Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Int J Radiat Oncol Biol Phys. 2012 Feb 1;82(2):981-8. doi: 10.1016/j.ijrobp.2010.08.041. Epub 2011 Mar 4.
Radiation pneumonitis is a major toxicity after thoracic radiotherapy (RT), with no method available to accurately predict the individual risk. This was a prospective study to evaluate exhaled nitric oxide as a predictive biomarker for radiation pneumonitis in esophageal cancer patients.
A total of 34 patients prescribed neoadjuvant chemoradiotherapy for esophageal cancer were enrolled in the present trial. Each patient underwent respiratory surveys and exhaled nitric oxide (NO) measurements before, at the end of, and 1 to 2 months after completing RT. Pneumonitis toxicity was scored using the Common Terminology Criteria for Adverse Events, version 4.0. The demographics, dosimetric factors, and exhaled NO levels were evaluated for correlation with symptomatic patients (scores ≥ 2).
Of the 34 patients, 28 were evaluable. All had received 50.4 Gy RT with concurrent chemotherapy. The pneumonitis toxicity score was Grade 3 for 1, Grade 2 for 3, Grade 1 for 7, and Grade 0 for 17. The dosimetric factors were not predictive of symptoms. The mean exhaled NO level measured before, at completion, and at restaging was 17.3 ± 8.5 (range, 5.5-36.7), 16.0 ± 14.2 (range, 5.8-67.7), and 14.7 ± 6.2 (range, 5.5-28.0) parts per billion, respectively. The ratio of exhaled NO at the end of RT vs. before treatment was 3.4 (range, 1.7-6.7) for the symptomatic and 0.8 (range, 0.3-1.3) for the asymptomatic (p = .0017) patients. The elevation in exhaled NO preceded the peak symptoms by 33 days (range, 21-50). The interval to peak symptoms was inversely related to the exhaled NO elevation.
Elevations in exhaled NO at the end of RT was found to predict for radiation pneumonitis symptoms.
放射性肺炎是胸部放疗（RT）后的一种主要毒性，目前尚无准确预测个体风险的方法。本研究前瞻性评估呼出气一氧化氮（FeNO）作为食管癌患者放射性肺炎的预测生物标志物。
本研究共纳入 34 例接受新辅助放化疗的食管癌患者。每位患者在接受 RT 前、结束时和结束后 1-2 个月接受呼吸调查和呼出气一氧化氮（NO）测量。采用不良事件通用术语标准 4.0 对肺炎毒性进行评分。评估患者的人口统计学、剂量学因素和呼出气一氧化氮水平与有症状患者（评分≥2）的相关性。
34 例患者中，28 例可评估。所有患者均接受 50.4 Gy RT 联合化疗。肺炎毒性评分 3 级 1 例，2 级 3 例，1 级 7 例，0 级 17 例。剂量学因素与症状无相关性。治疗前、治疗结束时和再分期时呼出气一氧化氮的平均值分别为 17.3±8.5（范围 5.5-36.7）、16.0±14.2（范围 5.8-67.7）和 14.7±6.2（范围 5.5-28.0）ppb。症状组治疗结束时与治疗前呼出气一氧化氮比值为 3.4（范围 1.7-6.7），无症状组为 0.8（范围 0.3-1.3）（p=0.0017）。呼出气一氧化氮升高先于症状高峰 33 天（范围 21-50）。症状高峰至呼出气一氧化氮升高的时间间隔与呼出气一氧化氮升高呈反比。
治疗结束时呼出气一氧化氮升高可预测放射性肺炎症状。
