两种减少呼吸运动方法在非小细胞肺癌放疗靶区勾画中的应用

Application of two methods of reducing breathing exercises in target delineations in the radiotherapy of lung cancer

目的探讨肺癌放疗靶区勾画中主动呼吸控制(active breathing control,ABC)技术配合四维CT、简易腹部加压(simple manual epigastric compression,SMEC)技术配合四维CT对肺活动度、肺部放疗体积的影响。方法 50例非小细胞肺癌患者随机分为主动呼吸组27例,腹部加压组23例,主动呼吸组行ABC技术扫描和自由呼吸扫描,腹部加压组行SMEC技术和自由呼吸扫描,重建扫描图像后进行靶区勾画。比较ABC技术与自由呼吸扫描,SMEC技术和自由呼吸扫描模式下肺肿瘤左右(right-left,RL)、头脚(superior-inferior,SI)、前后(anterior-posterior,AP)运动幅度,依据剂量体积直方图评价两种技术双肺V_5、V_(10)、V_(20)、V_(30)剂量体积及总剂量体积(V_总)。结果主动呼吸组ABC扫描下肺肿瘤SI运动幅度[(5.04±0.64)mm]低于自由呼吸扫描[(15.58±0.71)mm](P<0.05),RL、AP运动幅度与自由呼吸扫描比较差异无统计学意义(P>0.05);腹部加压组SMEC技术扫描下肺SI运动幅度[(5.18±1.12)mm]低于自由呼吸扫描[(16.14±2.21)mm](P<0.05),RL、AP运动幅度与自由呼吸扫描比较差异无统计学意义(P>0.05);主动呼吸组ABC扫描下双肺V_5、V_(10)、V_(20)、V_(30)[(52.74±4.78)%、(38.76±4.92)%、(23.71±4.03)%、(15.54±3.43)%]均低于自由呼吸扫描[(62.54±5.63)%、(45.58±5.84)%、(29.02±5.10)%、(19.18±4.61)%](P<0.05),V_总[(3 725.00±184.41)cm3]高于自由呼吸扫描[(3 125.00±219.92)cm3](P<0.05);腹部加压组SMEC扫描下双肺V_5、V_(10)、V_(20)、V_(30)、V_总[(61.47±4.93)%、(43.89±4.74)%、(27.38±3.97)%、(17.77±3.56)%、(3 475.00±214.12)cm3]均低于自由呼吸扫描[(62.54±5.61)%、(45.58±5.40)%、(29.00±5.11)%、(19.18±4.62)%、(3 567.00±235.31)cm3](P<0.05);ABC扫描时SI、AP运动幅度与SMEC技术扫描比较差异无统计学意义(P>0.05),RL运动幅度低于SMEC技术扫描(P<0.05);ABC扫描时V_5、V_(10)、V_(20)、V_(30)低于SMEC技术扫描,V总高于SMEC技术扫描(P<0.05)。结论 ABC、SMEC技术配合四维CT均可有效减小肺肿瘤SI方向的呼吸动度,ABC技术在肺癌放疗靶区勾画中缩小V_5、V_(10)、V_(20)剂量体积及增加V总上效果明显。

Objective To explore the influence of active breathing control （ABC） plus four-dimensional CT （4D-CT） and simple manual epigastric compression （SMEC） plus 4D-CT on the lung tumor motion and lung volume in target delineation in the radiotherapy of tung cancer. Methods Fifty patients with non-small cell lung cancer were randomly divided into ABC group receiving ABC plus 4D-CD （n=27） and SMEC group receiving SMEC plus 4D-CD （n=23）, The acquired images were reconstructed and transmitted into therapy planning system for volume delineation. The right-left （RL）, superior-inferior （SI） and anterior-posterior （AP） lung tumor motion amplitudes were compared between two groups, and the dose volumes of V5 , V10, V20 and V30 and total dose volumes were evaluated by histogram. Results In ABC group, lung tumor motion amplitude of SI was lower under ABC scanning （（5.04±0.64） mm） than that under free breathing scanning （（15.58±0.71） mm） （P〈0.05）, and there were no significant differences in RL and AP amplitudes between two methods （P〉0.05）. In SMEC group, SI amplitude was lower under SMEC scanning （（5.18±1.12） mm） than that under free breathing scanning （（16.14±2.21） mm） （P〈0.05）, and there were no significant differences in RL and AP amplitude between two methods （P〉0.05）. In ABC group, the dose volumes of V5, V10, V20 and V30 were significantly lower under ABC scanning （（52.74 ± 4.78）±, （38.76 ± 4.92）%, （23.71 ± 4.03 ）%, （15.54 ± 3.43）% ） than those under free breathing scanning （ （ 62.54 ± 5.63） %, （45.58 ± 5.84） %, （ 29.02 ± 5.10） %, （ 19. 1 8 ± 4.6 ] ） %） （P〈0.05）, and the total dose volume was significantly higher under ABC scanning （3 725.00± 184.41） cm3） than that under free breething seanning （3 125.00±219.92） cm3） （P〈0.05）. In SMEC group, the dose volumes of V5, Vlo, V2oand V3o and the total dose volume were significantly lower under SMEC scanning （（61.47±4.93） %, （43.89±4.74） %, （27.38±3.97）%, （17.77±3. 56）%, （3 475.00±214.12） cm3） than those under free breathing scanning （（62.54± 5.61）%, （45.58±5.40）%, （29.00±5.11）%, （19. 18±4.62）%, （3 567.00±235.31） cm3） （P〈0.05）. There wasa significant difference in RL amplitude and there were no significant differences in SI and AP amplitudes between two scanning ways （P〉0.05）. The dose volumes of Vs , Vlo, V20 and V30 were significantly lower and the total dose volume was significantly higher under ABC scanning than those SMEC scanning （P〈0.05）. Conclusion Both ABC and SMEC plus 4D-CT can effectively reduce SI amplitude of lung tumor motion. ABC technique can effectively reduce the dose volumes of V5, V10 and V20 and increase the total dose volume in target delineation in the radiotherapy of lung cancer.