非小细胞肺癌PET-CT定位同步加量调强放射治疗的剂量学研究

摘要

Objective To evaluate the dosimetric characteristics of PET-CT positioned SMART of NSCLC. Methods Target volumes of 10 cases of ⅢA and ⅢB NSCLC patients were sketched based on simple CT image and PET-CT image respec-tively. 3 radiotherapy plans were made for every patients:SMART on PET-CT image ( Group A ),SMART on CT image ( Group B ) and 3D-CRT on CT image ( Group C ). The dose distribution on the target volumes and surrounding normal tissues of the three groups were evaluated. Results The conformity indexes of GTV in Group A、B and C were respectively 0.72 ±0.03,0.72 ± 0. 02,0. 65 ± 0. 02. The conformity indexes of CTV were 0. 64 ± 0. 03 ,0. 64 ± 0. 02,0. 53 ± 0. 03. The homogeneity indexes of GTV were 1. 14 ± 0. 02,1. 15 ± 0. 02,1. 12 ± 0. 02. There were statistical differences between Group A and C, Group B and C ( P < 0. 05 ). There was no statistical difference between Group A and B ( P > 0. 05 ). The V5 of normal lung tissue in Group A,, B and C were respectively 53. 41 ±4. 90,56. 09 ±4. 61,55. 87 ±4. 27. The V10 were 33. 56 ±4. 02,35. 95 ± 3. 35 ,36. 36 ±3. 57. There were statistical differences between Group A and B, Group A and C( P <0. 05 ). There was no statistical difference between Group B and C ( P >0. 05 ). The V20 of normal lung tissue in Group A、B and C were respectively 23. 47 ±2. 10,25. 69 ±2. 15, 27. 69 ±2. 07. The V30 were 15. 19 ±2. 59,16. 10 ±2.57,17.23 ±2. 35. The MLD ( Gy ) were 12.58 ±1.23,13.62 ±1.19, 14. 21 ± 1. 20. The V55 of esophagus were 14.44 ± 1. 99,15. 29 ± 2. 52 ,14. 21 ± 1. 21. The maximum received-dosage of spinal cord were 37.45 ±2.39,39.38 ±2.78,40.13 ±2. 52. There were statistical differences between Group A and B,Group A and C, Group B and C ( P < 0. 05 ). Conclusion The plan of PET-CT positioned SMART of NSCLC can optimize target dose distribu-tion, lessen effectively the doses and volume of circumferential normal tissues.%目的 评价非小细胞肺癌PET-CT定位同步加量调强放射治疗(SMART)的剂量学特点.方法 ⅢA、ⅢB期非小细胞肺癌患者10例,分别于单纯增强CT图像下、PET-CT融合图像下勾画靶区,同一患者制定3种放疗计划:PET-CT图像下制定SMART计划(A组)、CT图像下制定SMART计划(B组)和3D-CRT计划(C组),评价3种放疗计划靶区、周围正常组织剂量分布情况.结果 A、B、C组GTV适形度指数分别为0.72±0.03、0.72±0.02、0.65±0.02,CTV适形度指数分别为0.64±0.03、0.64±0.02、0.53±0.03,GTV均匀性指数分别为1.14±0.02、1.15±0.02、1.12±0.02,经检验A、B组与C组比较有统计学意义(P均<0.05),A组与B组比较无统计学意义(P＞0.05).A、B、C组正常肺组织V5分别为53.41±4.90、56.09±4.61、55.87±4.27,V10分别为33.56±4.02、35.95±3.35、36.36±3.57,经检验A组与B、C组比较有统计学意义(P均<0.05),B组与C组比较无统计学意义(P＞0.05).A、B、C组正常肺组织V20分别为23.47±2.10、25.69±2.15、27.69±2.07,V30分别为15.19±2.59、16.10±2.57、17.23±2.35,MLD(Gy)分别为12.58±1.23、13.62±1.19、14.21±1.20,食管V55分别为14.44±1.99、15.29±2.52、16.12±2.50,脊髓Dmax分别为37.45±2.39、39.38±2.78、40.13±2.52,经检验,A、B、C组间比较均有统计学意义(P均<0.05).结论 非小细胞肺癌PET-CT定位SMART计划能优化靶区剂量分布,有效减少靶区周围正常组织受照剂量/体积.