Non-audiofacial morbidity after Gamma Knife surgery for vestibular schwannoma

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Object

While many studies have been published outlining morbidity following radiosurgical treatment of vestibular schwannomas, significant interpractitioner and institutional variability still exists. For this reason, the authors conducted a systematic review of the literature for non-audiofacial-related morbidity after the treatment of vestibular schwannoma with radiosurgery.

Methods

The authors performed a comprehensive search of the English-language literature to identify studies that published outcome data of patients undergoing radiosurgery treatment for vestibular schwannomas. In total, 254 articles were found that described more than 50,000 patients and were analyzed for satisfying the authors' inclusion criteria. Patients from these studies were then separated into 2 cohorts based on the marginal dose of radiation: ≤ 13 Gy and > 13 Gy. All tumors included in this study were < 25 mm in their largest diameter.

Results

A total of 63 articles met the criteria of the established search protocol, which combined for a total of 5631 patients. Patients receiving > 13 Gy were significantly more likely to develop trigeminal nerve neuropathy than those receiving < 13 Gy (p < 0.001). While we found no relationship between radiation dose and the rate of developing hydrocephalus (0.6% for both cohorts), patients with hydrocephalus who received doses > 13 Gy appeared to have a higher rate of symptomatic hydrocephalus requiring shunt treatment (96% [> 13 Gy] vs 56% [≤ 13 Gy], p < 0.001). The rates of vertigo or balance disturbance (1.1% [> 13 Gy] vs 1.8% [≤ 13 Gy], p = 0.001) and tinnitus (0.1% [> 13 Gy] vs 0.7% [≤ 13 Gy], p = 0.001) were significantly higher in the lower dose cohort than those in the higher dose cohort.

Conclusions

The results of our review of the literature provide a systematic summary of the published rates of nonaudiofacial morbidity following radiosurgery for vestibular schwannoma.

Abbreviations used in this paper: CN = cranial nerve; GKS = Gamma Knife surgery.

Object

While many studies have been published outlining morbidity following radiosurgical treatment of vestibular schwannomas, significant interpractitioner and institutional variability still exists. For this reason, the authors conducted a systematic review of the literature for non-audiofacial-related morbidity after the treatment of vestibular schwannoma with radiosurgery.

Methods

The authors performed a comprehensive search of the English-language literature to identify studies that published outcome data of patients undergoing radiosurgery treatment for vestibular schwannomas. In total, 254 articles were found that described more than 50,000 patients and were analyzed for satisfying the authors' inclusion criteria. Patients from these studies were then separated into 2 cohorts based on the marginal dose of radiation: ≤ 13 Gy and > 13 Gy. All tumors included in this study were < 25 mm in their largest diameter.

Results

A total of 63 articles met the criteria of the established search protocol, which combined for a total of 5631 patients. Patients receiving > 13 Gy were significantly more likely to develop trigeminal nerve neuropathy than those receiving < 13 Gy (p < 0.001). While we found no relationship between radiation dose and the rate of developing hydrocephalus (0.6% for both cohorts), patients with hydrocephalus who received doses > 13 Gy appeared to have a higher rate of symptomatic hydrocephalus requiring shunt treatment (96% [> 13 Gy] vs 56% [≤ 13 Gy], p < 0.001). The rates of vertigo or balance disturbance (1.1% [> 13 Gy] vs 1.8% [≤ 13 Gy], p = 0.001) and tinnitus (0.1% [> 13 Gy] vs 0.7% [≤ 13 Gy], p = 0.001) were significantly higher in the lower dose cohort than those in the higher dose cohort.

Conclusions

The results of our review of the literature provide a systematic summary of the published rates of nonaudiofacial morbidity following radiosurgery for vestibular schwannoma.

Abbreviations used in this paper: CN = cranial nerve; GKS = Gamma Knife surgery.

Since the first reported case in 1971 of a patient with vestibular schwannoma who was treated using radiosurgery by Leksell,34 GKS for the treatment of vestibular schwannoma has rapidly established itself as a viable alternative to microsurgical resection.7,28,29,32,47,53,57,61,77 Because GKS rarely requires hospitalization, is relatively noninvasive, and requires minimal recovery time, it may seem the ideal method of treatment. However, it is not without risk. Radiosurgery for the treatment of vestibular schwannoma introduces risks to the facial nerve and hearing, as well as posttreatment complications such as balance disturbances, hydrocephalus, headaches, tinnitus, and other cranial neuropathies.17,49

A large volume of literature has been published to date describing the postradiation morbidity and mortality in patients with vestibular schwannoma. However, given that most of these studies are small- to modest-sized case series, frequently from single institutions, it may be difficult for the new individual practitioner to use those studies to develop his/her own approach to the management of these tumors.

For this reason, we report a comprehensive review of the English-language literature to evaluate and present results on morbidity and mortality in patients treated via GKS for vestibular schwannoma. Through this, we aim to provide a representation of the effect of dose on the overall rates of morbidity for patients undergoing GKS for vestibular schwannoma.

