Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

Chung, Wen‐Yuh; Liu, Kang-Du; Shiau, Chung‐Wai; Wu, Hsiu‐Mei; Wang, Ling-Wei; Guo, Wan‐Yuo; Ho, Donald Ming‐Tak; Pan, David Hung-Chi

doi:10.3171/jns.2005.102.s_supplement.0087

Cited by 108 publications

(61 citation statements)

References 23 publications

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“…4,[6][7][8][9][10][11][12][13][14]16,[22][23][24][25]30,32 Complications (deficit of CNs V and VII) are extremely rare. …”

Section: Neurosurg Focus 27 (6):e3 2009mentioning

confidence: 99%

Evaluation of hearing function after Gamma Knife surgery of vestibular schwannomas

Franzin¹,

Spatola²,

Serra³

et al. 2009

FOC

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Object Due to technological advances in neuroradiology in recent years, incidental diagnoses of vestibular schwannomas (VSs) have increased. The aim of this study was to evaluate the hearing function after treatment with Gamma Knife surgery (GKS) for VSs in patients adequately selected with “good” or “useful” hearing before treatment and to assess the possible predictive factors for hearing function preservation. Methods Of all patients treated in the authors' hospital between 2001 and 2007, they retrospectively studied 50 patients with a unilateral VS in whom there was serviceable hearing (Gardner-Robertson [GR] Class I or II). Additional inclusion criteria were: no Type 2 neurofibromatosis, no previous treatment, and at least 6 months' follow-up of neuroradiological and audiological data. The median patient age was 54 years (range 24–78 years). The median tumor volume was 0.73 ml (range 0.03–6.6 ml), and the median radiation dose to the tumor margin was 13 Gy (range 12–16 Gy) with an isodose of 50%. Results Patient age, tumor volume, and presenting symptoms were found to correlate with hearing function. At a median of 36 months after radiosurgery, tumor growth control was 96% and no patient required any other additional treatment. Serviceable hearing was preserved in 34 patients (68%): 21 (62%) with GR Class I hearing and 13 (38%) with GR Class II hearing. The remaining 16 patients had poor hearing function:15 with GR Class III and 1 with GR Class IV hearing function. In 19 (58%) of 33 patients with GR Class I function before GKS the same class was maintained posttreatment; 29 (88%) maintained functional hearing (GR Class I or II). In all patients with an intracanalicular lesion, functional hearing was maintained. Significant prognostic factors for maintaining serviceable hearing were GR Class I function before treatment, symptoms at presentation, patient age younger than 54 years, and Koos Stage T1 disease. Conclusions The results of the study show that the probability of preserving functional hearing in patients undergoing GKS treatment for unilateral VSs is very high. Patients with GR Class I, age younger than 54 years, with presenting symptoms other than hearing loss, and a Koos Stage T1 tumor have better prognosis. The prescribed dose of 13 Gy appears to represent an excellent compromise between controlling the disease and preserving auditory function.

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“…4,[6][7][8][9][10][11][12][13][14]16,[22][23][24][25]30,32 Complications (deficit of CNs V and VII) are extremely rare. …”

Section: Neurosurg Focus 27 (6):e3 2009mentioning

confidence: 99%

Evaluation of hearing function after Gamma Knife surgery of vestibular schwannomas

Franzin¹,

Spatola²,

Serra³

et al. 2009

FOC

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“…[14,16,17,23,27,30,[34][35][36][37][38][39][40][41]. Hydrocephalus, cerebral edema, and other cranial neuropathies have also been documented after GKRS, and in some reported cases required shunting as a treatment for hydrocephalus [4,23,37,[42][43][44][45][46][47][48][49].…”

Section: Introductionmentioning

confidence: 99%

Facial nerve preservation after vestibular schwannoma Gamma Knife radiosurgery

et al. 2009

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Objective 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. Materials and methods 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. Results 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 (B13 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 (B1.5 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. Conclusion 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.

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“…3,[25][26][27] Stereotactic radiosurgery (SRS), utilizing either a linac or GK-based system approach, is a noninvasive alternative to surgery, with comparable local control rates demonstrated. 9,[28][29][30][31] Due to the close proximity of most tumors to the brainstem, the risks of cranial nerve dysfunction secondary to marginal doses have resulted in initially higher complication rates with SRS, 29,30 although these have now decreased over recent years concomitant with reduction in the total dose prescribed, improved expertise, and better patient selection. 8,32,33 FSRT for AN remains a viable, radiotherapeutic alternative, achieving comparable local control rates to both microsurgery and SRS, and with comparable morbidity in modern series.…”

Section: Discussionmentioning

confidence: 99%

“…These excellent results compare very favorably not only with other FSRT series, 1,6,15 but also with other surgical and radiosurgical series. 8,9,35 However, controversy still exists regarding treatment selection in patients with serviceable hearing and minor functional nerve impairment. It remains challenging to perform a direct comparison of facial nerve preservation rates even among larger surgical series, as this is dependent on variables including tumor size, location, and surgical expertise.…”

Section: Discussionmentioning

confidence: 99%

“…3,4 Other treatment options for AN include fractionated stereotactic radiotherapy (FSRT) 1,5,6 and stereotactic radiosurgery-using both linear accelerator (linac) 7 and gamma knife (GK)-based approaches. 8,9 Alternatively, in selected cases a conservative management approach may be a desirable alternative. [10][11][12][13] FSRT has an advantage in that it combines the target and dose localization characteristics of the radiosurgical system with the radiobiologic advantages of fractionation.…”

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confidence: 99%

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Fractionated stereotactic radiotherapy for acoustic neuroma

Koh

Millar

Ménard

et al. 2007

Cancer

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BACKGROUND.The clinical outcome and toxicity of fractionated stereotactic radiotherapy (FSRT) was assessed for acoustic neuroma in 60 patients treated in a single institution.METHODS.Between October 1996 and February 2005, 60 patients received FSRT for acoustic neuroma (AN). The mean total dose applied was 50 Gy in single daily 2‐Gy fractions over 5 weeks. The median irradiated tumor volume was 4.9 cm3 (range, 0.3–49.0 cm3). The median follow‐up period was 31.9 months.RESULTS.FSRT was well tolerated in all patients. The 5‐year actuarial local control rate was 96.2% (95% CI: 91.1%–100.0%). Five‐year actuarial progression‐free survival was 92.8% (95% CI: 84.8%–100.0%). The overall hearing preservation rate was 77.3%. Five of 6 patients with initial cranial nerve V (CNV) numbness remained stable post‐FSRT. Two of 3 patients with baseline trigeminal neuralgia improved with the remaining patient stable. All 3 patients with nonsurgically related facial nerve weakness either improved or achieved stability in function. There were no cases of new cranial nerve toxicity post‐FSRT.CONCLUSIONS.FSRT for the treatment of AN is safe, effective, and well tolerated. FSRT should thus be considered as an effective alternative treatment modality when compared with microsurgical resection or single fraction stereotactic radiosurgery. Cancer 2007. © 2007 American Cancer Society.

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Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

Abstract: Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

Cited by 108 publications

References 23 publications

Evaluation of hearing function after Gamma Knife surgery of vestibular schwannomas

Evaluation of hearing function after Gamma Knife surgery of vestibular schwannomas

Facial nerve preservation after vestibular schwannoma Gamma Knife radiosurgery

Fractionated stereotactic radiotherapy for acoustic neuroma

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