The New Direction Research Of Optimization For Intensity Modulated Radiotherapy Plan

Intensity modulated Radiotherapy (IMRT) can make sure the target volume get theprescribe dose, as while the organs at risk (OAR) get a better dose sparing, thisadvantage become much more obvious when the target volume and the OARs get closerto each other[1,2]. At the early stage of IMRT technology, the objective of IMRToptimize process is to get a balance between the dose distribution of target volume andthe dose spare of OARs by invert IMRT optimize algorithm, and then generate atreatment plan which is accepted by the physicians[3,4].Though IMRT technology haspassed more than two decades from its beginning, the process of a IMRT plan is alsotime consuming and complex optimizing progress[1],a high quality IMRT plan is highlydepend on the planner’s experience and the optimizing dose standards which were gotfrom conventional three deviational plan. The most parameters of the IMRT plan aresettled manually, these parameters contain both machine parameters and objectivefunctions which were used during the invert optimize progress. As a result, when thenumber of optimized parameters becomes larger, the relationships of target volume andOARs become much more complex, the IMRT plan will become much more timeconsuming and complex. Because of reasons mentioned above, if we develop a methodwhich can put planners’ experience in it or set the optimize parameters automated, thenwe can decrease human dependence of the plan quality and time consuming, as meanwhile increase the efficiency of plan making and plan quality.In this study, first, we will talk about some optimize alogrithms which appearedthese years, these algorithms contain studies of optimizing machine parameters andoptimizing objective functions of target volume and OARs. Second I will do someresearch studies of these fields by myself. My own research contains two fellow aspects:the first aspect, I will generate some IMRT plans by Beam angle optimization （BAO）algorithm which is equipped in Varian Eclipse treatment system in some cervical cancercases, and in the same cases, I will generate the conventional9equal spaced fieldsIMRT plan, and then compare the two group IMRT plans dose distributions to discussthe feasibility of using BAO algorithm in cervical cancer case IMRT plans; the secondaspect，during my visit in duke university medical center, we cooperate with them,putthe OARs predict model which was first created for prostate cancer IMRT plans to Head and Neck cancer cases, comparing the predict OARs DVH with IMRT plans whichwere already used in clinical,and convert the predict OARs DVH into objectivefunctions which will be optimized in IMRT plans VMAT plans to discuss the useful ofPredict model in IMRT plans and VMAT plans. At last, summarize all my researchstudies; find the advantages and disadvantages in them to find a better solution in IMRTplan designing progress. Finally, we can get a better IMRT plan with little timeconsuming, higher efficiency and higher quality consistent.