Methods

Article Selection

A comprehensive review of the literature was conducted on the morbidity and mortality of patients who were treated using GKS for vestibular schwannoma by pooling data from the existing English-language literature. Articles were identified via a PubMed search using Boolean searches with the key words “Gamma Knife,” “vestibular schwannoma radiosurgery AND morbidity,” “vestibular schwannoma radiosurgery AND mortality,” “acoustic neuroma radiosurgery AND morbidity,” and “Gamma Knife surgery AND mortality” alone and in combination. After reviewing these articles, we then reviewed all references in these papers. This search was performed multiple times, most recently on May 31, 2007 (Table 1).

TABLE 1:

A summary of studies included in our analysis*

Authors & YearPub-Med IDSample SizeDose (Gy)
FractionatedMarginalMax
Hirsch et al., 19793867059noNA50
Hirsch & Norén, 19883051887111no21.537.5
Kamerer et al., 19883059942110noNA50
Thomsen et al., 199022401751noNA26
Linskey et al., 1992143640717no1833.3
Oyama et al., 1994752625113noNA28.7
Foote et al., 1995760793736no18NA
Ogunrinde et al., 1995782627931noNA32.8
Pollock et al., 1995770816278no16.331.2
Hirato et al., 1995853212928no12.125.2
Kondziolka et al., 199817112219462no15NA
Miller et al., 19991003025482no18NA
Niranjan et al., 19991051546829no14NA
Schulder et al., 1999103379791no14NA
Spiegelmann et al., 19991137013444no14NA
Subach et al., 19991022344540noNA29.4
Unger et al., 19991067229856no13NA
Ito et al., 200010924974125no15.429.8
Shirato et al., 20001112163965yes3650
Tago et al., 2000111432681no1420
Roos et al., 20001084998223no1220
Prasad et al., 200010794287153no13.334.3
Kida et al., 20001082552520no1326.8
Foote et al., 200111565866149no14NA
Shamisa et al., 2001113544161noNA27.5
Petit et al., 20011184692847no1224
Flickinger et al., 200111147876190no1326
Bertalanffy et al., 20011153468940no12NA
Karpinos et al., 20021245936475no14.5NA
Régis et al., 200212450031104no13NA
Rowe et al., 20031293393896no15.2NA
Watanabe et al., 2003146091741no24NA
Rowe et al., 200314617712234no13NA
Linskey et al., 20031269140554no12NA
Iwai et al., 20031292524251no12NA
Flickinger et al., 200415337560313no1326
Wackym et al., 20041535400729noNA27.4
Wowra et al., 200415707030111no13NA
Chung et al., 20041523404672no1321.9
Combs et al., 200516111574106yesNA 57.6
Hasegawa et al., 20051565809073no14.628.4
Hayhurst et al., 2005161205232noNANA
Poetker et al., 20051627294623noNA27.47
Wowra et al., 200515662792111noNA31.1
Wang et al., 2005156971667no1225.4
van Eck et al., 20051566281178no1320
Paek et al., 20051595220025no12NA
Myrseth et al., 200515854240103no12.235.3
Lunsford et al., 200515662809829no13NA
Inoue, 20051566279118no12NA
Huang et al., 20051603837145no11.523
Hasegawa et al., 200516094154317no13.226.2
Chung et al., 200515662787195no1321.9
Pollock, 200616462477208no13.527
Park et al., 2006163977528no12NA
Massager et al., 20061645844682no12NA
Hempel et al., 200616741754123no1322.7
Combs et al., 20061646453726no13NA
Koh et al., 20071731881760yesNA50
Mathieu et al., 20071732779062no1427.5
Neuhaus et al., 2007173100281noNA26
Rutten et al., 20071718214226no14NA
Franco-Vidal et al., 2007171594931no13NA
* All patients underwent GKS. Abbreviations: ID = identification; NA = not available.

Inclusion criteria for articles were that morbidity and/ or complication rates were reported specifically for GKS without other radiotherapy or radiosurgery modalities mixed in an aggregated fashion. Patients with neurofibromatosis Type 2 were also included. Studies of patients who underwent microsurgery as a definitive treatment or those that described other forms of radiation were excluded.

Data Extraction

Data from individual and aggregated cases were extracted from each paper as follows. For those studies that did not specifically state the morbidity rate, the complication rate was used. Facial nerve and hearing morbidities are not included in this study, but are reported in separate studies in our series.

Data were analyzed as a whole and stratified into 2 cohorts according to the mean marginal dose of radiation delivered: ≤ 13 Gy and > 13 Gy. The morbidities recorded in this review were all new morbidities, appearing after radiation treatment or exacerbations of symptoms present prior to radiosurgery. Short-term morbidities were those that lasted less than 3 months. All other morbidities were considered to be long term. Mortality was defined as death after GKS within 30 days of treatment.

All tumors included in this study were < 25 mm in their largest diameter. The median largest dimension and median tumor volume were not reportable as studies did not consistently report either value.

Statistical Analysis

The Pearson chi-square test was used for statistical evaluation of the data. The p value was considered significant at the 5% (0.05) level, after correcting for multiple comparisons with Bonferroni correction, using the 2-sided reading in each case.

