Wade Louise, Boyce Hazel, Brown William J H, Clamp Philip J, Cameron Alison L
1Oncology Department, Royal United Hospitals Bath NHS Foundation Trust, Bath.
2Oncology Department, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol.
J Neurosurg. 2024 Nov 8;142(4):1134-1140. doi: 10.3171/2024.7.JNS24538. Print 2025 Apr 1.
The authors' objective was to validate dosimetric and clinical predictors of the development of trigeminal neuropathy (Tn) in patients treated with stereotactic radiosurgery (SRS) for a diagnosis of vestibular schwannoma (VS).
In total, 301 patients were treated with SRS for VS at the authors' center between April 2013 and June 2020, with a median prescription dose of 12.5 Gy. Ninety-seven patients were excluded: 78 had pre-existing symptoms of Tn, and 19 had < 2 years of follow-up. At follow-up consultations, trigeminal nerve function was prospectively documented in an institutional database. The median follow-up was 4 years. Data from treatment plans were extracted for factors previously reported as predictors of Tn: volume of cranial nerve (CN) V that received at least 11 Gy, maximum dose to CN V, volume of the cisternal portion of CN V, maximum dose to the brainstem, volume of the brainstem that received at least 12 Gy, and tumor volume. Tumor compression of CN V at baseline was also evaluated. Univariate and multivariate analyses of results were performed to identify significant factors.
In total, 23 (11.3%) patients developed symptoms of Tn after SRS; these symptoms were transitory in 7 (30%) cases. Of the 16 patients with permanent Tn, 13 had objective paresthesia (9 had grade II and 4 grade III) and 5 had pain (2 grade II and 3 grade III); included in this are 2 patients who had both paresthesia and pain. In addition, 44% developed symptoms by 1 year after SRS and 100% by 3 years after SRS. On univariate analysis of patients with permanent symptoms, maximum dose to CN V (p = 0.016) was a significant factor. This was not maintained on multivariate analysis when the volume of CN V that received ≥ 11 Gy became the only significant factor (p = 0.029).
The only significant factor in the risk of development of Tn after SRS for VS was the volume of CN V that received ≥ 11 Gy. This should be routinely incorporated into dosimetric planning constraints and patients should be counseled about the risk of adverse effects if it cannot be met. For those with growing VS and a gap to the trigeminal nerve, it may be prudent to provide earlier treatment with SRS to enable application of this dosimetric constraint and reduced risk of Tn.
作者的目的是验证接受立体定向放射外科治疗（SRS）以诊断前庭神经鞘瘤（VS）的患者发生三叉神经病变（Tn）的剂量学和临床预测因素。
2013年4月至2020年6月期间，作者所在中心共有301例患者接受了VS的SRS治疗，中位处方剂量为12.5 Gy。97例患者被排除：78例有Tn的既往症状，19例随访时间<2年。在随访会诊时，三叉神经功能被前瞻性记录在机构数据库中。中位随访时间为4年。从治疗计划中提取先前报告为Tn预测因素的数据：接受至少11 Gy照射的颅神经（CN）V体积、CN V的最大剂量、CN V脑池段体积、脑干的最大剂量、接受至少12 Gy照射的脑干体积以及肿瘤体积。还评估了基线时肿瘤对CN V的压迫情况。对结果进行单因素和多因素分析以确定显著因素。
总共23例（11.3%）患者在SRS后出现Tn症状；其中7例（30%）症状为暂时性。在16例永久性Tn患者中，13例有客观感觉异常（9例为II级，4例为III级），5例有疼痛（2例为II级，3例为III级）；其中包括2例既有感觉异常又有疼痛的患者。此外，44%的患者在SRS后1年内出现症状，100%在SRS后3年内出现症状。对有永久性症状的患者进行单因素分析时，CN V的最大剂量（p = 0.016）是一个显著因素。当接受≥11 Gy照射的CN V体积成为唯一显著因素（p = 0.029）时，多因素分析中该因素不再显著。
VS患者接受SRS后发生Tn风险的唯一显著因素是接受≥11 Gy照射的CN V体积。这应常规纳入剂量学计划限制中，如果无法满足该限制，应向患者告知不良反应风险。对于VS生长且与三叉神经有间隙的患者，谨慎起见，可尽早进行SRS治疗，以便应用该剂量学限制并降低Tn风险。
