食管癌三维适形调强放疗中放射性肺损伤相关因素分析

The radio-pulmonary lesion in three-dimensional conformal intensive modulated radiotherapy of esophageal cancer

目的探讨中下段食管癌三维适形调强放疗中放射性肺损伤的相关因素,为食管癌放疗的选择提供依据。方法选取本院2011年5月至2014年5月治疗的72例食管癌患者,应用美国瓦里安直线加速器Ix-6074、Eclipse 11放疗计划系统制作计划,处方剂量(60~68)Gy/(30~34)F,95%计划靶区达到处方剂量前提下,用剂量体积直方图比较肺组织受照射时剂量体积与放射性肺损伤的关系,并探讨临床因素与放射性肺损伤的相关性。结果随访发现1年总生存率为94.44%。中下段食管癌患者的肿瘤病变长度、伴有COPD及放疗总剂量与IMRT后放射性肺损伤发生相关。72例患者中9例发生放射性肺损伤(12.50%),V10、V15、V20、V30、肺Dmean在放射性肺损伤与未发生放射性肺损伤患者中相比较有显著性差异(均P<0.05),而V5、V25、V35、V40、肺Dmax和肺Dmin在两组间相比无显著性差异(均P>0.05)。结论 V10、V15、V20、V30、肺Dmean剂量是放射性肺损伤发生的关键因素,食管癌三维适形调强放疗中放射剂量学因素可较好预测放射性肺损伤发生。

Objective To investigate the related factors of radiation-induced lung injury（RILI） in three-dimensional conformal intensity modulated radiation therapy（IMRT） for middle and lower esophageal cancer, and to provide evidence for the selection of radiotherapy for esophageal carcinoma. Methods 72 cases of esophageal cancer patients in our hospital from May 2011 to May 2014 were selected for the radiotherapy. The varian Ix-6074 linear accelerator and Eclipse 11 radiotherapy planning system was applied to produce plan, and the whole prescription dose（60~68） Gy/（30~34） F, 95% of the planning target volume（PTV） reached the prescribed dose under the premise of using dose volume histogram（DVH） of lung tissue by comparison when the irradiation dose volume and RILI, and to explore the correlation between clinical factors and RILI. Results Follow up study revealed the one-year overall survival rate of 94.44%. In the middle and lower esophageal cancer patients, the length of tumor lesion, the COPD and the total dose of radiotherapy were associated to the incidence of RILI after IMRT. 9 cases of the 72 patients had found radiation-induced lung injury（12.50%）. There was significant difference between the patients of RILI and the patients of no radioactive lung injury for the V10, V15, V20, V30 and Dmean（all P〈0.05）, however, V5, V25, V35, V40, Dmax and Dmin in the patients between the two groups showed no significant difference（all P〉0.05）. Conclusions V10, V15, V20, V30 and lung Dmean dose of lung are the key factors of RILI. Radiation dosimetry in IMRT for esophageal carcinoma can predict the incidence of radiation-induced lung injury better.