Results

A total of 63 articles2–6,8–12,15–25,27,28,30,31,33,35,37–40,42,44–46,48,50–52,54,56,58–67,69,72–76,78,80–82,85,86 describing 5631 patients provided some useable data and were included in estimates of overall incidence of these complications. A large number of articles represented repeat publications from the same investigators on the same patient cohort discussing other aspects of that cohort. When this conflict arose, we excluded all obviously duplicated cohorts except the largest published cohort from that institution, or the most recent, which we assumed would include all previously published patients from this group. Other excluded articles had to be eliminated from the analysis for reasons of missing data or unusable data presentation.

Of these patients, 3248 received a mean marginal radiation dose ≤ 13 Gy, while 2383 patients (42%) received > 13 Gy. The median follow-up time for the group receiving ≤ 13 Gy was 39.5 months, and the median follow-up time for the group receiving > 13 Gy was 36.5 months.

Cranial Nerve Neuropathy

Following radiosurgery, 135 patients (2.4%) were reported to have developed a new non-CN VII or non-CN VIII cranial neuropathy. The rate of neuropathies of individual CNs are summarized in Table 2. Trigeminal neuropathy, manifested by facial paresthesias or tingling, was by far the most common neuropathy, occurring over 28 times more frequently than the next most common neuropathy. Patients receiving > 13 Gy were significantly more likely to develop trigeminal nerve neuropathy than those receiving < 13 Gy (p < 0.001) (Table 2).

TABLE 2:

A summary of rates of various CN neuropathies in the reported literature*

CN%p Value
Overall>13 Gy<13 Gy
I0.00.00.0NS
II0.00.00.0NS
III0.00.00.0NS
IV0.00.00.0NS
V2.303.151.63<0.001
VI0.030.080.0NS
IX0.00.00.0NS
X0.00.00.0NS
XI0.00.00.0NS
XII0.080.00.15NS
* NS = not significant.

Hydrocephalus

Hydrocephalus was reported in 48 patients (0.85%). Of these patients 36 (75%) required a shunt as the definitive form of treatment, and 12 patients (25%) were treated conservatively. Hydrocephalus was reported to have occurred in 24 (0.74%) of the 3248 patients receiving ≤ 13 Gy and in 24 (1.0%) of the 2383 patients receiving > 13 Gy. The reported incidence of hydrocephalus was not affected by marginal doses of radiation delivered to these patients (0.6% for both cohorts) (Fig. 1). However, patients with hydrocephalus who were receiving > 13 Gy appeared to have a higher rate of symptomatic hydrocephalus requiring shunt treatment than those receiving lower doses (96% [> 13 Gy] vs 56% [≤ 13 Gy], p < 0.001).

Fig. 1.
Fig. 1.

Bar graph showing a comparison of rates of hydrocephalus and symptomatic hydrocephalus between patients receiving > 13 Gy marginal radiation dose and those receiving ≤ 13 Gy. *p > 0.001.

Vertigo and Tinnitus

Eighty-four patients were reported to have experienced vertigo or balance disturbance after their treatment. In the group of 2383 patients that received marginal doses > 13 Gy, vertigo or balance disturbance occurred in 26 (1.1%). Of the 3248 patients in the group that was subjected to ≤ 13 Gy as their marginal dose of radiation, 58 (1.8%) were reported to have developed vertigo or balance disturbance. The rate of vertigo or balance disturbance in the lower-dose cohort was significantly higher than that in the higher-dose cohort (p = 0.001) (Fig. 2).

Fig. 2.
Fig. 2.

Bar graph showing a comparison of rates of vertigo and balance disturbance and tinnitus between patients receiving > 13 Gy marginal radiation dose and those receiving ≤ 13 Gy. *p > 0.001.

Twenty-five patients were reported to have tinnitus after treatment. In the group of 2383 patients that received marginal doses > 13 Gy, tinnitus occurred in 2 (0.1%). Of the 3248 patients in the group that was subjected to ≤ 13 Gy as their marginal dose of radiation, 23 patients (0.7%) reported tinnitus. The rate of tinnitus in the lower-dose cohort was significantly higher than that in the higher-dose cohort (0.1% [> 13 Gy] vs ≤ 13 Gy 0.7%, p = 0.001) (Fig. 2).

Discussion

Although the morbidity and mortality rates in patients undergoing radiosurgery for vestibular schwannoma have seen drastic improvements over the years, there has been wide variation in the published literature, with tumor control rates ranging from 60 to 100%.30,36 Due to the rarity of certain morbidities, it has been hard for smaller studies to provide accurate information regarding rates of occurrence. A large number of investigators have published their results previously, but to date there have been few attempts to systematically summarize the literature about this topic. In this study, we performed a comprehensive review of the literature of the morbidity and mortality in a large population of patients with vestibular schwannomas who were treated via single-fraction GKS.

Our analysis revealed that patients treated with an average marginal dose of 13 Gy or less were less likely to develop symptomatic trigeminal neuropathy over the time period of reported follow-up, when compared with those who received higher doses of radiation. Furthermore, while there was no statistically significant difference in the incidence of hydrocephalus between those patients who received a mean marginal radiation dose of 13 Gy or less and those that received a higher dose, patients receiving the higher dose seemed to have more severe hydrocephalus and usually required a CSF diversion procedure.

