中华放射肿瘤学杂志
中華放射腫瘤學雜誌
중화방사종류학잡지
CHINESE JOURNAL OF RADIATION ONCOLOGY
2009年
1期
57-60
,共4页
胡银祥%卢冰%周华宁%甘家应%洪卫
鬍銀祥%盧冰%週華寧%甘傢應%洪衛
호은상%로빙%주화저%감가응%홍위
肺肿瘤/三维适形放射疗法%剂量体积直方图%靶区修改
肺腫瘤/三維適形放射療法%劑量體積直方圖%靶區脩改
폐종류/삼유괄형방사요법%제량체적직방도%파구수개
Lung neoplasms/three dimensional conformal radiotherapy%Dose-volume histo grams%Target volume modifing
目的 分析肺癌前、后程三维适形计划中正常肺剂最体积直方图变化及其与两程计划合成结果比较,探讨正常肺剂量体积直方图变化规律及放疗中靶区修改的可行性.方法 选择21例接受三维适形后程加速超分割放疗的非小细胞肺癌病例,设定首程(P1)、后程(P2)三维适形计划的处方剂量均为70 Gy,V20≤35%.将P.按常规分割照射40 Gy后,重新定位并修改靶区后设计P2,加速超分割照射30 Gy.将P1靶区、射野和剂量(MU)等物理参数导入P2CT定位图像中,与之合成得到70 Gy合成计划(Pc);计算首程和后程总肺体积、靶体积(GTV、PTV),计算首程、后程和合成计划中MLD、V5、V10、V20、V30.分析3种计划中各项指标变化规律,并单因素相关分析MLD和V20.结果 前、后两程计划总肺体积无明显变化(t=0.19,P=0.850),后程GTV、PTV较首程明显缩小(t=2.88,P=0.009;t=4.01,P=0.001).全组P2、P1的正常肺MLD分别为16.5、17.8 Gy(t=2.60,P=0.017)、V30显著降低(t=2.19,P=0.041);但V5、V10、V20相似.Pc较P1的肺MLD、V5、V10、V20、V30均相似.Pc较P2的肺MLD、V5、V10、V20、V30均明显增加.分层分析PTV缩小的14例患者P2、P1的V30、MLD显著降低(t=3.00,P=0.010;t=2.38,P=0.033),其中7例后程按首程射野数和相似入射角设计计划时V10、V30显著减小(t=2.76,P=0.033;t=3.60,P:0.011);Pc与P1比较各项指标相似,与P2比较明显增高.7例相差1～2射野和不同入射角的P1、P2和Pc之间各项指标相似.PTV不变或增大的7例P1和P2间各项指标也相似.PTV增大或缩小显著影响MLD和V20(r=-0.62,P=0.03;r=0.48,P=0.029).结论 非小细胞肺癌在三维适形后程加速超分割放疗过程中肿瘤明显缩小时,修改靶区及计划可降低正常肺高剂量体积,如按相同射野方向时可能缩小正常肺低剂量体积.后程计划设计物理参数应与首程相似,融合计划评估全程计划正常肺剂量体积直方图比较合理.
目的 分析肺癌前、後程三維適形計劃中正常肺劑最體積直方圖變化及其與兩程計劃閤成結果比較,探討正常肺劑量體積直方圖變化規律及放療中靶區脩改的可行性.方法 選擇21例接受三維適形後程加速超分割放療的非小細胞肺癌病例,設定首程(P1)、後程(P2)三維適形計劃的處方劑量均為70 Gy,V20≤35%.將P.按常規分割照射40 Gy後,重新定位併脩改靶區後設計P2,加速超分割照射30 Gy.將P1靶區、射野和劑量(MU)等物理參數導入P2CT定位圖像中,與之閤成得到70 Gy閤成計劃(Pc);計算首程和後程總肺體積、靶體積(GTV、PTV),計算首程、後程和閤成計劃中MLD、V5、V10、V20、V30.分析3種計劃中各項指標變化規律,併單因素相關分析MLD和V20.結果 前、後兩程計劃總肺體積無明顯變化(t=0.19,P=0.850),後程GTV、PTV較首程明顯縮小(t=2.88,P=0.009;t=4.01,P=0.001).全組P2、P1的正常肺MLD分彆為16.5、17.8 Gy(t=2.60,P=0.017)、V30顯著降低(t=2.19,P=0.041);但V5、V10、V20相似.Pc較P1的肺MLD、V5、V10、V20、V30均相似.Pc較P2的肺MLD、V5、V10、V20、V30均明顯增加.分層分析PTV縮小的14例患者P2、P1的V30、MLD顯著降低(t=3.00,P=0.010;t=2.38,P=0.033),其中7例後程按首程射野數和相似入射角設計計劃時V10、V30顯著減小(t=2.76,P=0.033;t=3.60,P:0.011);Pc與P1比較各項指標相似,與P2比較明顯增高.7例相差1～2射野和不同入射角的P1、P2和Pc之間各項指標相似.PTV不變或增大的7例P1和P2間各項指標也相似.PTV增大或縮小顯著影響MLD和V20(r=-0.62,P=0.03;r=0.48,P=0.029).結論 非小細胞肺癌在三維適形後程加速超分割放療過程中腫瘤明顯縮小時,脩改靶區及計劃可降低正常肺高劑量體積,如按相同射野方嚮時可能縮小正常肺低劑量體積.後程計劃設計物理參數應與首程相似,融閤計劃評估全程計劃正常肺劑量體積直方圖比較閤理.
