Department of Neurosurgery, Hospital Clínico Universitario de Valencia, Valencia, Spain; Microneurosurgery Laboratory, Department of Anatomy and Human Embryology, Universitat de Valencia, Valencia, Spain.
Department of Neurosurgery, Hospital Clínico Universitario de Valencia, Valencia, Spain; Microneurosurgery Laboratory, Department of Anatomy and Human Embryology, Universitat de Valencia, Valencia, Spain; INCLIVA Instituto de Investigación Sanitaria, Valencia, Spain.
World Neurosurg. 2020 Jul;139:e585-e591. doi: 10.1016/j.wneu.2020.04.073. Epub 2020 May 1.
Vestibular schwannoma (VS) is a benign, usually slow-growing tumor. The drawback of radical microsurgical VS resection is the increased likelihood of neurologic injury, forcing surgeons to leave a tumor remnant in some cases. We evaluated the prognostic value of magnetic resonance imaging (MRI) enhancement patterns to determine the risk of tumor regrowth.
This clinical study included 30 patients (20 women and 10 men) with VS who underwent surgery via a retrosigmoid transmeatal approach. The extent of resection was assessed by MRI 6 months after surgery. Two subtypes of intracanalicular linear enhancement were defined: linear enhancement of the walls of the internal auditory canal (IAC) or in the cerebellopontine angle (CPA) and linear enhancement covering the end of the IAC. All patients included in the study underwent follow-up MRI every year for at least 6 years.
Intracanalicular nodular enhancement suggestive of a tumor remnant was seen in the IAC in 11 patients (36.7%). Volume of nodular enhancements was <0.5 cm when measurable. The enhancement remained stable throughout follow-up except in 2 cases that showed a slight decrease in size and in 1 case with an initial tumor remnant of 0.5 cm showing a slight increase over the years. Eighteen patients (60%) had linear enhancement in the IAC or in the CPA. No patients with linear enhancement showed nodular enhancement.
Although specific monitoring protocols can be designed based on MRI findings 6 months after microsurgical VS resection, follow-up should be maintained indefinitely given the slight possibility of very late regrowth.
前庭神经鞘瘤（VS）是一种良性、生长缓慢的肿瘤。根治性显微手术切除 VS 的缺点是增加了神经损伤的可能性，迫使外科医生在某些情况下留下肿瘤残余。我们评估了磁共振成像（MRI）增强模式的预后价值，以确定肿瘤复发的风险。
本临床研究纳入了 30 名接受经乙状窦后经迷路入路手术的 VS 患者（20 名女性和 10 名男性）。术后 6 个月通过 MRI 评估切除程度。定义了两种类型的管内线性增强：内听道（IAC）壁或桥小脑角（CPA）的线性增强和覆盖 IAC 末端的线性增强。所有纳入研究的患者均在术后每年至少进行 6 年的 MRI 随访。
11 名患者（36.7%）的 IAC 中可见提示肿瘤残余的管内结节性增强。当可测量时，结节性增强的体积<0.5cm。除 2 例体积略有缩小和 1 例初始肿瘤残余为 0.5cm 的患者在数年内略有增加外，增强在整个随访过程中保持稳定。18 名患者（60%）的 IAC 或 CPA 有线性增强。没有线性增强的患者有结节性增强。
尽管可以根据显微外科 VS 切除术后 6 个月的 MRI 结果设计具体的监测方案，但鉴于非常晚期复发的可能性较小，应无限期地进行随访。