Interestingly, we found that patients treated with lower marginal doses experienced a small, but significantly increased rate of vertigo and balance problems, as well as an increase in the rate of posttreatment tinnitus. The reason for this is unclear, but we hypothesize that perhaps patients treated with higher doses have more complete dysfunction of this nerve, while those treated with lower doses have enough function left to detect vertigo or tinnitus. This may result from more severe involvement of the vestibular nerve with higher doses. Other reviews of the radiosurgery literature found that increased marginal doses lead to higher rates of posttreatment CN VIII dysfunction.87 Further work is needed to address this complex question.

More recently, fractionated radiosurgery has been used in an attempt to minimize injury to adjacent normal CNs using a linear accelerator or the CyberKnife (Accuray Systems).1,13,14,26,41,55,71,79,83,84 While planning is often similar to GKS, the method of immobilization is different. Rather than a frame-based approach, the position of target structure is replicated daily using customized head molds and/or face masks while obtaining regular radiographs to confirm positioning. While some consider the degree of accuracy less with these methods than that with frame-based techniques, there is evidence that results can be comparable if done properly.43,68,70 Further study is needed to assess whether fractionated radiotherapy has reduced morbidity when compared with radiosurgery.

There are several limitations with our study that should be acknowledged. Most notably, our analysis is inherently limited by the quality and accuracy of the reported literature, and unpublished data, which cannot be included in an analysis of this type, might reveal different results than an analysis limited to published data. Additionally, given the importance of long-term follow-up in studies of radiosurgery, it is not uncommon for investigators to follow up a cohort for a long period of time and to publish serial reports about the outcomes of these same patients. While we made every effort to exclude duplicated patients, it is possible that in our effort to exclude these patients, some of the smaller, earlier reports from some groups included unique patients not included in later cohorts and, thus, were incorrectly excluded from our analysis. Without the primary data sets, we cannot determine if this occurred and correct for it. Similarly, because we do not have the treatment plans for these patients, we can only look at marginal dose and are not able to assess the dose delivered to important structures such as the cochlea and the vestibular apparatus. Thus, the effect of lower dose could, in part, be the result of improved conformality of treatment plans in recent years, when lower doses were used more frequently.

Conclusions

We report our results from a large aggregated review of the English-language literature regarding radiosurgery for vestibular schwannoma. We hope that by using such a large data set, we are able to minimize the effect of individual institutions' bias to determine accurate outcome characteristics, specifically morbidity and mortality, for patients treated with radiosurgery to help physicians and patients determine the best approach for managing these tumors.

Disclosure

Dr. Sughrue was supported in part by a grant from the AANS Neurosurgery Research and Education Foundation (NREF). Dr. Yang was supported in part by the NIH National Research Service Award (NRSA) program. Dr. Kane was supported in part by a grant from the Howard Hughes Medical Institute. Dr. Parsa was supported by the Georgiana and Reza Khatib endowed chair for skull base tumor surgery.

References

  • 1

    Andrews DWSilverman CLGlass JDownes BRiley RJCorn BW: Preservation of cranial nerve function after treatment of acoustic neurinomas with fractionated stereotactic radiotherapy. Preliminary observations in 26 patients. Stereotact Funct Neurosurg 64:1651821995

    • Search Google Scholar
    • Export Citation
  • 2

    Bertalanffy ADietrich WAichholzer MBrix RErtl AHeimberger K: Gamma knife radiosurgery of acoustic neurinomas. Acta Neurochir (Wien) 143:6896952001

    • Search Google Scholar
    • Export Citation
  • 3

    Chung HTMa RToyota BClark BRobar JMcKenzie M: Audiologic and treatment outcomes after linear acceleratorbased stereotactic irradiation for acoustic neuroma. Int J Radiat Oncol Biol Phys 59:111611212004

    • Search Google Scholar
    • Export Citation
  • 4

    Chung WYLiu KDShiau CYWu HMWang LWGuo WY: Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases. J Neurosurg 102:Suppl87962005

    • Search Google Scholar
    • Export Citation
  • 5

    Combs SEThilmann CDebus JSchulz-Ertner D: Long-term outcome of stereotactic radiosurgery (SRS) in patients with acoustic neuromas. Int J Radiat Oncol Biol Phys 64:134113472006

    • Search Google Scholar
    • Export Citation
  • 6

    Combs SEVolk SSchulz-Ertner DHuber PEThilmann CDebus J: Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): long-term results in 106 patients treated in a single institution. Int J Radiat Oncol Biol Phys 63:75812005

    • Search Google Scholar
    • Export Citation
  • 7

    Delbrouck CHassid SMassager NChoufani GDavid PDevriendt D: Preservation of hearing in vestibular schwannomas treated by radiosurgery using Leksell Gamma Knife: preliminary report of a prospective Belgian clinical study. Acta Otorhinolaryngol Belg 57:1972042003

    • Search Google Scholar
    • Export Citation
  • 8

    Flickinger JCKondziolka DNiranjan ALunsford LD: Results of acoustic neuroma radiosurgery: an analysis of 5 years' experience using current methods. J Neurosurg 94:162001

