Galloway Luke, Palaniappan Nachi, Shone Geoffrey, Hayhurst Caroline
Cardiff Skull Base Centre, University Hospital of Wales, Cardiff, Wales, UK.
Department of Neurosurgery, University Hospital of Wales, Cardiff, Wales, CF14 4XW, UK.
Acta Neurochir (Wien). 2018 Apr;160(4):681-688. doi: 10.1007/s00701-017-3452-1. Epub 2018 Jan 17.
Trigeminal neuropathy (TGN) can occur as a presenting feature of vestibular schwannoma (VS) or as an adverse effect of radiosurgery. This study was designed to evaluate a treatment algorithm for presenting symptoms of TGN in patients with VS, and a new radiosurgery dosimetric tolerance to avoid TGN after treatment. Outcome was measured after microsurgery (MS), stereotactic radiosurgery (SRS), hypofractionated stereotactic radiotherapy (HSRT), and fractionated radiotherapy (FRT).
A prospectively held VS database was retrospectively analysed from 2011 to 2016 at a tertiary university hospital. All patients who underwent MS from 2011 and all patients who underwent radiotherapy (SRS, HSRT, FRT) from 2015 were studied. Patients on surveillance and neurofibromatosis type 2 patients were not included. Patient demographic data, tumour characteristics, presenting symptoms, and post-treatment outcomes were analysed.
Eighty-eight patients were included in the study (43 microsurgery, 45 radiotherapy). Twenty-seven (31%) patients presented with TGN symptoms. The median age of patients included was 56.5 (range 6-72 years), with a median follow-up for MS and SRS of 38 and 20 months, respectively (range 10-80 months). All 27 patients with TGN were offered MS as per protocol. Three patients declined, or were not fit for surgery, and received FRT. Complete resolution of TGN symptoms was achieved in all 24 patients who underwent MS and 33% (1/3) of patients with FRT. Eleven patients experienced transient post-operative complications (pseudomeningocele (6), meningitis (3), venous sinus thrombosis, cerebellar haemorrhagic contusion, and posterior fossa haematoma). Of the 45 patients in the radiotherapy cohort, 36 were suitable for SRS, of which 30 patients who met the dose-volume constraints for trigeminal nerve underwent single-fraction SRS and 6 patients who did not meet the constraints received HSRT. Nine patients (20%) received FRT including three patients with pre-treatment TGN. None of the patients developed new TGN symptoms following SRS or HSRT.
Our algorithm to select the optimal treatment modality appears to achieve comparable or better long-term outcome. Microsurgical resection in our cohort resulted in complete resolution of symptoms in all patients. None of our SRS- or HSRT-treated patients developed TGN during the follow-up period. The adherence to strict trigeminal nerve dose-volume constraints for SRS remains critical to minimise TGN post treatment. Fractionated radiotherapy is an alternative for patients who refuse surgery or those who are unfit for surgery.
三叉神经病变（TGN）可能是前庭神经鞘瘤（VS）的首发症状，也可能是放射外科手术的不良反应。本研究旨在评估一种针对VS患者TGN症状的治疗方案，以及一种新的放射外科剂量耐受性，以避免治疗后发生TGN。在接受显微手术（MS）、立体定向放射外科手术（SRS）、低分割立体定向放射治疗（HSRT）和分次放射治疗（FRT）后对结果进行测量。
对一所三级大学医院2011年至2016年前瞻性建立的VS数据库进行回顾性分析。研究了2011年接受MS的所有患者以及2015年接受放射治疗（SRS、HSRT、FRT）的所有患者。不包括接受观察治疗的患者和2型神经纤维瘤病患者。分析患者的人口统计学数据、肿瘤特征、首发症状和治疗后结果。
88例患者纳入研究（43例接受显微手术，45例接受放射治疗）。27例（31%）患者出现TGN症状。纳入患者的中位年龄为56.5岁（范围6 - 72岁），MS和SRS的中位随访时间分别为38个月和20个月（范围10 - 80个月）。所有27例TGN患者均按方案接受MS治疗。3例患者拒绝或不适合手术，接受了FRT。所有24例接受MS治疗的患者以及33%（1/3）接受FRT治疗的患者TGN症状完全缓解。11例患者经历了短暂的术后并发症（假性脑膜膨出（6例）、脑膜炎（3例）、静脉窦血栓形成、小脑出血性挫伤和后颅窝血肿）。在放射治疗队列的45例患者中，36例适合SRS，其中30例符合三叉神经剂量 - 体积限制的患者接受了单次分割SRS，6例不符合限制的患者接受了HSRT。9例患者（20%）接受了FRT，包括3例治疗前有TGN的患者。SRS或HSRT治疗后，无患者出现新的TGN症状。
我们选择最佳治疗方式的方案似乎能取得相当或更好的长期效果。我们队列中的显微手术切除使所有患者症状完全缓解。我们接受SRS或HSRT治疗的患者在随访期间均未发生TGN。严格遵守SRS的三叉神经剂量 - 体积限制对于减少治疗后TGN至关重要。分次放射治疗是拒绝手术或不适合手术患者的一种选择。
