Department of Nuclear Medicine and Oncological Imaging, Liège, Belgium.
Department of Radiology, Liège, Belgium.
Radiother Oncol. 2021 Apr;157:47-55. doi: 10.1016/j.radonc.2021.01.001. Epub 2021 Jan 14.
Radiation recall pneumonitis (RRP) is a delayed radiation-induced lung toxicity triggered by systemic agents, typically anticancer drugs. Immune checkpoint inhibitors (ICIs) have recently been identified as potential causal agents of RRP but its real incidence and potential risk factors remain unknown.
Medical records and CTs of patients treated with programmed death 1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitors for advanced lung cancer between 2014 and 2019 at our tertiary center, and who had a previous history of lung irradiation were retrospectively analyzed. We identified RRP as lung CT modifications occurring in the irradiation field >6 months after conventionally fractionated radiotherapy completion and >1 year after stereotactic body radiation therapy. Clinical and dosimetric data were analyzed to identify potential risk factors for RRP.
Among 348 patients treated with ICIs, data from 80 eligible patients were analyzed (median age, 69 years [interquartile range, 11]; 45 men). Fifteen patients (18.8%) presented with RRP. Median time between end of radiotherapy and RRP was 450 days (range, 231-1859). No risk factor was significantly associated with RRP. ICI-related pneumonitis was associated with RRP in 33.3% of cases (p = 0.0021), developing either concomitantly or after RRP. Incidence of grade ≥ 3 pneumonitis in the RRP population was 13.3 %.
We demonstrated a high incidence of RRP (18.8%) in our population of previously irradiated patients treated with ICIs for lung cancer. We identified no risk factors for RRP, but an association was noted between RRP and ICI-related pneumonitis.
放射性回忆性肺炎（RRP）是一种由全身药物（通常为抗癌药物）引发的延迟性放射性肺毒性。免疫检查点抑制剂（ICI）最近被确定为 RRP 的潜在病因，但 RRP 的真实发病率及其潜在危险因素尚不清楚。
回顾性分析了 2014 年至 2019 年期间在我们的三级中心接受程序性死亡受体 1（PD-1）或程序性死亡配体 1（PD-L1）抑制剂治疗的晚期肺癌患者的病历和 CT，这些患者之前有过肺部放疗史。我们将 RRP 定义为在常规分割放疗结束后 6 个月以上、立体定向体部放疗后 1 年以上照射野内出现的肺部 CT 改变。分析临床和剂量学数据以确定 RRP 的潜在危险因素。
在 348 例接受 ICI 治疗的患者中，分析了 80 例符合条件的患者的数据（中位年龄 69 岁[四分位间距 11]；45 例男性）。15 例（18.8%）患者出现 RRP。放疗结束至 RRP 的中位时间为 450 天（范围 231-1859 天）。没有明显的危险因素与 RRP 相关。在 33.3%的病例中，ICI 相关的肺炎与 RRP 相关（p=0.0021），且 RRP 发生在 ICI 相关肺炎之前或同时。在 RRP 人群中，≥3 级肺炎的发生率为 13.3%。
我们在接受 ICI 治疗肺癌的既往放疗患者中发现 RRP 的发病率较高（18.8%）。我们没有发现 RRP 的危险因素，但 RRP 与 ICI 相关的肺炎之间存在关联。