    • Search Google Scholar
    • Export Citation
  • 9

    Flickinger JCKondziolka DNiranjan AMaitz AVoynov GLunsford LD: Acoustic neuroma radiosurgery with marginal tumor doses of 12 to 13 Gy. Int J Radiat Oncol Biol Phys 60:2252302004

    • Search Google Scholar
    • Export Citation
  • 10

    Foote KDFriedman WABuatti JMMeeks SLBova FJKubilis PS: Analysis of risk factors associated with radiosurgery for vestibular schwannoma. J Neurosurg 95:4404492001

    • Search Google Scholar
    • Export Citation
  • 11

    Foote RLCoffey RJSwanson JWHarner SGBeatty CWKline RW: Stereotactic radiosurgery using the gamma knife for acoustic neuromas. Int J Radiat Oncol Biol Phys 32:115311601995

    • Search Google Scholar
    • Export Citation
  • 12

    Franco-Vidal VSongu MBlanchet HBarreau XDarrouzet V: Intracochlear hemorrhage after gamma knife radiosurgery. Otol Neurotol 28:2402442007

    • Search Google Scholar
    • Export Citation
  • 13

    Fuss MDebus JLohr FHuber PRhein BEngenhart-Cabillic R: Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Int J Radiat Oncol Biol Phys 48:138113872000

    • Search Google Scholar
    • Export Citation
  • 14

    Fuss MSalter BJSadeghi AVollmer DGHevezi JMHerman TS: Fractionated stereotactic intensity-modulated radiotherapy (FS-IMRT) for small acoustic neuromas. Med Dosim 27:1471542002

    • Search Google Scholar
    • Export Citation
  • 15

    Hasegawa TFujitani SKatsumata SKida YYoshimoto MKoike J: Stereotactic radiosurgery for vestibular schwannomas: analysis of 317 patients followed more than 5 years. Neurosurgery 57:2572652005

    • Search Google Scholar
    • Export Citation
  • 16

    Hasegawa TKida YKobayashi TYoshimoto MMori YYoshida J: Long-term outcomes in patients with vestibular schwannomas treated using gamma knife surgery: 10-year follow up. J Neurosurg 102:10162005

    • Search Google Scholar
    • Export Citation
  • 17

    Hayhurst CDhir JDias PS: Stereotactic radiosurgery and vestibular schwannoma: hydrocephalus associated with the development of a secondary arachnoid cyst: a report of two cases and review of the literature. Br J Neurosurg 19:1781812005

    • Search Google Scholar
    • Export Citation
  • 18

    Hempel JMHempel EWowra BSchichor ChMuacevic ARiederer A: Functional outcome after gamma knife treatment in vestibular schwannoma. Eur Arch Otorhinolaryngol 263:7147182006

    • Search Google Scholar
    • Export Citation
  • 19

    Hirato MInoue HNakamura MOhye CHirato JShibazaki T: Gamma knife radiosurgery for acoustic schwannoma: early effects and preservation of hearing. Neurol Med Chir (Tokyo) 35:7377411995

    • Search Google Scholar
    • Export Citation
  • 20

    Hirsch ANorén G: Audiological findings after stereotactic radiosurgery in acoustic neurinomas. Acta Otolaryngol 106:2442511988

  • 21

    Hirsch ANorén GAnderson H: Audiologic findings after stereotactic radiosurgery in nine cases of acoustic neurinomas. Acta Otolaryngol 88:1551601979

    • Search Google Scholar
    • Export Citation
  • 22

    Huang CFTu HTLo HKWang KLLiu WS: Radiosurgery for vestibular schwannomas. J Chin Med Assoc 68:3153202005

  • 23

    Inoue HK: Low-dose radiosurgery for large vestibular schwannomas: long-term results of functional preservation. J Neurosurg 102:Suppl1111132005

    • Search Google Scholar
    • Export Citation
  • 24

    Ito KShin MMatsuzaki MSugasawa KSasaki T: Risk factors for neurological complications after acoustic neurinoma radiosurgery: refinement from further experiences. Int J Radiat Oncol Biol Phys 48:75802000

    • Search Google Scholar
    • Export Citation
  • 25

    Iwai YYamanaka KShiotani MUyama T: Radiosurgery for acoustic neuromas: results of low-dose treatment. Neurosurgery 53:2822882003

    • Search Google Scholar
    • Export Citation
  • 26

    Kalapurakal JASilverman CLAkhtar NAndrews DWDownes BThomas PR: Improved trigeminal and facial nerve tolerance following fractionated stereotactic radiotherapy for large acoustic neuromas. Br J Radiol 72:120212071999

    • Search Google Scholar
    • Export Citation
  • 27

    Kamerer DBLunsford LDMøller M: Gamma knife: an alternative treatment for acoustic neurinomas. Ann Otol Rhinol Laryngol 97:6316351988

    • Search Google Scholar
    • Export Citation
  • 28

    Karpinos MTeh BSZeck OCarpenter LSPhan CMai WY: Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery. Int J Radiat Oncol Biol Phys 54:141014212002

