各向异性分析算法和光子笔形束卷积算法在食管癌放射治疗中的剂量学比较  

Dosimetric comparison of AAA and PBC dose calculation algorithm for intensity modulated radiation therapy in esophageal carcinoma

作　　者：花威[1] 李军[1] 陈婷婷[1] 张西志[1] 陈雪梅[1] 

机构地区：[1]苏北人民医院放疗科,江苏扬州225001

出　　处：《生物医学工程与临床》2013年第4期359-362,共4页Biomedical Engineering and Clinical Medicine

摘　　要：目的比较食管癌调强放射治疗各向异性分析算法（AAA）与光子笔形束卷积（PBC）算法的剂量学差异。方法选取9例食管癌患者,其中男性6例,女性3例;年龄54-68岁,平均年龄61岁。用瓦里安Eclipse 8.6治疗计划系统设计5野均分逆向调强计划,分别用AAA和PBC算法模型计算并利用COMPASS进行剂量验证。利用剂量体积直方图比较靶区、肺、心脏和脊髓照射剂量和体积。数据应用SPSS15.0进行配对t检验分析。结果大体肿瘤区（GTV）的均匀性指数（HI）、适合度指数（CI）、Dmean及计划靶区（PTV）的HI,AAA结果均优于PBC算法,差异均有统计学意义（P〈0.05）。AAA双肺各指标差值为-0.02%～-1.87%,即低估了肺2%以内的受量。PBC算法双肺各指标差值为-3.95%～1.05%,低剂量区（V5～15）低估了肺4%以内的受量,高剂量区（V20～30）则稍高估。对于脊髓,AAA和PBC算法分别高估了1.57%、4.49%。两种算法都低估了心脏的受量,但AAA相对准确。结论食管癌放射治疗中采用AAA优于PBC算法。Objective To compare the dosimetric difference between anisotropic analytical algorithm（AAA） and pencil beam convolution（PBC） algorithm for intensity modulated radiation therapy（IMRT） plans in esophageal carcinoma.Methods Nine esophageal cancer cases were enrolled,included 6 males and 3 females,who were 54-68 years old with a mean age of 61.IMRT plan（five-fixed-field） was calculated with AAA and PBC,and generated by Varian Eclipse 8.6 treatment planning system.The COMPASS dose verification system was used to verify these plans.The target and organs at risk（OAR） were evaluated with dosevolume histograms（DVH）,and the Paired-Sample t test was taken by SPSS 15.0.Results AAA had more advantages in homogeneity index（HI）,conformity index（CI） and Dmeanof gross tumor volume（GTV）,and HI of planning target volume（PTV）,there were significant differences（P 0.05）.The double lung index difference of AAA was-0.02 % to-1.87 %,which indicated the underestimation of lungs within 2 %.The double lung index difference of AAA was-3.95 %-1.05 %,low dose region（V5-15） underestimated lung within 4 % by volume,and high dose region（V20-30） was slightly overestimated.Two algorithms overestimated spinal cord,the difference was 1.57 % for AAA and 4.49 % for PBC.Both of them underestimated the absorbed dose of heart,but AAA was relatively accurate.Conclusion It is demonstrated that esophageal carcinoma radiotherapy using AAA algorithm is superior to PBC algorithm.

关 键 词：各向异性分析算法 光子笔形束卷积算法 食管癌 调强放射治疗 剂量学 

分 类 号：R735.1[医药卫生—肿瘤]