非小细胞肺癌肿瘤体积大小对调强放射治疗肺剂量体积参数的影响

发布时间：2018-07-17 01:09

【摘要】：目的:探索非小细胞肺癌(non-small cell lung cancer,NSCLC)肿瘤体积大小对调强放射治疗(intensity modulated radiation therapy,IMRT)肺剂量学参数的影响,为制定IMRT计划时限定肺剂量参数提供参考依据。方法:回顾性分析2009年6月至2013年10月行IMRT的NSCLC共204例,将原发灶的计划靶区(planning target volume,PTV)处方剂量设定为60~66 Gy(2.00~2.25 Gy/次,共27~33次)。分析正常肺组织接受放射剂量高于5或20 Gy照射的体积百分比(fractional volume percent of the lung receiving a dose5 or 20 Gy,V_5,V_(20))、正常肺组织接受放射剂量低于5 Gy的绝对体积(absolute volume of lung spared from receiving a dose5 Gy,AVS5)、平均肺剂量(mean lung dose,MLD),并采用回归模型进行曲线拟合来分析它们随原发灶肿瘤体积大小的变化所呈现的变化规律。结果:V_5,V_(20)和MLD随肿瘤体积的变化呈二次方程的曲线变化规律,而AVS5呈对数方程曲线变化规律。当肿瘤体积分别低于某一数值(依次为294.6,283.2,304.9 cm~3)时,肺V_5,V_(20)和MLD随肿瘤体积增大而呈二次曲线性增大;而当肿瘤体积分别高于某一数值(依次为294.6,283.2,304.9 cm3)时,肺V_5,V_(20)和MLD随肿瘤体积增大而呈二次曲线性下降。肺AVS5随肿瘤体积的增大呈对数曲线下降。结论:随着肺肿瘤体积的的不断增大,V_5,V_(20)和MLD和AVS5的变化规律有所不同;当肿瘤体积超过一定界值(大约为300 cm3时,相对应的肿瘤直径为7~8 cm)后,制定NSCLC调强放射治疗计划时除关注肺V_5,V_(20)和MLD外,还应更加重视AVS5的限制。
[Abstract]:Objective: to investigate the effect of tumor volume on lung dosimetry parameters in patients with non-small cell lung cancer after (intensity modulated radiation therapy. Methods: 204 cases of IMRT were analyzed retrospectively from June 2009 to October 2013. The prescribed dose of (planning target volume in the planned target area of primary focus was set to 606Gy (2.000.2.25 Gy / time, 270.33 times). Analysis of the volume percentage of normal lung tissues exposed to radiation dose above 5 or 20 Gy (fractional volume percent of the lung receiving a dose5 or 20 Gy V 5 V _ (20),). Absolute volume (absolute volume of lung spared from receiving a dose5 Gyr AVS5 of less than 5 Gy in normal lung tissue. Mean lung dose (mean lung dosedoe), and the regression model was used to curve fit to analyze their changes with the size of the primary tumor. Results the changes of V20 and MLD with tumor volume showed the curve of quadratic equation, while AVS5 showed the law of logarithmic curve. When the tumor volume was lower than a certain value (294.6283.2304.9 cm~3), the lung V5V _ (20) and MLD increased with the tumor volume increasing, while the tumor volume was higher than a certain value (294.6283.2304.9 cm3). Lung V5 V _ (20) and MLD decreased in conic with tumor volume. Lung AVS 5 decreased in logarithmic curve with the increase of tumor volume. Conclusion: the changes of V5V _ (20), MLD and AVS5 are different with the increasing of lung tumor volume, and when the tumor volume exceeds a certain limit (about 300 cm3, the corresponding tumor diameter is 7 ~ 8 cm). More attention should be paid to the limitation of AVS5 in addition to V5V _ (20) and MLD when formulating NSCLC intensity modulated radiotherapy plan.
【作者单位】：福建医科大学附属第一医院放射治疗科放射生物福建省高等学校重点实验室福建省肿瘤个体化主动免疫治疗重点实验室;
【基金】：福建省卫生厅青年科研基金(2013-01-30) 福建省医学创新基金(2012-CX-20)~~
【分类号】：R730.55;R734.2

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