Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas, United States of America.
Department of Statistics, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
PLoS One. 2020 Nov 30;15(11):e0241505. doi: 10.1371/journal.pone.0241505. eCollection 2020.
Radiation-induced lymphopenia (RIL) occurs during treatment with conventional radiation in multiple organ sites. Development of RIL portends poor prognosis. Stereotactic body radiation therapy (SBRT) spares RIL in pancreatic cancer, but has not been examined in other sites commonly treated with SBRT. This work examines if SBRT similarly spares RIL in patients with non-small cell lung cancer (NSCLC).
Retrospective analysis was done at a single institution on 40 distinct cases of SBRT for early stage NSCLC from 2006-2017. Incidentally collected lymphocyte counts collected within 6 months of SBRT treatment were analyzed to determine if RIL occurred. The presence of RIL was correlated with location of initial failure and survival endpoints. Kaplan-Meier curves were constructed with significance defined at the level p < 0.05.
RIL was observed in 35% of the analyzed patients. Patterns of failure and survival data were comparable to prior SBRT literature. There was no observed association in two year local, nodal, or distant failure, progression free survival, or overall survival based on the presence of RIL.
SBRT spares RIL in NSCLC compared to historical rates observed with conventionally fractionated radiation. As understanding of the role of the immune system in cancer control continues to evolve, the importance of RIL sparing techniques take on increasing importance. This study represents further analysis of RIL sparing in SBRT in an early stage NSCLC cohort without the confounding influence of chemotherapy.
在多个器官部位接受常规放射治疗时会发生放射性淋巴细胞减少症（RIL）。RIL 的发展预示着预后不良。立体定向体部放射治疗（SBRT）可避免胰腺癌中的 RIL，但尚未在其他常用 SBRT 治疗的部位进行检查。这项工作研究了 SBRT 是否同样可避免非小细胞肺癌（NSCLC）患者的 RIL。
在一家机构对 2006 年至 2017 年间进行的 40 例早期 NSCLC 的 SBRT 进行了回顾性分析。分析了 SBRT 治疗后 6 个月内偶然收集的淋巴细胞计数，以确定是否发生 RIL。RIL 的存在与初始失败的部位和生存终点相关。使用 Kaplan-Meier 曲线进行构建，显著性定义为 p < 0.05。
在分析的患者中，有 35％观察到 RIL。失败模式和生存数据与先前的 SBRT 文献相似。根据 RIL 的存在，未观察到两年局部、淋巴结或远处失败、无进展生存期或总生存期之间存在关联。
与常规分割放疗观察到的历史比率相比，SBRT 可避免 NSCLC 中的 RIL。随着对免疫系统在癌症控制中的作用的理解不断发展，RIL 保护技术的重要性越来越重要。这项研究代表了在没有化疗混杂影响的情况下，对早期 NSCLC 队列中 SBRT 的 RIL 保护进行的进一步分析。
