Department of Neurological Surgery, University of Virginia, Charlottesville , Virginia , USA.
Department of Neurological Surgery, Hospices civils de Lyon, Lyon , France.
Neurosurgery. 2024 Mar 1;94(3):614-621. doi: 10.1227/neu.0000000000002717. Epub 2023 Oct 13.
Stereotactic radiosurgery (SRS) represents an effective treatment for pediatric arteriovenous malformations (AVMs). Biological effective dose (BED) has shown promising results in 2 previous studies as a predictive variable for outcomes in adults, but its role has never been studied in pediatric outcomes.
Retrospective data for patients 18 years or younger treated with a single-session SRS for AVMs were collected from 1989 to 2019. BED calculations were performed using an α/β ratio of 2.47. Kaplan-Meier analysis was used to evaluate obliteration, new hemorrhage, and radiation-induced changes (RIC). Cox-regression analysis was used for obliteration prediction using 2 models (margin dose vs BED).
One hundred ninety-seven patients (median age = 13.1 years, IQR = 5.2) were included; 72.6% (143/197) of them presented initially with spontaneous hemorrhage. A median margin dose of 22 Gy (IQR = 4.0) with a median BED of 183.2 Gy (IQR = 70.54) was used to treat AVM with a median volume of 2.8 cm 3 (IQR = 2.9). After SRS, obliteration was confirmed in 115/197 patients (58.4%) using magnetic resonance imaging and angiography at a median follow-up of 2.85 years (IQR = 2.26). The cumulative obliteration probability was 43.6% (95% CI = 36.1-50.3), 60.5% (95% CI+ = 2.2-67.4), and 66.0% (95% CI = 56.0-73.7) at 3, 5, and 10 years, respectively. In Cox multivariate analysis, a BED >180 Gy (hazard ratio [HR] = 2.11, 95% CI = 1.30-3.40, P = .002) in model 1 and a margin dose >20 Gy (HR = 1.90, 95% CI = 1.15-3.13, P = .019) in model 2 were associated with obliteration. An AVM nidus volume >4 cm 3 was associated with lower obliteration rates in both models. The probability of symptomatic RIC at 10 years was 8.6% (95% CI = 3.5-13.4). Neither BED nor margin dose was associated with RIC occurrence, with the only predictive factor being deep AVM location (HR = 3, 95% CI = 1-9.1, P = .048).
This study confirms BED as a predictor for pediatric AVM obliteration. Optimization of BED in pediatric AVM SRS planning may improve cumulative obliteration rates.
立体定向放射外科（SRS）是治疗小儿动静脉畸形（AVM）的有效方法。生物有效剂量（BED）在之前的两项研究中作为成人治疗结果的预测变量显示出良好的效果，但在小儿治疗结果中尚未进行研究。
收集了 1989 年至 2019 年间接受单次 SRS 治疗的 18 岁以下 AVM 患者的回顾性数据。BED 计算使用α/β 比值为 2.47。采用 Kaplan-Meier 分析评估闭塞、新出血和放射性改变（RIC）。采用 Cox 回归分析两种模型（边缘剂量与 BED）对闭塞的预测。
共纳入 197 例患者（中位年龄 13.1 岁，IQR=5.2）；72.6%（143/197）的患者最初表现为自发性出血。使用中位边缘剂量 22 Gy（IQR=4.0）和中位 BED 183.2 Gy（IQR=70.54）治疗中位体积为 2.8 cm3（IQR=2.9）的 AVM。SRS 后，中位随访 2.85 年（IQR=2.26）时，197 例患者中有 115 例（58.4%）经磁共振成像和血管造影证实闭塞。累积闭塞概率分别为 43.6%（95%CI=36.1-50.3）、60.5%（95%CI+=2.2-67.4）和 66.0%（95%CI=56.0-73.7），分别为 3 年、5 年和 10 年。在 Cox 多变量分析中，模型 1 中 BED＞180 Gy（危险比[HR]=2.11，95%CI=1.30-3.40，P=0.002）和模型 2 中边缘剂量＞20 Gy（HR=1.90，95%CI=1.15-3.13，P=0.019）与闭塞有关。AVM 核体积＞4 cm3 与两个模型中的闭塞率降低有关。10 年后症状性 RIC 的概率为 8.6%（95%CI=3.5-13.4）。BED 和边缘剂量均与 RIC 的发生无关，唯一的预测因素是深部 AVM 位置（HR=3，95%CI=1-9.1，P=0.048）。
本研究证实 BED 可作为小儿 AVM 闭塞的预测因子。在小儿 AVM SRS 计划中优化 BED 可能会提高累积闭塞率。
