Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.
Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
Cancer Res Treat. 2023 Jul;55(3):875-884. doi: 10.4143/crt.2022.1583. Epub 2023 Feb 24.
We aimed to evaluate the effectiveness of prophylactic cranial irradiation (PCI) for "early brain metastasis", which occurs before extracranial recurrence (ECR), and "late brain metastasis", which occurs after ECR, in limited-stage small cell lung cancer (LS-SCLC).
We retrospectively analyzed 271 LS-SCLC patients who underwent definitive chemoradiation. All patients were initially staged with brain magnetic resonance imaging and positron emission tomography. Intracranial recurrence (ICR), ECR, progression-free rate (PFR), and overall survival (OS) were analyzed as clinical endpoints. The competing risk of the first recurrence with ICR (ICRfirst) was evaluated. Significantly associated variables in multivariate analysis of ECR were considered as ECR risk factors. Patients were stratified according to the number of ECR risk factors.
The application of PCI was associated with higher PFR (p=0.008) and OS (p=0.045). However, PCI was not associated with any of the clinical endpoints in multivariate analysis. The competing risk of ICRfirst was significantly decreased with the application of PCI (hazard ratio, 0.476; 95% confidence interval, 0.243 to 0.931; p=0.030). Stage III disease, sequential, and stable disease after thoracic radiation were selected as ECR risk factors. For patients without these risk factors, the application of PCI was significantly associated with increased OS (p=0.048) and a decreased risk of ICRfirst (p=0.026).
PCI may play a role in preventing early brain metastasis rather than late brain metastasis after ECR, suggesting that only patients with a low risk of ECR may currently benefit from PCI.
我们旨在评估预防性颅脑照射（PCI）对“早期脑转移”（即在颅外复发（ECR）之前发生的脑转移）和“晚期脑转移”（即在 ECR 之后发生的脑转移）的疗效，用于局限期小细胞肺癌（LS-SCLC）患者。
我们回顾性分析了 271 例接受根治性放化疗的 LS-SCLC 患者。所有患者最初均进行了脑部磁共振成像和正电子发射断层扫描检查。颅内复发（ICR）、ECR、无进展生存率（PFR）和总生存率（OS）作为临床终点进行分析。评估了 ICR 首次复发（ICRfirst）的首次复发竞争风险。多变量分析中与 ECR 显著相关的变量被认为是 ECR 的危险因素。根据 ECR 危险因素的数量对患者进行分层。
应用 PCI 与较高的 PFR（p=0.008）和 OS（p=0.045）相关。然而，PCI 在多变量分析中与任何临床终点均无关。ICRfirst 的竞争风险随着 PCI 的应用而显著降低（危险比，0.476；95%置信区间，0.243 至 0.931；p=0.030）。III 期疾病、序贯治疗和胸部放疗后稳定的疾病被选为 ECR 的危险因素。对于没有这些危险因素的患者，应用 PCI 与 OS 增加显著相关（p=0.048），且 ICRfirst 的风险降低（p=0.026）。
PCI 可能在预防 ECR 后早期脑转移而非晚期脑转移方面发挥作用，这表明只有 ECR 风险较低的患者可能会从 PCI 中受益。
