【摘要】 目的:将肺灌注显像的功能信息整合到三维适形放射治疗计划的制定过程中,探讨能否优化放射治疗计划,从而更好地保护正常肺组织。方法:将行三维适形放射治疗的18例肺癌患者按缺损区与肿瘤病灶的大小分为4级。10级:无灌注受损;21级:肿瘤及其周围局部肺灌注受损;32级:达1叶肺灌注受损;43级:超过1叶肺灌注受损。选择患者单光子发射计算机断层成像术(SPECT)断层图像中放射性计数最大值≥30%作为阈值,由计算机在各个断层上自动生成感兴趣区(ROI),界定为功能正常的肺组织区域(FL)。分别参照和不参照三维肺灌注图像制定三维放射治疗计划并进行对比。结果:18例患者均有不同程度的肺动脉血流灌注受损,其中1级5例,2级7例,3级6例。在10 Gy、13 Gy、20 Gy、25 Gy、30 Gy及40 Gy的放射性剂量受量水平上,所有患者受量>x Gy的全肺容积接收剂量的百分数(≥x Gy,WLVx)和功能性正常肺容积接收剂量的百分比(≥x Gy,FLVx)均有降低,并且FLVx的降低幅度均>WLVx;在10 Gy、13 Gy、20Gy及25 Gy的剂量受量水平上,2级以上患者的FLVx降低幅度均>1级患者;在30 Gy、40 Gy的剂量受量水平上,2级以上患者的FLVx降低幅度轻微<1级患者。结论:肺灌注显像能有效优化肺癌三维放射治疗计划,保护功能正常肺组织,并且对于肺灌注缺损大的患者效果更佳。更多还原

【Abstract】 Objective: To observe whether the radiotherapy plan is optimized and normal lung tissue can be protect when lung perfusion to be integrated into the three-dimensional conformal radiotherapy planed. Methods: Eighteen lung cancer patients had performed lung perfusion scans before three-dimensional conformal radiotherapy. The defect of lung perfusion was graded using the following criteria: grade 0: no perfusion damage; grade 1: limited to the area of tumors and its surrounding lung tissue; grade 2: up to one lobe of the lung; and grade 3: beyond one lobe. Region of Interest(ROI) is automatically created in every perfusion slice by computer as Functional Lung(FL) according to the threshold which is defined more than 30 percent of the highest count in all the SPECT slices. Two sets of three-dimensional conformal radiotherapy plans are respectively made with and without the three-dimensional lung perfusion images for every patient in order to minimize the radiation dosage to lung tissue(including Whole Lung and Functional Lung).Statistical analysis is made for the difference between the parameters in two sets of radiotherapy plans using SPSS11.5. Results: All of the patients are observed with lung perfusion defect, five patients with grade 1, seven patients with grade 2 and 6 patients with grade 3 damage, respectively. For every radiation dose level of 10 Gy, 13 Gy, 20 Gy, 25 Gy, 30 Gy, and 40 Gy, the percentage of Whole Lung Volume receiving dose≥xG y(WLVx) is decreased in all patients and the percentage of Functional Lung Volume receiving dose≥xG y(FLVx) is decreased more than WLVx in all patients; For every radiation dose level of 10 Gy, 13 Gy, 20 Gy, and 25 Gy, FLVx is decreased more in ≥grade 2 group than in grade 1 group, respectively; For every radiation dose level of 30 Gy and 40 Gy, FLVx is decreased slightly less in ≥grade 2 group than in grade 1 group. Conclusion: Lung perfusion scan can effectively optimize the three-dimensional conformal radiotherapy plan for lung cancer to protect normal functional lung tissue, especially for patients with larger lung perfusion defect.更多还原