背景:目前,放射治疗计划系统旨在进行生物学优化,该优化在很大程度上依赖于肿瘤控制概率(TCP)和正常组织并发症概率(NTCP)建模的计划指标。使用替代数据实施和扩展TCP和NTCP模型是朝着可靠的放射生物学治疗计划迈出的重要一步。在这项回顾性的单一机构研究中,回顾了139例接受放化疗的肺癌患者的治疗图,并将剂量学预测因子与食管炎的发生率相关联,并为肺癌患者建立了1级和2级食管炎的NTCP模型。
方法:食管是肺癌放疗(RT)中的危险器官(OAR)。食管炎是由RT引起的常见毒性。在这项研究中,剂量体积参数Vx(Vx:接受≥xGy的食管体积百分比)和平均食管剂量(MED)作为定量剂量体积指标,以1级和2级食管炎为终点,进行了审查,并从治疗计划系统和电子病历系统中得出。进行二元逻辑回归和probit的统计分析,以将1级和2级食管炎的概率与MED和Vx相关联。在统计学分析中使用5%显着水平(α=0.05)的IBMSPSS软件版本24。
结果:随着Vx和MED值的增加,1级和2级食管炎的发生概率成比例增加。V20、V30、V40、V50和MED是1级食管炎的统计学显著的良好剂量学预测因子。确定了1级和2级食管炎的MED发生率为50%(TD50)。LymanKutcherBurman模型参数,例如,n,m和TD50进行拟合,并与其他已发表的研究结果进行比较。此外,1级食管炎概率与MED之间的S形剂量反应曲线是根据种族产生的,性别,年龄和吸烟状况。
结论:将V20、V30、V40和V50加入到临床正常组织效应的定量分析中,或QUANTEC组的V35,V50,V70和MED的剂量限制。我们的发现可用于验证3维计划时代模型以及使用放射生物学优化进行治疗计划和计划评估的其他临床指南。
BACKGROUND: Currently, radiation therapy treatment planning system intends biological optimization that relies heavily upon plan metrics from tumor control probability (TCP) and normal tissue complication probability (NTCP) modeling. Implementation and expansion of TCP and NTCP models with alternative data is an important step towards reliable radiobiological treatment planning. In this retrospective single institution study, the treatment charts of 139 lung cancer patients treated with chemo-radiotherapy were reviewed and correlated dosimetric predictors with the incidence of esophagitis and established NTCP model of esophagitis grade 1 and 2 for lung cancer patients.
METHODS: Esophagus is an organ at risk (OAR) in lung cancer radiotherapy (RT). Esophagitis is a common toxicity induced by RT. In this study, dose volume parameters Vx (Vx: percentage esophageal volume receiving ≥ x Gy) and mean esophagus dose (MED) as quantitative dose-volume metrics, the esophagitis grade 1 and 2 as endpoints, were reviewed and derived from the treatment planning system and the electronic medical record system. Statistical analysis of binary logistic regression and probit were performed to have correlated the probability of grade 1 and 2 esophagitis to MED and Vx. IBM SPSS software version 24 at 5% significant level (α = 0.05) was used in the statistical analysis.
RESULTS: The probabilities of incidence of grade 1 and 2 esophagitis proportionally increased with increasing the values of Vx and MED. V20, V30, V40, V50 and MED are statistically significant good dosimetric predictors of esophagitis grade 1. 50% incidence probability (TD50) of MED for grade 1 and 2 esophagitis were determined. Lyman Kutcher Burman model parameters, such as, n, m and TD50, were fitted and compared with other published findings. Furthermore, the sigmoid shaped dose responding curve between probability of esophagitis grade 1 and MED were generated respecting to races, gender, age and smoking status.
CONCLUSIONS: V20, V30, V40 and V50 were added onto Quantitative Analysis of Normal Tissue Effects in the clinic, or QUANTEC group\'s dose constrains of V35, V50, V70 and MED. Our findings may be useful as both validation of 3-Dimensional planning era models and also additional clinical guidelines in treatment planning and plan evaluation using radiobiology optimization.