Article

Facial nerve preservation after vestibular schwannoma Gamma Knife radiosurgery.

Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA 94143, USA.
Journal of Neuro-Oncology (Impact Factor: 3.12). 05/2009; 93(1):41-8. DOI: 10.1007/s11060-009-9842-3
Source: PubMed

ABSTRACT Facial nerve preservation is a critical measure of clinical outcome after vestibular schwannoma treatment. Gamma Knife radiosurgery has evolved into a practical treatment modality for vestibular schwannoma patients, with several reported series from a variety of centers. In this study, we report the results of an objective analysis of reported facial nerve outcomes after the treatment of vestibular schwannomas with Gamma Knife radiosurgery.
A Boolean Pub Med search of the English language literature revealed a total of 23 published studies reporting assessable and quantifiable outcome data regarding facial nerve function in 2,204 patients who were treated with Gamma Knife radiosurgery for vestibular schwannoma. Inclusion criteria for articles were: (1) Facial nerve preservation rates were reported specifically for vestibular schwannoma, (2) Facial nerve functional outcome was reported using the House-Brackmann classification (HBC) for facial nerve function, (3) Tumor size was documented, and (4) Gamma Knife radiosurgery was the only radiosurgical modality used in the report. The data were then aggregated and analyzed based on radiation doses delivered, tumor volume, and patient age.
An overall facial nerve preservation rate of 96.2% was found after Gamma Knife radiosurgery for vestibular schwannoma in our analysis. Patients receiving less than or equal to 13 Gy of radiation at the marginal dose had a better facial nerve preservation rate than those who received higher doses (<or=13 Gy = 98.5% vs. >13 Gy = 94.7%, P < 0.0001). Patients with a tumor volume less than or equal to 1.5 cm(3) also had a greater facial nerve preservation rate than patients with tumors greater than 1.5 cm(3) (<or=1.5 cm(3) 99.5% vs. >1.5 cm(3) 95.5%, P < 0.0001). Superior facial nerve preservation was also noted in patients younger than or equal to 60 years of age (96.8 vs. 89.4%, P < 0.0001). The average reported follow up duration in this systematic review was 54.1 +/- 31.3 months.
Our analysis of case series data aggregated from multiple centers suggests that a facial nerve preservation rate of 96.2% can be expected after Gamma knife radiosurgery for vestibular schwannoma. Younger patients with smaller tumors less than 1.5 cm(3) and treated with lower doses of radiation less than 13 Gy will likely have better facial nerve preservation rates after Gamma Knife radiosurgery for vestibular schwannoma.

1 Bookmark
 · 
255 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intracranial meningiomas and vestibular schwannomas (VS, aka acoustic neuromas) are typically benign, slow-growing, non-invasive neoplasms. The imaging and radiobiologic characteristics of these tumors make them good candidates for stereotactic radiosurgery (SRS), a technique that has been in use for over three decades. Patient selection is critical for successful SRS: small- to moderate-sized tumors can be effectively treated with SRS if the patient does not have symptoms related to mass effect. Factors related to tumor control in meningioma SRS include histology, history of prior surgery, and volume. Tumor control rates after SRS is significantly lower for patients with WHO grade II or III meningiomas compared to patients with WHO grade I meningiomas. The risk of radiation-related complications is higher for patients with larger tumors and tumors located over the convexities or along the falx. Patients with small-volume non-operated skull base or tentorial WHO grade I meningiomas typically have the best outcomes after SRS. Radiosurgery of sporadic VS provides a high tumor control rate (92-95 %), with less than a 5 % risk of facial weakness. Hearing preservation progressively declines for 10 years or more after SRS, and the primary factors related to long-term preservation of useful hearing are tumor size and pre-SRS hearing class. Radiosurgery remains an important option for patients with neurofibromatosis type 2, but tumor control is lower and the risk of cranial nerve deficits is greater when compared to patients with sporadic VS.
    Current Treatment Options in Neurology 08/2014; 16(8):308. · 1.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Trigeminal neuralgia (TGN) occurring after radiosurgical treatment of cerebellopontine or petroclival tumors may be very difficult to control. Our aim was to determine the efficacy of neurosurgical treatment in regards to pain control and to evaluate the procedure-related complication and morbidity rates.
    Clinical neurology and neurosurgery. 07/2014; 122C:23-28.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The classical surgical technique for the resection of vestibular schwannomas (VS) has emphasized the microsurgical anatomy of cranial nerves. We believe that the focus on preservation of the arachnoid membrane may serve as a safe guide for tumor removal. Method The extracisternal approach is described in detail. We reviewed charts from 120 patients treated with this technique between 2006 and 2012. Surgical results were evaluated based on the extension of resection, tumor relapse, and facial nerve function. Results Overall gross total resection was achieved in 81% of the patients. The overall postoperative facial nerve function House-Brackmann grades I-II at one year was 93%. There was no recurrence in 4.2 years mean follow up. Conclusion The extracisternal technique differs from other surgical descriptions on the treatment of VS by not requiring the identification of the facial nerve, as long as we preserve the arachnoid envelope in the total circumference of the tumor.
    Arquivos de neuro-psiquiatria. 12/2014;

Full-text (2 Sources)

Download
9 Downloads
Available from
Sep 25, 2014