Jaén Javier, Vázquez Gonzalo, Alonso Enrique, León Antonio, Guerrero Rafael, Almansa Julio F
Department of Radiation Oncology, Puerta del Mar University Hospital, Cádiz, Spain.
Int J Radiat Oncol Biol Phys. 2006 Aug 1;65(5):1381-8. doi: 10.1016/j.ijrobp.2006.03.008. Epub 2006 Jun 6.
The aim of this study was to analyze changes in pulmonary function after radiation therapy (RT) for breast cancer.
A total of 39 consecutive eligible women, who underwent postoperative irradiation for breast cancer, were entered in the study. Spirometry consisting of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), carbon monoxide diffusing capacity (DLCO), and gammagraphic (ventilation and perfusion) pulmonary function tests (PFT) were performed before RT and 6, 12, and 36 months afterwards. Dose-volume and perfusion-weighted parameters were obtained from 3D dose planning: Percentage of lung volume receiving more than a threshold dose (Vi) and between 2 dose levels (V(i-j)). The impact of clinical and dosimetric parameters on PFT changes (Delta PFT) after RT was evaluated by Pearson correlation coefficients and stepwise lineal regression analysis.
No significant differences on mean PFT basal values (before RT) with respect to age, smoking, or previous chemotherapy (CT) were found. All the PFT decreased at 6 to 12 months. Furthermore FVC, FEV(1), and ventilation recovered almost to their previous values, whereas DLCO and perfusion continued to decrease until 36 months (-3.3% and -6.6%, respectively). Perfusion-weighted and interval-scaled dose-volume parameters (pV(i-j)) showed better correlation with Delta PFT (only Delta perfusion reached statistically significance at 36 months). Multivariate analysis showed a significant relation between pV(10-20) and Delta perfusion at 3 years, with a multiple correlation coefficient of 0.48. There were no significant differences related to age, previous chemotherapy, concurrent tamoxifen and smoking, although a tendency toward more perfusion reduction in older and nonsmoker patients was seen.
Changes in FVC, FEV1 and ventilation were reversible, but not the perfusion and DLCO. We have not found a conclusive mathematical predictive model, provided that the best model only explained 48% of the variability. We suggest the use of dose-perfused volume and interval-scaled parameters (i.e., pV(10-20)) for further studies.
本研究旨在分析乳腺癌放疗（RT）后肺功能的变化。
共有39名连续入选的符合条件的女性参与了本研究，她们均接受了乳腺癌术后放疗。在放疗前以及放疗后6个月、12个月和36个月进行了肺功能测定，包括用力肺活量（FVC）、1秒用力呼气量（FEV1）、一氧化碳弥散量（DLCO）以及γ照相术（通气和灌注）肺功能测试（PFT）。从三维剂量规划中获取剂量体积和灌注加权参数：接受超过阈值剂量（Vi）以及处于两个剂量水平之间（V(i-j)）的肺体积百分比。通过Pearson相关系数和逐步线性回归分析评估临床和剂量学参数对放疗后肺功能测试变化（ΔPFT）的影响。
在年龄、吸烟或既往化疗（CT）方面，肺功能测试基础值（放疗前）未发现显著差异。所有肺功能测试指标在6至12个月时均下降。此外，FVC、FEV(1)和通气几乎恢复到先前值，而DLCO和灌注持续下降直至36个月（分别下降3.3%和6.6%）。灌注加权和区间标度剂量体积参数（pV(i-j)）与ΔPFT显示出更好的相关性（仅Δ灌注在36个月时达到统计学显著性）。多变量分析显示3年时pV(10-20)与Δ灌注之间存在显著关系，多重相关系数为0.48。在年龄、既往化疗、同时使用他莫昔芬和吸烟方面未发现显著差异，尽管在老年和非吸烟患者中存在灌注减少更多的趋势。
FVC、FEV1和通气的变化是可逆的，但灌注和DLCO的变化不可逆。我们尚未找到一个确定性的数学预测模型，因为最佳模型仅解释了48%的变异性。我们建议在进一步研究中使用剂量灌注体积和区间标度参数（即pV(10-20)）。
