Department of Neurosurgery, Koç University Hospital, Istanbul, Turkey.
Department of Radiation Oncology, Koç University Hospital, Istanbul, Turkey.
Clin Exp Metastasis. 2021 Jun;38(3):305-320. doi: 10.1007/s10585-021-10086-y. Epub 2021 Mar 17.
Stereotactic radiosurgery (SRS) has become a standard of care for the treatment of metastatic brain tumors (METs). Although a better balance of tumor control and toxicity of hypofractionated SRS (hfSRS) compared with single-fraction SRS (sfSRS) was demonstrated in large METs, there is no data comparing two approaches for small METs (< 4 cm). It was aimed to compare clinical outcomes between sfSRS versus hfSRS Gamma Knife radiosurgery (GKRS) in a series of patients with unresected, small METs. Patients (n = 208) treated with sfGKRS or hfGKRS between June 2017 and May 2020 were retrospectively examined in a single center. The co-primary endpoints of local control (LC) and toxicity were estimated by applying the Kaplan-Meier method. Multivariate analysis using Cox proportional hazards (HR) modeling was used to assess the effect of independent variables on the outcomes. The actuarial LC rate was 99.7% at six months and 98.8% at 18 months in the sfGKRS group, and 99.4% and 94.3% in the hfGKRS group (p = 0.089), respectively. In multivariate analysis, MET volume (p = 0.023, HR 2.064) and biologically effective dose (BED) (p < 0.0001, HR 0.753) was associated with LC. In total, treatment-related toxicity was observed in 13 (8.7%) patients during a median period of 10 weeks (range 1-31). Radiation necrosis was observed in four patients (1.9%), and all patients were in the sfGKRS group (p = 0.042). Only the maximum dose was associated with toxicity (p = 0.032, HR 1.047). Our current results suggest that hfGKRS is advantageous and beneficial also in patients with unresected, small METs.
立体定向放射外科（SRS）已成为治疗转移性脑肿瘤（METs）的标准治疗方法。尽管与单次分割 SRS（sfSRS）相比，分次 SRS（hfSRS）在大型 METs 中显示出更好的肿瘤控制和毒性平衡，但对于小 METs（<4cm），尚无比较两种方法的数据。本研究旨在比较未切除的小 METs 患者接受单次分割 SRS 与分次 SRS 伽玛刀放射外科（GKRS）治疗的临床结果。在一家单中心回顾性研究了 208 例于 2017 年 6 月至 2020 年 5 月接受 sfGKRS 或 hfGKRS 治疗的患者。采用 Kaplan-Meier 法估计局部控制（LC）和毒性的主要终点。采用 Cox 比例风险（HR）模型的多变量分析用于评估独立变量对结果的影响。在 sfGKRS 组，6 个月和 18 个月的累积 LC 率分别为 99.7%和 98.8%，hfGKRS 组分别为 99.4%和 94.3%（p=0.089）。多变量分析显示，MET 体积（p=0.023，HR 2.064）和生物有效剂量（BED）（p<0.0001，HR 0.753）与 LC 相关。在中位 10 周（1-31 周）的时间内，共有 13 例（8.7%）患者出现与治疗相关的毒性。4 例（1.9%）患者出现放射性坏死，均发生在 sfGKRS 组（p=0.042）。仅最大剂量与毒性相关（p=0.032，HR 1.047）。本研究结果表明，分次 GKRS 治疗未切除的小 METs 也是有利和有益的。