    • Search Google Scholar
    • Export Citation
  • 29

    Kaylie DMMcMenomey SO: Microsurgery vs gamma knife radiosurgery for the treatment of vestibular schwannomas. Arch Otolaryngol Head Neck Surg 129:9039062003

    • Search Google Scholar
    • Export Citation
  • 30

    Kida YKobayashi TTanaka TMori Y: Radiosurgery for bilateral neurinomas associated with neurofibromatosis type 2. Surg Neurol 53:3833902000

    • Search Google Scholar
    • Export Citation
  • 31

    Koh ESMillar BAMénard CMichaels HHeydarian MLadak S: Fractionated stereotactic radiotherapy for acoustic neuroma: single-institution experience at The Princess Margaret Hospital. Cancer 109:120312102007

    • Search Google Scholar
    • Export Citation
  • 32

    Kondziolka DLunsford LDMcLaughlin MRFlickinger JC: Long-term outcomes after radiosurgery for acoustic neuromas. N Engl J Med 339:142614331998

    • Search Google Scholar
    • Export Citation
  • 33

    Kondziolka DSubach BRLunsford LDBissonette DJFlickinger JC: Outcomes after gamma knife radiosurgery in solitary acoustic tumors and neurofibromatosis Type 2. Neurosurg Focus 5:3e21998

    • Search Google Scholar
    • Export Citation
  • 34

    Leksell L: A note on the treatment of acoustic tumours. Acta Chir Scand 137:7637651971

  • 35

    Linskey MEJohnstone PAO'Leary MGoetsch S: Radiation exposure of normal temporal bone structures during stereotactically guided gamma knife surgery for vestibular schwannomas. J Neurosurg 98:8008062003

    • Search Google Scholar
    • Export Citation
  • 36

    Linskey MELunsford LDFlickinger JC: Radiosurgery for acoustic neurinomas: early experience. Neurosurgery 26:7367441990

  • 37

    Linskey MELunsford LDFlickinger JC: Tumor control after stereotactic radiosurgery in neurofibromatosis patients with bilateral acoustic tumors. Neurosurgery 31:8298391992

    • Search Google Scholar
    • Export Citation
  • 38

    Lunsford LDNiranjan AFlickinger JCMaitz AKondziolka D: Radiosurgery of vestibular schwannomas: summary of experience in 829 cases. J Neurosurg 102:Suppl1951992005

    • Search Google Scholar
    • Export Citation
  • 39

    Massager NNissim ODelbrouck CDevriendt DDavid PDesmedt F: Role of intracanalicular volumetric and dosimetric parameters on hearing preservation after vestibular schwannoma radiosurgery. Int J Radiat Oncol Biol Phys 64:133113402006

    • Search Google Scholar
    • Export Citation
  • 40

    Mathieu DKondziolka DFlickinger JCNiranjan AWilliamson RMartin JJ: Stereotactic radiosurgery for vestibular schwannomas in patients with neurofibromatosis type 2: an analysis of tumor control, complications, and hearing preservation rates. Neurosurgery 60:4604702007

    • Search Google Scholar
    • Export Citation
  • 41

    Meijer OWWolbers JGBaayen JCSlotman BJ: Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: early results of a prospective clinical study. Int J Radiat Oncol Biol Phys 46:45492000

    • Search Google Scholar
    • Export Citation
  • 42

    Miller RCFoote RLCoffey RJSargent DJGorman DASchomberg PJ: Decrease in cranial nerve complications after radiosurgery for acoustic neuromas: a prospective study of dose and volume. Int J Radiat Oncol Biol Phys 43:3053111999

    • Search Google Scholar
    • Export Citation
  • 43

    Murphy MJChang SDGibbs ICLe QTHai JKim D: Patterns of patient movement during frameless image-guided radiosurgery. Int J Radiat Oncol Biol Phys 55:140014082003

    • Search Google Scholar
    • Export Citation
  • 44

    Myrseth EMøller PPedersen PHVassbotn FSWentzel-Larsen TLund-Johansen M: Vestibular schwannomas: clinical results and quality of life after microsurgery or gamma knife radiosurgery. Neurosurgery 56:9279352005

    • Search Google Scholar
    • Export Citation
  • 45

    Neuhaus OSaleh Avan Oosterhout ASiebler M: Cerebellar infarction after gamma knife radiosurgery of a vestibular schwannoma. Neurology 68:5902007

    • Search Google Scholar
    • Export Citation
  • 46

    Niranjan ALunsford LDFlickinger JCMaitz AKondziolka D: Dose reduction improves hearing preservation rates after intracanalicular acoustic tumor radiosurgery. Neurosurgery 45:7537651999

    • Search Google Scholar
    • Export Citation
  • 47

    Norén G: Long-term complications following gamma knife radiosurgery of vestibular schwannomas. Stereotact Funct Neurosurg 70:1 Suppl65731998

    • Search Google Scholar
    • Export Citation
  • 48

    Ogunrinde OKLunsford LDFlickinger JCKondziolka DS: Cranial nerve preservation after stereotactic radiosurgery for small acoustic tumors. Arch Neurol 52:73791995

