Wu Xiao-Yu, Chen Mei, Cai Gang, Cai Rong, Xu Cheng, Ou Dan, Xu Fei-Fei, Wang Yu-Jie, Li Huan, Li Min, Zhang Yi-Bin, Cao Lu, Chen Jia-Yi
Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China.
Shanghai Key Laboratory of Proton-therapy, Shanghai, China.
Int J Part Ther. 2025 Jun 24;17:101196. doi: 10.1016/j.ijpt.2025.101196. eCollection 2025 Sep.
To compare the difference in normal tissue complication probability (ΔNTCP) between proton therapy (PT) and photon therapy plans using radiation-induced lung injury (RILI) as an endpoint and to analyze its correlation with thoracic anatomic features in breast cancer patients.
A total of 409 breast cancer patients receiving photon intensity-modulated radiation therapy were randomly split into training and testing sets at an 8:2 ratio. A dose-modifying-factors (DMFs)-incorporated Lyman-Kutcher-Burman NTCP model was developed by maximum likelihood estimation with the training set to predict the risk of grade ≥ 1 RILI (CTCAE 5.0) within 1 year after radiotherapy. The DMFs stood for baseline risk factors were identified by least absolute shrinkage and selection operator regression and uni-multivariable logistic regression. After model validation, PT plans were generated for 80 patients from the dataset. The Pearson/Spearman rank correlation coefficient followed by linear regression was used to assess the correlation between anatomic features and lung ΔNTCP between photon and proton plans.
BMI ≥ 23.52 kg/m² ( = .049) and interval between last cycle of chemotherapy and radiotherapy (ICR) ≤ 20 days ( = .014) were found to be independent risk factors for RILI. The optimal NTCP parameters were: = 0.40, = 0.22, = 24.66Gy, = 0.88, and = 0.92. The model performed well in area under the receiver operating curve (training set 0.754, testing set 0.733) and other validation tests. Among the 80 patients with photon and proton plans, the mean ΔNTCP was 57.45% ± 10.51%. Linear regression showed a significant positive correlation between Arc Height to Base Ratio at the transverse plane of the sternal angle and ΔNTCP (regression coefficient 56.56, = .049).
BMI ≥ 23.52 kg/m² and ICR ≤ 20 days are risk factors for RILI. In patients with larger Arc Height to Base Ratio at the transverse plane of the sternal angle, PT plans suggest greater lung sparing in comparison to intensity-modulated radiation therapy. Further studies are needed to validate this association.
以放射性肺损伤（RILI）为终点，比较质子治疗（PT）和光子治疗计划中正常组织并发症概率（ΔNTCP）的差异，并分析其与乳腺癌患者胸部解剖特征的相关性。
将409例接受光子调强放射治疗的乳腺癌患者按8:2的比例随机分为训练集和测试集。通过最大似然估计，利用训练集建立了包含剂量修正因子（DMF）的Lyman-Kutcher-Burman NTCP模型，以预测放疗后1年内≥1级RILI（CTCAE 5.0）的风险。通过最小绝对收缩和选择算子回归以及单变量和多变量逻辑回归确定代表基线风险因素的DMF。模型验证后，从数据集中为80例患者生成PT计划。采用Pearson/Spearman等级相关系数及线性回归评估光子和质子计划中解剖特征与肺ΔNTCP之间的相关性。
发现BMI≥23.52kg/m²（P = 0.049）和化疗最后周期与放疗之间的间隔（ICR）≤20天（P = 0.014）是RILI的独立危险因素。最佳NTCP参数为：α = 0.40，β = 0.22，m = 24.66Gy，n = 0.88，p = 0.92。该模型在受试者操作曲线下面积（训练集0.754，测试集0.733）及其他验证测试中表现良好。在80例有光子和质子计划的患者中，平均ΔNTCP为57.45%±10.51%。线性回归显示，胸骨角横平面的弧高与底径比与ΔNTCP之间存在显著正相关（回归系数56.56，P = 0.049）。
BMI≥23.52kg/m²和ICR≤20天是RILI的危险因素。在胸骨角横平面弧高与底径比更大的患者中，与调强放射治疗相比，PT计划显示对肺的保护作用更大。需要进一步研究来验证这种关联。
