摘要
目的:探讨鼻咽癌动态调强方式(Sliding window)和静态调强方式(Stepand shoot)2种调强方式的剂量学差异。方法:采用CADPLAN6.4.7(helios)治疗计划系统,对15例鼻咽癌需调强治疗的患者用Sliding window和Step and shoot2种调强方式4种强度水平(Intensity Level)进行剂量学差异的比较。按强度水平分为SW、SSL10、SSL7、SSL5组。对4组的剂量学评估参数:PTV最大剂量(PTVDmax)、PTV平均剂量(PTVDmean)、PTV最小剂量(PTVDmin)、剂量体积直方图(DVH)、适型指数(Conformity index,CI)、剂量不均匀性指数(Heterogene-ity Index,HI)、机器跳数(MU)、子野数目(Segment)等数据进行评价。结果:(1)SW组PTV Dmax与SSL10、SSL7、SSL5组间比较差异有统计学意义(P<0.05),而SSL10、SSL7、SSL5组比较差异无统计学意义(P>0.05),随着强度水平的降低,最大剂量增高;(2)SW组MU与SSL10、SSL7、SSL5组比较差异有统计学意义(P<0.01),而SSL10、SSL7、SSL5组间差异无统计学意义(P>0.05);(3)各组间Segment差异均有统计学意义(P<0.01);(4)各组间CI比较差异均无统计学意义(P>0.05);(5)各组间HI比较差异均无统计学意义(P>0.05)。结论:鼻咽癌不同调强方式和强度水平的治疗计划均能为临床提供较满意的剂量学分布,Sliding window方式略优于不同强度水平的Step and shoot方式,但MU和Segment较多。
Objective： To investigate the characteristics of sliding window and step and shoot dosimetry difference for nasopharynx cancer IMRT. Methods. Cadplan 6. 4. 7 （helios） TPS, for 15 nasopharynx cancer IMRT patients, used Sliding window and Step and shoot two techniques, compared with in the dosimetry difference. （DVH）, conformity index （CI）, heterogeneity index （HI）, MU, segment ,and data evaluation. Results： The differences of PTVDmax, in SW to SSL10,SSL7, SSL5 were significant （P 〈 0.05） ; While in SSL10,SSL7,SSL5 group （P 〉0.05） were not significant. To MU observation, SW group had signifisoncant differences with SSL10,SSL7, and SSL5 （P 〈0.01）. While SSL10, SSL7, SSL5 had not significant difference （P 〉0.05）. Segment in SW group had difference with SSL10 group, SSL7 group and SSL5 group （P 〈0.01）. CI in SW group and in SSL10 group, SSL7 group, SSL5 group had not significant difference （P 〉0.05）. HI in SW group and in SSL10 group, SSL7 group, SSL5 group had not significant difference （P 〉0.05）. OARs （spinal,brainstem,lens,optic nerve,parotid） Dmax were not significant （P 〉0.05）. Conclusions： The nasopharynx cancer IMRT plan to be able for clinical to provide the more satisfactory dosimetry distribution, but the different techniques has the difference in the dosimetry. Silding window need more MU and segment complete the treatment, but the uniformity is best. Reduces MU and Segments along with the intensity level are also less but PTVdmax to advance. OARs（spinal, brainstem, lens, optic nerve, parotid）
出处
《新疆医科大学学报》
CAS
2007年第4期393-395,共3页
Journal of Xinjiang Medical University
关键词
调强放射治疗
动态调强方式
静态调强方式
剂量学
计划比较
IMRT
sliding window
Dmax and CI, HI were not significant. step and shoot
dosimetry
plan comparison
