）CR-200ATLD, film dosimeter are accurate and reliable in checking the dose distribution of radiosurgical treament of Jx-100x knife for brain tumour.