论文部分内容阅读
目的比较乳腺癌改良根治术后CT模拟定位与模拟机定位(或体表画线)剂量学的差异。方法对83例已行乳腺癌改良根治术拟行放射治疗的患者进行CT模拟定位,同时应用模拟机模拟常规治疗计划,根据剂量-体积直方图(DVH),比较患者采用2种治疗计划的患侧及双肺的V5、V10、V20、V30、计划靶区(PTV)接受40 Gy、45 Gy和50 Gy(PTV40、PTV45、PTV50)的体积百分比、PTV>60、PTV>70的体积百分比及靶区内受照最大剂量(MAX)的差异;比较两种定位模式与患者胸壁厚度的关系,并跟踪随访患者放射性肺炎发生情况。结果患者常规治疗患侧及双肺V5、V10、V20、V30以及PTV40、PTV45、PTV50百分比均小于CT模拟定位计划结果,常规治疗PTV>60、PTV>70的百分比及MAX均大于CT模拟定位计划结果。患者平均胸壁厚度为22.9 mm,常规治疗PTV覆盖及正常组织受量与胸壁厚度呈负相关,CT模拟定位PTV覆盖及正常组织受量与胸壁厚度无相关关系。患者3年随访率达90.4%,放射性肺炎发生率为12.0%(9/75)。结论乳腺癌改良根治术后胸壁电子线照射CT模拟定位靶区涵盖优于模拟机定位的常规治疗计划,肺受量常规治疗计划优于CT模拟定位,但放射性肺炎发生率未见提高。在乳腺癌改良根治术后放射治疗中,CT模拟定位较单纯模拟机定位有明显的优越性。
Objective To compare the difference of dosimetry between CT simulated positioning and simulator positioning (or body surface drawing) after modified radical mastectomy for breast cancer. Methods Eighty-three patients undergoing radical mastectomy for radical mastectomy undergoing radiotherapy were underwent CT simulation. At the same time, a routine simulator was used to simulate the routine treatment plan. According to the dose-volume histogram (DVH), patients with two kinds of treatment plans were compared Volume percentage of PTV> 40, PTV> 70, volume percentage of PTV> 70 and PTV of 40 Gy, 45 Gy and 50 Gy (PTV40, PTV45, PTV50) in V5, V10, V20, (MAX). The relationship between the two location patterns and chest wall thickness was compared and the incidence of radiation pneumonitis was followed up. Results The percentages of V5, V10, V20, V30, PTV40, PTV45 and PTV50 in the affected side and the lungs of the patients were less than those of the CT simulation. The percentage of PTV> 60, PTV> 70 and MAX in the routine treatment were higher than those in the CT simulation result. The mean thoracic wall thickness was 22.9 mm. The PTV coverage and normal tissue volume were negatively correlated with the thoracic wall thickness. There was no correlation between the thoracic wall thickness and the thickness of PTV. The 3-year follow-up rate was 90.4% and the incidence of radiation pneumonitis was 12.0% (9/75). CONCLUSIONS: The target area of chest wall electron beam irradiation CT simulation after modified radical mastectomy covers the conventional treatment plan which is better than the simulator positioning. The conventional treatment plan of lung volume is superior to CT simulation positioning, but the incidence of radiation pneumonitis is not improved. Radiotherapy after modified radical mastectomy in breast cancer, CT simulation positioning than simple simulation machine has obvious advantages.