Department of Radiotherapy, General Hospital of Ningxia Medical University.
Department of Radiotherapy, General Hospital of Ningxia Medical University;
J Vis Exp. 2024 Aug 9(210). doi: 10.3791/67243.
Small cell lung cancer (SCLC) has garnered significant attention due to its high malignancy, propensity for distant metastasis, and poor prognosis. Radiotherapy remains the cornerstone of treatment for limited-stage small cell lung cancer (LS-SCLC). However, outcomes with radiotherapy alone or in combination with chemotherapy remain suboptimal. Radiotherapy can induce lymphopenia by directly irradiating hematopoietic organs or destroying mature circulating lymphocytes, leading to immunosuppression and consequently diminishing therapeutic efficacy. The estimated dose of radiation to immune cells (EDRIC) model integrates factors such as hemodynamics, lymphocyte radiosensitivity, and proliferation capacity. This study employs the EDRIC model with enhancements to calculate the circulating immune cell radiation dose. By utilizing the EDRIC methodology, the study explores the correlation between EDRIC and tumor target size, average lung dose, average heart dose, clinical features, and peripheral blood lymphocytopenia during radiotherapy for LS-SCLC, aiming to inform personalized patient treatment strategies. This study analyzed data from 64 LS-SCLC patients who met the inclusion criteria at the General Hospital of Ningxia Medical University from January 2023 to January 2024, all of whom received radical thoracic conventional fractionated radiotherapy. Lymphocyte counts were recorded at the following points: before radiotherapy, at the lowest observed value during radiotherapy, at the end of radiotherapy, and one-month post-radiotherapy. Dosimetric data, including average lung, heart, and body doses, were extracted from the treatment planning system, and the circulating EDRIC was calculated using this model. The relationship between EDRIC values and therapeutic outcomes was analyzed. In LS-SCLC, the EDRIC model effectively predicts lymphocyte count reduction, correlating with planning target volume (PTV; cm), TNM stage, and the percentage of target lesion shrinkage. Post-radiotherapy, there was a significant decrease in peripheral blood lymphocyte counts, with greater EDRIC values indicating more pronounced lymphocyte reduction.
小细胞肺癌（SCLC）由于其高度恶性、倾向远处转移和预后不良而备受关注。放射治疗仍然是局限期小细胞肺癌（LS-SCLC）的治疗基石。然而，单独放疗或联合化疗的疗效仍不理想。放射治疗通过直接照射造血器官或破坏成熟的循环淋巴细胞来诱导淋巴细胞减少，导致免疫抑制，从而降低治疗效果。免疫细胞放射剂量估计（EDRIC）模型综合了血液动力学、淋巴细胞放射敏感性和增殖能力等因素。本研究采用改进后的 EDRIC 模型计算循环免疫细胞的放射剂量。利用 EDRIC 方法，研究探讨了 EDRIC 与肿瘤靶区大小、平均肺剂量、平均心脏剂量、临床特征和 LS-SCLC 放疗期间外周血淋巴细胞减少之间的相关性，旨在为个体化患者治疗策略提供信息。本研究分析了 2023 年 1 月至 2024 年 1 月宁夏医科大学总医院符合纳入标准的 64 例 LS-SCLC 患者的数据，所有患者均接受根治性胸部常规分割放疗。在以下时间点记录淋巴细胞计数：放疗前、放疗期间观察到的最低值、放疗结束时和放疗后一个月。从治疗计划系统中提取剂量学数据，包括平均肺、心脏和全身剂量，并使用该模型计算循环 EDRIC。分析 EDRIC 值与治疗结果之间的关系。在 LS-SCLC 中，EDRIC 模型可有效预测淋巴细胞计数减少，与计划靶区（PTV；cm）、TNM 分期和靶病灶缩小百分比相关。放疗后，外周血淋巴细胞计数显著下降，EDRIC 值越大，淋巴细胞减少越明显。
