Kim Jae Sik, Chang Ah Ram
Department of Radiation Oncology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, Republic of Korea.
Front Oncol. 2023 Oct 6;13:1243053. doi: 10.3389/fonc.2023.1243053. eCollection 2023.
In this study, we aimed to assess the abscopal effect (AE) after CyberKnife stereotactic body radiotherapy (SBRT) in metastatic breast cancer patients without immunotherapy.
We reviewed breast cancer patients who received SBRT with a fraction size of ≥ 6 Gy for metastatic lesions between July 2008 and December 2021. We selected patients who had at least one measurable extracranial lesion in addition to SBRT target lesions and were not treated with immunotherapy. A total of 40 SBRT cases from 34 patients were included in the analysis. The AE was defined as occurring before the overall progression of the disease, regardless of the use of systemic treatment.
The median follow-up duration was 16.4 months. Among 40 SBRT cases, the AE was observed in 10 (25.0%) with a median interval of 2.1 months. Of these lesions, 70.0% did not progress for one year. In multivariate logistic regression analysis, no change in systemic treatment after SBRT was significantly associated with an increase in the AE (odds ratio [OR] = 1.428, 95% confidence interval [CI] = 1.108 - 1.841, p = 0.009). A post-SBRT neutrophil-to-lymphocyte ratio (NLR) of < 2 marginally increased the AE (OR = 1.275, 95% CI = 0.998 - 1.629, p = 0.060). However, a high SBRT dose and large planning target volume did not (p = 0.858 and 0.152, respectively) in univariate analysis.
One out of four patients experienced the AE after SBRT in the absence of immunotherapy. The AE could occur more frequently when systemic treatment remains unchanged, and patients have a low NLR after SBRT.
在本研究中，我们旨在评估在未接受免疫治疗的转移性乳腺癌患者中，射波刀立体定向体部放射治疗（SBRT）后的远隔效应（AE）。
我们回顾了2008年7月至2021年12月期间接受SBRT治疗、转移灶分次剂量≥6 Gy的乳腺癌患者。我们选择了除SBRT靶病灶外至少有一个可测量颅外病灶且未接受免疫治疗的患者。分析纳入了来自34例患者的40例SBRT病例。AE被定义为在疾病总体进展之前出现，无论是否使用全身治疗。
中位随访时间为16.4个月。在40例SBRT病例中，10例（25.0%）观察到AE，中位间隔时间为2.1个月。在这些病灶中，70.0%在一年内未进展。在多因素逻辑回归分析中，SBRT后全身治疗无变化与AE增加显著相关（比值比[OR]=1.428，95%置信区间[CI]=1.108 - 1.841，p = 0.009）。SBRT后中性粒细胞与淋巴细胞比值（NLR）<2使AE略有增加（OR = 1.275，95% CI = 0.998 - 1.629，p = 0.060）。然而，在单因素分析中，高SBRT剂量和大计划靶体积并未导致AE增加（p分别为0.858和0.152）。
在未接受免疫治疗的情况下，四分之一的患者在SBRT后出现AE。当全身治疗保持不变且患者SBRT后NLR较低时，AE可能更频繁地发生。
