Instituto Nacional de Enfermedades Respiratorias, México City, México.
Instituto Nacional de Cancerología, México City, México.
Int J Radiat Oncol Biol Phys. 2018 Jul 15;101(4):910-918. doi: 10.1016/j.ijrobp.2018.04.014. Epub 2018 Apr 12.
In lung cancer patients, radiation therapy modifies lung architecture, resulting in functional deterioration, which worsens symptoms and reduces quality of life.
A multicenter, prospective, longitudinal study was conducted in a cohort of patients with locally advanced and oligometastatic non-small cell lung cancer treated with concurrent chemoradiation therapy (CCRT). A wide array of pulmonary function tests (forced spirometry, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity, fraction of exhaled nitric oxide, arterial blood gases, and 6-minute walk test) were used to evaluate lung function at baseline; after radiation therapy; and at 6, 12, 24, and 48 weeks after CCRT. Relative changes in test results (percentages) were estimated at the aforementioned intervals and compared with baseline results.
Thirty-seven patients completed the follow-up and were included in the analysis. After CCRT, patients showed a maximum decline in lung volumes as follows: (1) 31% in forced expiratory volume in the first second after 24 weeks (P = .008), (2) 9.6% in forced vital capacity after 48 weeks (P = .04), and (3) 15.1% in total lung capacity after 48 weeks (P = .0015). Similarly, at 12 weeks after CCRT, patients showed a 21.8% decrease in carbon monoxide diffusing capacity (P = .002). Increases were found in total airway resistance (respiratory system resistance at 5 Hz), frequency dependence of resistance (change in respiratory system resistance at 5 Hz-respiratory system resistance at 20 Hz, P = .012), and reactance (P = .0003 for respiratory system reactance at 5 Hz and P = .001 for reactance area), which together indicate small-airway dysfunction.
The longitudinal evaluation of lung function through pulmonary function tests detects CCRT-induced damage before the appearance of clinical symptoms associated with CCRT lung toxicity.
在肺癌患者中，放射治疗会改变肺部结构，导致功能恶化，从而使症状恶化，降低生活质量。
一项多中心、前瞻性、纵向研究纳入了一组接受同步放化疗（CCRT）治疗的局部晚期和寡转移非小细胞肺癌患者。使用广泛的肺功能测试（用力肺活量、体描法、脉冲震荡法、一氧化碳弥散量、呼气一氧化氮分数、动脉血气和 6 分钟步行试验）在基线时、放射治疗后以及 CCRT 后 6、12、24 和 48 周时评估肺功能。在上述各时间点估计测试结果（百分比）的相对变化，并与基线结果进行比较。
37 例患者完成了随访并纳入分析。CCRT 后，患者的肺容积最大下降如下：（1）24 周时第 1 秒用力呼气量下降 31%（P=0.008），（2）48 周时用力肺活量下降 9.6%（P=0.04），（3）48 周时总肺活量下降 15.1%（P=0.0015）。同样，CCRT 后 12 周时，患者的一氧化碳弥散量下降 21.8%（P=0.002）。总气道阻力（5Hz 时呼吸系统阻力）、阻力频率依赖性（5Hz-20Hz 时呼吸系统阻力变化，P=0.012）和电抗（5Hz 时呼吸系统电抗，P=0.0003；电抗区，P=0.001）增加，这些均表明小气道功能障碍。
通过肺功能测试对肺功能进行纵向评估，可以在出现与 CCRT 肺毒性相关的临床症状之前，检测到 CCRT 引起的损伤。