    • Search Google Scholar
    • Export Citation
  • 49

    Okunaga TMatsuo THayashi NHayashi YShabani HKKaminogo M: Linear accelerator radiosurgery for vestibular schwannoma: measuring tumor volume changes on serial three-dimensional spoiled gradient-echo magnetic resonance images. J Neurosurg 103:53582005

    • Search Google Scholar
    • Export Citation
  • 50

    Oyama HKobayashi TKida YTanaka TMori YIwakoshi T: Early changes in volume and non-enhanced volume of acoustic neurinoma after stereotactic gamma-radiosurgery. Neurol Med Chir (Tokyo) 34:6076111994

    • Search Google Scholar
    • Export Citation
  • 51

    Paek SHChung HTJeong SSPark CKKim CYKim JE: Hearing preservation after gamma knife stereotactic radiosurgery of vestibular schwannoma. Cancer 104:5805902005

    • Search Google Scholar
    • Export Citation
  • 52

    Park CKJung HWKim JESon YJPaek SHKim DG: Therapeutic strategy for large vestibular schwannomas. J Neurooncol 77:1671712006

    • Search Google Scholar
    • Export Citation
  • 53

    Pellet WRegis JRoche PHDelsanti C: Relative indications for radiosurgery and microsurgery for acoustic schwannoma. Adv Tech Stand Neurosurg 28:2272842003

    • Search Google Scholar
    • Export Citation
  • 54

    Petit JHHudes RSChen TTEisenberg HMSimard JMChin LS: Reduced-dose radiosurgery for vestibular schwannomas. Neurosurgery 49:129913072001

    • Search Google Scholar
    • Export Citation
  • 55

    Poen JCGolby AJForster KMMartin DPChinn DMHancock SL: Fractionated stereotactic radiosurgery and preservation of hearing in patients with vestibular schwannoma: a preliminary report. Neurosurgery 45:129913071999

    • Search Google Scholar
    • Export Citation
  • 56

    Poetker DMJursinic PARunge-Samuelson CLWackym PA: Distortion of magnetic resonance images used in gamma knife radiosurgery treatment planning: implications for acoustic neuroma outcomes. Otol Neurotol 26:122012282005

    • Search Google Scholar
    • Export Citation
  • 57

    Pogodzinski MSHarner SGLink MJ: Patient choice in treatment of vestibular schwannoma. Otolaryngol Head Neck Surg 130:6116162004

    • Search Google Scholar
    • Export Citation
  • 58

    Pollock BE: Management of vestibular schwannomas that enlarge after stereotactic radiosurgery: treatment recommendations based on a 15 year experience. Neurosurgery 58:2412482006

    • Search Google Scholar
    • Export Citation
  • 59

    Pollock BELunsford LDKondziolka DFlickinger JCBissonette DJKelsey SF: Outcome analysis of acoustic neuroma management: a comparison of microsurgery and stereotactic radiosurgery. Neurosurgery 36:2152291995

    • Search Google Scholar
    • Export Citation
  • 60

    Prasad DSteiner MSteiner L: Gamma surgery for vestibular schwannoma. J Neurosurg 92:7457592000

  • 61

    Régis JPellet WDelsanti CDufour HRoche PHThomassin JM: Functional outcome after gamma knife surgery or microsurgery for vestibular schwannomas. J Neurosurg 97:109111002002

    • Search Google Scholar
    • Export Citation
  • 62

    Roos DEBrophy BPZavgorodni SFFrancis JW: Radiosurgery at the Royal Adelaide Hospital: the first 4 1/2 years' clinical experience. Australas Radiol 44:1851922000

    • Search Google Scholar
    • Export Citation
  • 63

    Rowe JGRadatz MWWalton LHampshire ASeaman SKemeny AA: Gamma knife stereotactic radiosurgery for unilateral acoustic neuromas. J Neurol Neurosurg Psychiatry 74:153615422003

    • Search Google Scholar
    • Export Citation
  • 64

    Rowe JGRadatz MWWalton LSoanes TRodgers JKemeny AA: Clinical experience with gamma knife stereotactic radiosurgery in the management of vestibular schwannomas secondary to type 2 neurofibromatosis. J Neurol Neurosurg Psychiatry 74:128812932003

    • Search Google Scholar
    • Export Citation
  • 65

    Rutten IBaumert BGSeidel LKotolenko SCollignon JKaschten B: Long-term follow-up reveals low toxicity of radiosurgery for vestibular schwannoma. Radiother Oncol 82:83892007

    • Search Google Scholar
    • Export Citation
  • 66

    Schulder MSreepada GSKwartler JACho ES: Microsurgical removal of a vestibular schwannoma after stereotactic radiosurgery: surgical and pathologic findings. Am J Otol 20:3643681999

    • Search Google Scholar
    • Export Citation
  • 67

    Shamisa ABance MNag STator CWong SNorén G: Glioblastoma multiforme occurring in a patient treated with gamma knife surgery. Case report and review of the literature. J Neurosurg 94:8168212001

    • Search Google Scholar
    • Export Citation
  • 68

    Shih HALoeffler JS: Radiation therapy in acromegaly. Rev Endocr Metab Disord 9:59652008

