Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, USA.
Int J Radiat Oncol Biol Phys. 2012 May 1;83(1):427-34. doi: 10.1016/j.ijrobp.2011.06.1971. Epub 2011 Dec 23.
Recent studies with two fractionation schemes predicted that the volume of chest wall receiving >30 Gy (V30) correlated with chest wall pain after stereotactic body radiation therapy (SBRT) to the lung. This study developed a predictive model of chest wall pain incorporating radiobiologic effects, using clinical data from four distinct SBRT fractionation schemes.
102 SBRT patients were treated with four different fractionations: 60 Gy in three fractions, 50 Gy in five fractions, 48 Gy in four fractions, and 50 Gy in 10 fractions. To account for radiobiologic effects, a modified equivalent uniform dose (mEUD) model calculated the dose to the chest wall with volume weighting. For comparison, V30 and maximum point dose were also reported. Using univariable logistic regression, the association of radiation dose and clinical variables with chest wall pain was assessed by uncertainty coefficient (U) and C statistic (C) of receiver operator curve. The significant associations from the univariable model were verified with a multivariable model.
106 lesions in 102 patients with a mean age of 72 were included, with a mean of 25.5 (range, 12-55) months of follow-up. Twenty patients reported chest wall pain at a mean time of 8.1 (95% confidence interval, 6.3-9.8) months after treatment. The mEUD models, V30, and maximum point dose were significant predictors of chest wall pain (p < 0.0005). mEUD improved prediction of chest wall pain compared with V30 (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.11). The mEUD with moderate weighting (a = 5) better predicted chest wall pain than did mEUD without weighting (a = 1) (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.14). Body mass index (BMI) was significantly associated with chest wall pain (p = 0.008). On multivariable analysis, mEUD and BMI remained significant predictors of chest wall pain (p = 0.0003 and 0.03, respectively).
mEUD with moderate weighting better predicted chest wall pain than did V30, indicating that a small chest wall volume receiving a high radiation dose is responsible for chest wall pain. Independently of dose to the chest wall, BMI also correlated with chest wall pain.
最近的两项分割方案研究预测，立体定向体部放射治疗（SBRT）后，胸壁接受>30Gy（V30）的体积与胸壁疼痛相关。本研究采用来自四种不同 SBRT 分割方案的临床数据，建立了包含放射生物学效应的胸壁疼痛预测模型。
102 例 SBRT 患者接受了四种不同分割方式的治疗：3 次分割 60Gy、5 次分割 50Gy、4 次分割 48Gy、10 次分割 50Gy。为了考虑放射生物学效应，采用改良等效均匀剂量（mEUD）模型，对胸壁体积进行剂量加权计算。为了进行比较，还报告了 V30 和最大点剂量。采用单变量逻辑回归，通过不确定性系数（U）和接收者操作特征曲线的 C 统计量（C）评估放射剂量和临床变量与胸壁疼痛的相关性。单变量模型中具有显著相关性的变量通过多变量模型进行验证。
共纳入 102 例患者的 106 个病灶，平均年龄为 72 岁，随访时间平均为 25.5（范围 12-55）个月。20 例患者在治疗后平均 8.1（95%置信区间 6.3-9.8）个月时报告有胸壁疼痛。mEUD 模型、V30 和最大点剂量均是胸壁疼痛的显著预测因子（p<0.0005）。mEUD 对胸壁疼痛的预测优于 V30（C=0.79 与 0.77，U=0.16 与 0.11）。中度加权（a=5）的 mEUD 优于无权重（a=1）的 mEUD（C=0.79 与 0.77，U=0.16 与 0.14）。体重指数（BMI）与胸壁疼痛显著相关（p=0.008）。多变量分析显示，mEUD 和 BMI 仍然是胸壁疼痛的显著预测因子（p=0.0003 和 0.03）。
中度加权的 mEUD 比 V30 更好地预测胸壁疼痛，表明小的胸壁体积接受高剂量的放射是导致胸壁疼痛的原因。独立于胸壁剂量，BMI 也与胸壁疼痛相关。
