Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland.
Neurosurgery. 2023 Jun 1;92(6):1216-1226. doi: 10.1227/neu.0000000000002352. Epub 2023 Jan 24.
Stereotactic radiosurgery has become a common treatment approach for small-to-medium size vestibular schwannomas.
To evaluate relationship between time (beam-on and treatment) and risk of hearing decline after stereotactic radiosurgery for vestibular schwannomas in patients with Gardner-Robertson (GR) baseline classes I and II.
This retrospective longitudinal single-center study included 213 patients with GR I and II treated between June 2010 and December 2019. Risk of passing from GR classes I and II (coded 0) to other classes III, IV, and V (coded 1) and the increase in pure tone average (continuous outcome) were evaluated using a mixed-effect regression model. Biologically effective dose (BED) was further assessed for an alpha/beta ratio of 2.47 (Gy 2.47 ).
Binary outcome analysis revealed sex, dose rate, integral dose, time [beam-on time odds ratio 1.03, P = .03, 95% CI 1.00-1.06; treatment time ( P = .02) and BED ( P = .001) as relevant. Fitted multivariable model included the sex, dose rate, and BED. Pure tone average analysis revealed age, integral dose received by tumor, isocenter number, time (beam-on time odds ratio 0.20, P = .001, 95% CI 0.083-0.33) and BED ( P = .005) as relevant.
Our analysis showed that risk of hearing decline was associated with male sex, higher radiation dose rate (cutoff 2.5 Gy/minute), higher integral dose received by the tumor, higher beam-on time ≥20 minutes, and lower BED. A BED between 55 and 61 was considered as optimal for hearing preservation.
立体定向放射外科已成为治疗中小体积前庭神经鞘瘤的常用方法。
评估 Gardner-Robertson（GR）基线 I 级和 II 级患者接受立体定向放射外科治疗前庭神经鞘瘤后，时间（照射时间和治疗时间）与听力下降风险之间的关系。
本回顾性纵向单中心研究纳入了 2010 年 6 月至 2019 年 12 月期间接受治疗的 213 例 GR I 级和 II 级患者。采用混合效应回归模型评估从 GR I 级和 II 级（编码为 0）转为其他级（III、IV 和 V，编码为 1）的风险以及纯音平均听力（连续结果）的变化。进一步评估了生物有效剂量（BED），α/β 比为 2.47（Gy 2.47 ）。
二元结果分析显示，性别、剂量率、积分剂量、时间[照射时间比值比 1.03，P =.03，95%置信区间 1.00-1.06；治疗时间（ P =.02）和 BED（ P =.001）是相关因素。拟合多变量模型包括性别、剂量率和 BED。纯音平均听力分析显示年龄、肿瘤接受的积分剂量、等中心点数量、时间（照射时间比值比 0.20，P =.001，95%置信区间 0.083-0.33）和 BED（ P =.005）是相关因素。
我们的分析表明，听力下降风险与男性性别、更高的放射剂量率（2.5 Gy/min 为临界值）、肿瘤接受的更高积分剂量、更长的照射时间（≥20 分钟）以及更低的 BED 相关。BED 在 55 到 61 之间被认为是听力保护的最佳选择。
