{"title":"计划VMAT对颅脊髓照射的稳健性","authors":"Jian Xu, Qiang Wang, Keqiang Wang, Huipeng Meng, Hua-jiang Dong","doi":"10.3760/CMA.J.ISSN.1673-4181.2019.01.009","DOIUrl":null,"url":null,"abstract":"Objective \nTo compare the dosimetric characteristics of the methods of volumetric modulated arc therapy (VMAT) for craniospinal irradiation, and to compare their robustness to the field placement error. \n \n \nMethods \nSix patients receiving craniospinal irradiation were included. VMAT plans of each patient were optimized with overlap method and gradient-optimization method respectively using Pinnacle 9.8 VMAT treatment planning system. The length of the overlap region was set as 3 and 9 cm, respectively. Then the dose distributions under different VMAT programs were measured. Moreover, a 3 mm placement error was introduced, and the dose cold spot in the field junction region obtained by each plan was compared for robustness analysis. \n \n \nResults \nUnder different overlapping lengths, the overlap method and the gradient optimization method both can optimize the VMAT plan that meeting the clinical requirements. In the field junction region, the dose distribution obtained by the overlap method was more uniform, and the difference in the uniformity index was statistically significant. When introducing a 3 mm placement error, the gradient optimization method obtained the most robust VMAT plan at 9 cm overlap length, and the overlap method could not obtained stabilized robust plan. \n \n \nConclusions \nFor the optimization of craniospinal irradiation VMAT plan, the commonly used overlap method can obtain a better dose distribution, but it can't improve robustness by increasing overlap length. However, using the gradient optimization method, the dose homogeneity in the field junction region is not good as the overlap method, but the plan robustness can be improved by increasing the overlap length. \n \n \nKey words: \nCraniospinal irradiation; Volumetric modulated arc therapy; Robustness; Overlap gradient-optimization","PeriodicalId":61751,"journal":{"name":"国际生物医学工程杂志","volume":"42 1","pages":"50-54"},"PeriodicalIF":0.0000,"publicationDate":"2019-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Plan robustness of craniospinal irradiation with VMAT\",\"authors\":\"Jian Xu, Qiang Wang, Keqiang Wang, Huipeng Meng, Hua-jiang Dong\",\"doi\":\"10.3760/CMA.J.ISSN.1673-4181.2019.01.009\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Objective \\nTo compare the dosimetric characteristics of the methods of volumetric modulated arc therapy (VMAT) for craniospinal irradiation, and to compare their robustness to the field placement error. \\n \\n \\nMethods \\nSix patients receiving craniospinal irradiation were included. VMAT plans of each patient were optimized with overlap method and gradient-optimization method respectively using Pinnacle 9.8 VMAT treatment planning system. The length of the overlap region was set as 3 and 9 cm, respectively. Then the dose distributions under different VMAT programs were measured. Moreover, a 3 mm placement error was introduced, and the dose cold spot in the field junction region obtained by each plan was compared for robustness analysis. \\n \\n \\nResults \\nUnder different overlapping lengths, the overlap method and the gradient optimization method both can optimize the VMAT plan that meeting the clinical requirements. In the field junction region, the dose distribution obtained by the overlap method was more uniform, and the difference in the uniformity index was statistically significant. When introducing a 3 mm placement error, the gradient optimization method obtained the most robust VMAT plan at 9 cm overlap length, and the overlap method could not obtained stabilized robust plan. \\n \\n \\nConclusions \\nFor the optimization of craniospinal irradiation VMAT plan, the commonly used overlap method can obtain a better dose distribution, but it can't improve robustness by increasing overlap length. However, using the gradient optimization method, the dose homogeneity in the field junction region is not good as the overlap method, but the plan robustness can be improved by increasing the overlap length. \\n \\n \\nKey words: \\nCraniospinal irradiation; Volumetric modulated arc therapy; Robustness; Overlap gradient-optimization\",\"PeriodicalId\":61751,\"journal\":{\"name\":\"国际生物医学工程杂志\",\"volume\":\"42 1\",\"pages\":\"50-54\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-02-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"国际生物医学工程杂志\",\"FirstCategoryId\":\"1087\",\"ListUrlMain\":\"https://doi.org/10.3760/CMA.J.ISSN.1673-4181.2019.01.009\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"国际生物医学工程杂志","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.3760/CMA.J.ISSN.1673-4181.2019.01.009","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Plan robustness of craniospinal irradiation with VMAT
Objective
To compare the dosimetric characteristics of the methods of volumetric modulated arc therapy (VMAT) for craniospinal irradiation, and to compare their robustness to the field placement error.
Methods
Six patients receiving craniospinal irradiation were included. VMAT plans of each patient were optimized with overlap method and gradient-optimization method respectively using Pinnacle 9.8 VMAT treatment planning system. The length of the overlap region was set as 3 and 9 cm, respectively. Then the dose distributions under different VMAT programs were measured. Moreover, a 3 mm placement error was introduced, and the dose cold spot in the field junction region obtained by each plan was compared for robustness analysis.
Results
Under different overlapping lengths, the overlap method and the gradient optimization method both can optimize the VMAT plan that meeting the clinical requirements. In the field junction region, the dose distribution obtained by the overlap method was more uniform, and the difference in the uniformity index was statistically significant. When introducing a 3 mm placement error, the gradient optimization method obtained the most robust VMAT plan at 9 cm overlap length, and the overlap method could not obtained stabilized robust plan.
Conclusions
For the optimization of craniospinal irradiation VMAT plan, the commonly used overlap method can obtain a better dose distribution, but it can't improve robustness by increasing overlap length. However, using the gradient optimization method, the dose homogeneity in the field junction region is not good as the overlap method, but the plan robustness can be improved by increasing the overlap length.
Key words:
Craniospinal irradiation; Volumetric modulated arc therapy; Robustness; Overlap gradient-optimization