摘要
目的比较宫颈癌术后调强放疗(IMRT)计划中不同子野参数的选择对靶区适形度、剂量分布、危及器官受量及照射时间的影响,以制定最优的临床放疗计划。方法选取10例宫颈癌术后患者的IMRT计划,对其盆腔淋巴引流区及亚临床区(CTV)给予处方剂量(46 Gy/23次),并根据RTOG危及器官限量表对其危及器官(OAR)给予限定剂量,调整射野角度分别为210°、260°、310°、0°、50°、100°、150°。在Elekta XIO放疗计划系统(TPS)上对同一患者的IMRT计划分别调整最小子野面积(2、4、8 cm^2)和最小子野跳数(3、6、9 MU);用P1(2 cm^2,3MU),P2(4 cm^2,6MU),P3(8 cm^2,9MU)表示同一患者的3种不同的计划。比较各计划的靶区平均剂量、适形度指数、OAR受量以及平均治疗时间。结果所有患者各计划的靶区平均剂量和危及器官受量差异无统计学意义(P>0.05);靶区适形度指数、治疗总跳数及总子野数差异有统计学意义(P<0.05)。对于平均治疗时间,P2与P3比较无统计学差异(P>0.05),P1与P2、P3比较有统计学差异(P<0.05)。结论宫颈癌术后IMRT计划中最小子野面积及最小子野跳数不宜过大或过小,最小子野面积为4 cm^2、最小子野跳数为6 MU左右时的计划最优。
Objective To compare the influence of different beam parameters in IMRT（intensity modulated radiation therapy） plans for post-operative patients with cervical carcinomas on CI（conformity index） of the target volume,dose distribution,OAR（organ at risk） doses and irradiation time so as to formulate a optimal clinical radiotherapy plan.Methods The IMRI plans of 10 postoperative patients with cervical carcinomas were selected.Then,the prescription dose of 46 Gy in 23 fractions was administered to the pelvic lymphatic drainage region and CTV（clinical target volume）;the dose received by each OAR was limited to tolerance according to the RTOG（radiation therapy oncology group）.And the beam angle was adjusted as 210°,260°,310°,0°,50°,100° and 150° respectively.Additionally,every patient was given three different radiotherapy plans through adjustment of the MSA（minimum segment area） and minimum MU（monitor unit）：PI（2 cm^2,3 MU）,P2（4 cm^2,6 MU）,P3（8 cm^2,9MU）.Comparisons were made among three plans for each patient in the aspects of the average dose of target volumes,CI,OAR dose and average treatment time.Results There was no statistically significant difference between the average dose of the target volume and the limited dose of OAR（P〈0.05）.While,the statistically significant differences（P〈0.05） existed among CI,TNMU（total number of monitor unit） and the total NS（number of segment）.As for the average treatment time,there was no statistical significance（P〈0.05） between P2 and P3;while,statistically significant differences（P〈0.05） existed between P1 and P2 as well as P3.Conclusion This study indicated the optimal MSA（4 cm^2） and minimum MU（6 MU） in the IMRT plans for post-operative patients with cervical carcinomas.
出处
《中国医疗设备》
2015年第2期106-107,103,共3页
China Medical Devices
关键词
宫颈癌
调强放疗
最小子野面积
最小子野跳数
靶区适形度
危及器官受量
cervical carcinomas
intensity modulated radiation therapy
minimum segment area
minimum monitor unit
the conformity index of the target volume
dose of organ at risk
