The Application Of KV CBCT Based Deformable Image Registration Of Adaptive Planning For Patients With Cancer In Lung

ObjectiveTo compare and analyse the difference of organ contour using planning CT and KVCBCT deformable image registration （DIR） and rigid image registration. the planningradiotherapy was compared of KV CBCT deformable image registration （DIR） ofadaptive planning and static planning for patients with cancer in lung, and evaluate theircharacters.Methods and methodOne set CT image and ten sets of KV CBCT i-mage of one patient were choose andtotal five patients. Organ contour were automatic outlined to using deformable planningCT and KV CBCT image reg-istration. To compare the organ contours different ofdeformable registration and rigid registration. Five patients with mass in lung participatedin the study. Two sets image were acquired every three days and were concatenated to oneset.Ten sets CBCT image and planning CT image were transferred a commercialdeformable image registration(DIR) software. The planning CT was deformed to each setCBCT and the contours delineated for planning purposes were propagated. Transfer ofeach deformed planning CT back into the treatment planning system (TPS) enablere-calculation of actual dose distribution. Ten times CBCT planning of every patient wereadded to acquire a total dose accumulation planning(DA plan),comparison of dosedistribution and dose-volume histogram (DVH) in CT plan and DA plan for fractionationdose and accumulation dose of left lung, right lung, total lung, PTV and spinal-cord.Resultsthe dice similarity coefficient of deformation registration and rigid registration were statistical(T=3.888,4.405,3.879,4.826,2.041; P=0.000,0.000,0.000,0.000,0.047,),the meanDSC of deformable registration is higher than rigid registration(0.9%，4%，1.7%，3.4%，1.6%),the DSC of body is the highest than left and right lung, heart, spinal(10.9%，9.4%，22%，30.9%). The accumulation dose of PTV in DA plan （69.6±1.06、41.12±17.45、55±21.18）Gy, CT plan（70.45±0.78、58.49±4.31、66.27±1.63）Gy，DA plan <CT plan（z=－2.023，p=0.043）；left, right, total lung V5、V10、V20、V30、V50,DAplan<CTplan,p（0.043、0.043、0.043、0.043、0.043；0.042、0.043、0.043、1、1；0.043、0.043、0.225、0.042、0.042）；spinal-cord accumulation max dose DA plan(28.6±8.1Gy)<CT plan(39.7±2.91Gy),（Z=-2.023，p=0.043）；left lung, right lung, and total lung accumulationmean dose, DA plan（26.72±5.22、35.5±0.97、14.1±0.90）Gy<CT plan（31±4.94、46.5±1.71、16.2±1.45）Gy，（z=-2.032、-2.023、-2.023，p=0.042、0.043、0.043）。ConclusionRR is at a competitive disadvantage in terms of organ contour outline. the body,leftand right lung that are used DR have advantage over the heart and spinal. And KV CBCTbased deformable image registration of adaptive planning reduce the dose of lung tissueand spinal-cord, and enhance the dose of PTV, This provides a tool for exploring adaptiveradiotherapy strategies.