목적 분석폐암전、후정삼유괄형계화중정상폐제최체적직방도변화급기여량정계화합성결과비교,탐토정상폐제량체적직방도변화규률급방료중파구수개적가행성.방법 선택21례접수삼유괄형후정가속초분할방료적비소세포폐암병례,설정수정(P1)、후정(P2)삼유괄형계화적처방제량균위70 Gy,V20≤35%.장P.안상규분할조사40 Gy후,중신정위병수개파구후설계P2,가속초분할조사30 Gy.장P1파구、사야화제량(MU)등물리삼수도입P2CT정위도상중,여지합성득도70 Gy합성계화(Pc);계산수정화후정총폐체적、파체적(GTV、PTV),계산수정、후정화합성계화중MLD、V5、V10、V20、V30.분석3충계화중각항지표변화규률,병단인소상관분석MLD화V20.결과 전、후량정계화총폐체적무명현변화(t=0.19,P=0.850),후정GTV、PTV교수정명현축소(t=2.88,P=0.009;t=4.01,P=0.001).전조P2、P1적정상폐MLD분별위16.5、17.8 Gy(t=2.60,P=0.017)、V30현저강저(t=2.19,P=0.041);단V5、V10、V20상사.Pc교P1적폐MLD、V5、V10、V20、V30균상사.Pc교P2적폐MLD、V5、V10、V20、V30균명현증가.분층분석PTV축소적14례환자P2、P1적V30、MLD현저강저(t=3.00,P=0.010;t=2.38,P=0.033),기중7례후정안수정사야수화상사입사각설계계화시V10、V30현저감소(t=2.76,P=0.033;t=3.60,P:0.011);Pc여P1비교각항지표상사,여P2비교명현증고.7례상차1～2사야화불동입사각적P1、P2화Pc지간각항지표상사.PTV불변혹증대적7례P1화P2간각항지표야상사.PTV증대혹축소현저영향MLD화V20(r=-0.62,P=0.03;r=0.48,P=0.029).결론 비소세포폐암재삼유괄형후정가속초분할방료과정중종류명현축소시,수개파구급계화가강저정상폐고제량체적,여안상동사야방향시가능축소정상폐저제량체적.후정계화설계물리삼수응여수정상사,융합계화평고전정계화정상폐제량체적직방도비교합리.
Objective To analyze the normal lung dose-volume histogram(DVH) varieties in the former and later period(P1 and P2)of three dimensional conformal radiation therapy(3DCRT) plans and the compound (Pc) plan in non-small cell lung cancer(NSCLC),and to access the feasibility to modify the target volume during the treatment course.Methods Twenty-one NSCLC patients who had received accelerated hyper-frationation 3DCRT in P2 were included in the study.Both of the P1 and P2 plans were redesigned to a total dose of 70 Gy with V20 smaller than 35%.When the target volume was modified and P2 plan was rede signed using accelerated hyper-frationation 3DCRT of 30 Gy after P1 plan of 40 Gy,the Pc plan was compoun ded by transmitting the parameters(such as target volume,irradiation field and dose) of P1 plan into P2 plan. Total lung volume and target volumes(GTV,PTV) of P1 and P2 were evaluated.MLD,V5,V10,V20 and V30 of P1,P2 and Pc were calculated.Results The total lung volume in P1 and P2 plans was not significantly dif ferent(t = 0.19,P = 0.850).The volumes of GTV,PTV in P2 were obviously smaller than P1 (t = 2.88,P = 0.009 ; t = 4.01 ,P = 0.001) .When comparing P2 with P1 ,MLD were 16.5 Gy Vs 17.8 Gy (t = 2.60, DOI:10.3760/cma.j.issn.1004-4221.2009.01.057 P = 0.017),V30 was significantly decreased (t = 2.19,P = 0.041),but V5,V10 and V20 had no significant difference.Similar differences were found in MLD,V5 ,V10 ,V20 and V30 when comparing Po to P1.P2 plans had significantly smaller MLD,Vs,V10,V20 and V30 than Pc plans.Fourteen patients with decreased PTV were further analyzed.The V30 and MLD decreased significantly (t = 3.00,P = 0.0 I 0;t = 2.38,P = 0.033), but V5 ,V10,V20 had no difference when comparing P1 and P2 plans.Among these 14 patients,the V10 and V30 decreased significantly(t = 2.76,P = 0.033 ; t = 3.60,P = 0.011) when P2 plans were generated using the same field number and beam angles in P1 plans in 7 patients.The parameters were similar in P1and Pc plans,but increased significantly when comparing to P2.Various parameters were the same among P1,P2 and Pc plans when P2 plans were designed using 1-2 different fields and angles in the other 7 patients.The differ ences were not significant between P1 and P2 plans in 7 patients with the same or increased PTV.Expansion or contraction of PTV significantly influenced MLD and V2o (r =-0.62,P = 0.03 ; r = O.48,P = 0.029). Conclusions When the tumor regresses,the high dose volume of the lung decreases with modifying the tar get volume and replanning in the later period using accelerated hyper-frationation 3DCRT.The low dose vol ume of the lung may decrease if the field orientations are same throughout the treatment.It is rational to eval uate the normal lung DVH of the whole plan when the physical parameters of the later period plan are the same as the former one.
