Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Sidney Kimmel Cancer Center, 401 N Broadway, Baltimore, MD, 21231, USA.
Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ, 08901, USA.
Radiat Oncol. 2021 Dec 24;16(1):242. doi: 10.1186/s13014-021-01969-1.
The purpose of this study was to determine if vertebral body and splenic dosimetry was associated with the development of lymphopenia in patients with borderline resectable (BRPC) and locally advanced pancreatic cancer (LAPC) treated with stereotactic body radiation therapy (SBRT).
Patients with BRPC/LAPC who were treated with SBRT and who had lymphocyte counts and radiation treatment plans available for review were included in the study. Vertebral body levels T11-L3 and the spleen were retrospectively contoured for each patient. Univariate (UVA) and multivariable analyses (MVA) were performed to identify associations between vertebral body and splenic dosimetric parameters with absolute lymphocyte count (ALC) and grade ≥ 2 lymphopenia. Receiver operator characteristic curves were generated to identify dose-volume thresholds in predicting grade ≥ 2 lymphopenia.
A total of 132 patients were included in the study. On UVA and MVA, vertebral V15 (regression coefficient [β]: - 0.026, 95% CI - 0.044 to - 0.009, p = 0.003), vertebral V2.5 (β: - 0.011, 95% CI - 0.020 to - 0.002, p = 0.015), and logPTV (β: - 0.15, 95% CI - 0.30 to - 0.005, p = 0.042) were associated with post-SBRT ALC. On UVA and MVA, vertebral V15 (odds ratio [OR]: 3.98, 95% CI 1.09-14.51, p = 0.027), vertebral V2.5 (OR: 1.04, 95% CI 1.00-1.09, p = 0.032), and spleen V10 (OR: 1.05, 95% CI 1.09-1.95, p = 0.004) were associated with development of grade ≥ 2 lymphopenia. Development of grade ≥ 2 lymphopenia was more likely in patients with vertebral V15 ≥ 5.84% (65.5% vs 34.0%, p = 0.002), vertebral V2.5 ≥ 48.36% (48.9% vs 23.8%, p = 0.005), and spleen V10 ≥ 4.17% (56.2% vs 26.9%, p < 0.001).
Increasing radiation dose to vertebral bodies and spleen were associated with the development of lymphopenia in BRPC/LAPC treated with SBRT. Optimization of vertebral body and splenic dosimetry may reduce the risk of developing lymphopenia and improve clinical outcomes in this population.
本研究旨在确定对于接受立体定向体部放射治疗（SBRT）的边界可切除（BRPC）和局部晚期胰腺癌（LAPC）患者，椎体和脾脏剂量学是否与淋巴细胞减少症的发生有关。
本研究纳入了接受 SBRT 治疗且淋巴细胞计数和放射治疗计划可供回顾的 BRPC/LAPC 患者。对每位患者的 T11-L3 椎体水平和脾脏进行回顾性勾画。采用单变量分析（UVA）和多变量分析（MVA）来确定椎体和脾脏剂量学参数与绝对淋巴细胞计数（ALC）和 2 级及以上淋巴细胞减少症之间的关联。绘制受试者工作特征曲线以确定预测 2 级及以上淋巴细胞减少症的剂量-体积阈值。
本研究共纳入了 132 例患者。在 UVA 和 MVA 中，椎体 V15（回归系数 [β]：-0.026，95%置信区间-0.044 至-0.009，p=0.003）、椎体 V2.5（β：-0.011，95%置信区间-0.020 至-0.002，p=0.015）和 logPTV（β：-0.15，95%置信区间-0.30 至-0.005，p=0.042）与 SBRT 后 ALC 相关。在 UVA 和 MVA 中，椎体 V15（比值比 [OR]：3.98，95%置信区间 1.09-14.51，p=0.027）、椎体 V2.5（OR：1.04，95%置信区间 1.00-1.09，p=0.032）和脾脏 V10（OR：1.05，95%置信区间 1.09-1.95，p=0.004）与 2 级及以上淋巴细胞减少症的发生相关。椎体 V15 剂量≥5.84%（65.5%比 34.0%，p=0.002）、椎体 V2.5 剂量≥48.36%（48.9%比 23.8%，p=0.005）和脾脏 V10 剂量≥4.17%（56.2%比 26.9%，p<0.001）的患者发生 2 级及以上淋巴细胞减少症的可能性更高。
对于接受 SBRT 治疗的 BRPC/LAPC 患者，椎体和脾脏的放射剂量增加与淋巴细胞减少症的发生有关。优化椎体和脾脏的剂量学可能会降低发生淋巴细胞减少症的风险，并改善该人群的临床结局。
