Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Switzerland; Department of Radiation Oncology, University Hospital Wuerzburg, Germany.
Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Switzerland.
Radiother Oncol. 2021 Jun;159:168-175. doi: 10.1016/j.radonc.2021.03.022. Epub 2021 Mar 30.
To evaluate the impact of the distance between treatment isocenter and brain metastases on local failure in patients treated with a frameless linear-accelerator-based single-isocenter volumetric modulated arc (VMAT) SRS/SRT for multiple brain metastases.
Patients treated with SRT for brain metastases (BM) between April 2014 and May 2019 were included in this retrospective study. BM treated with a single-isocenter multiple-target (SIMT) SRT were evaluated for local recurrence-free intervals in dependency to their distance to the treatment isocenter. A Cox-regression model was used to investigate different predictor variables for local failure. Results were compared to patients treated with a single-isocenter-single-target (SIST) approach.
In total 315 patients with a cumulative number of 1087 BM were analyzed in this study of which 140 patients and 708 BM were treated with SIMT SRS/SRT. Median follow-up after treatment was 13.9 months for SIMT approach and 11.9 months for SIST approach. One-year freedom from local recurrence was 87% and 94% in the SIST and SIMT group, respectively. Median distance to isocenter (DTI) was 4.7 cm (range 0.2-10.5) in the SIMT group. Local recurrence-free interval was not associated with the distance to the isocenter in univariable or multivariable Cox-regression analysis. Multivariable analysis revealed only volume as an independent significant predictor for local failure (p-value <0.05).
SRS/SRT using single-isocenter VMAT for multiple targets achieved high local metastases control rates irrespective of distance to the isocenter, supporting efficacy of single-isocenter stereotactic radiation therapy for multiple brain metastases.
评估使用无框架直线加速器单等中心容积旋转调强弧形（VMAT）立体定向放射治疗（SRS）/立体定向放射治疗（SRT）治疗多个脑转移瘤时，治疗等中心与脑转移瘤之间的距离对局部失败的影响。
本回顾性研究纳入了 2014 年 4 月至 2019 年 5 月期间接受 SRT 治疗的脑转移瘤（BM）患者。对采用单等中心多靶区（SIMT）SRT 治疗的 BM 进行局部无复发生存期评估，根据其与治疗等中心的距离进行分析。采用 Cox 回归模型研究局部失败的不同预测变量。结果与采用单等中心单靶区（SIST）方法治疗的患者进行比较。
本研究共分析了 315 例患者的 1087 个 BM，其中 140 例患者和 708 个 BM 接受了 SIMT SRS/SRT 治疗。SIMT 组的中位随访时间为治疗后 13.9 个月，SIST 组为 11.9 个月。SIST 和 SIMT 组的 1 年局部无复发生存率分别为 87%和 94%。SIMT 组的等中心距离中位数（DTI）为 4.7cm（范围 0.2-10.5）。在单变量或多变量 Cox 回归分析中，局部无复发生存期与等中心距离无关。多变量分析显示，只有体积是局部失败的独立显著预测因素（p 值<0.05）。
使用单等中心 VMAT 进行多靶区 SRS/SRT 治疗，无论与等中心的距离如何，均可获得较高的局部转移瘤控制率，支持单等中心立体定向放射治疗多个脑转移瘤的疗效。