  • 69

    Shirato HSakamoto TTakeichi NAoyama HSuzuki KKagei K: Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): comparison between cystic-type and solid-type VS. Int J Radiat Oncol Biol Phys 48:139514012000

    • Search Google Scholar
    • Export Citation
  • 70

    Solberg TDMedin PMMullins JLi S: Quality assurance of immobilization and target localization systems for frameless stereotactic cranial and extracranial hypofractionated radiotherapy. Int J Radiat Oncol Biol Phys 71:1 SupplS131S1352008

    • Search Google Scholar
    • Export Citation
  • 71

    Song DYWilliams JA: Fractionated stereotactic radiosurgery for treatment of acoustic neuromas. Stereotact Funct Neurosurg 73:45491999

    • Search Google Scholar
    • Export Citation
  • 72

    Spiegelmann RGofman JAlezra DPfeffer R: Radiosurgery for acoustic neurinomas (vestibular schwannomas). Isr Med Assoc J 1:8131999

    • Search Google Scholar
    • Export Citation
  • 73

    Subach BRKondziolka DLunsford LDBissonette DJFlickinger JCMaitz AH: Stereotactic radiosurgery in the management of acoustic neuromas associated with neurofibromatosis Type 2. J Neurosurg 90:8158221999

    • Search Google Scholar
    • Export Citation
  • 74

    Tago MTerahara ANakagawa KAoki YOhtomo KShin M: Immediate neurological deterioration after gamma knife radiosurgery for acoustic neuroma. Case report. J Neurosurg 93:3 Suppl78812000

    • Search Google Scholar
    • Export Citation
  • 75

    Thomsen JTos MBørgesen SE: Gamma knife: hydrocephalus as a complication of stereotactic radiosurgical treatment of an acoustic neuroma. Am J Otol 11:3303331990

    • Search Google Scholar
    • Export Citation
  • 76

    Unger FWalch CHaselsberger KPapaefthymiou GTrummer MEustacchio S: Radiosurgery of vestibular schwannomas: a minimally invasive alternative to microsurgery. Acta Neurochir (Wien) 141:128112861999

    • Search Google Scholar
    • Export Citation
  • 77

    Unger FWalch CSchrottner OEustacchio SSutter BPendl G: Cranial nerve preservation after radiosurgery of vestibular schwannomas. Acta Neurochir Suppl 84:77832002

    • Search Google Scholar
    • Export Citation
  • 78

    van Eck ATHorstmann GA: Increased preservation of functional hearing after gamma knife surgery for vestibular schwannoma. J Neurosurg 102:Suppl2042062005

    • Search Google Scholar
    • Export Citation
  • 79

    Varlotto JMShrieve DCAlexander E IIIKooy HMBlack PMLoeffler JS: Fractionated stereotactic radiotherapy for the treatment of acoustic neuromas: preliminary results. Int J Radiat Oncol Biol Phys 36:1411451996

    • Search Google Scholar
    • Export Citation
  • 80

    Wackym PARunge-Samuelson CLPoetker DMMichel MAAlkaf FMBurg LS: Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes. Otol Neurotol 25:7527612004

    • Search Google Scholar
    • Export Citation
  • 81

    Wang CPHsu WCYoung YH: Vestibular evoked myogenic potentials in neurofibromatosis 2. Ann Otol Rhinol Laryngol 114:69732005

  • 82

    Watanabe TSaito NHirato JShimaguchi HFujimaki HSasaki T: Facial neuropathy due to axonal degeneration and microvasculitis following gamma knife surgery for vestibular schwannoma: a histological analysis. Case report. J Neurosurg 99:9169202003

    • Search Google Scholar
    • Export Citation
  • 83

    Williams JA: Fractionated stereotactic radiotherapy for acoustic neuromas. Int J Radiat Oncol Biol Phys 54:5005042002

  • 84

    Williams JA: Fractionated stereotactic radiotherapy for acoustic neuromas: preservation of function versus size. J Clin Neurosci 10:48522003

    • Search Google Scholar
    • Export Citation
  • 85

    Wowra BMuacevic AJess-Hempen AHempel JMMüller-Schunk STonn JC: Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience. J Neurosurg 102:Suppl1141182005

    • Search Google Scholar
    • Export Citation
  • 86

    Wowra BMuacevic AMuller-Schunk STonn JC: Special indications in gamma knife surgery. Acta Neurochir Suppl (Wien) 91:891022004

    • Search Google Scholar
    • Export Citation
  • 87

    Yang IAranda DHan SJChennupati SSughrue MECheung SW: Hearing preservation after stereotactic radiosurgery for vestibular schwannoma: a systematic review. J Clin Neurosci 16:7427472009

    • Search Google Scholar
    • Export Citation

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Article Information

Contributor Notes

Address correspondence to: Andrew T. Parsa, M.D., Ph.D., Department of Neurological Surgery, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, California 94117. email: parsaa@neurosurg.ucsf.edu.
Headings
Figures
  • View in gallery

    Bar graph showing a comparison of rates of hydrocephalus and symptomatic hydrocephalus between patients receiving > 13 Gy marginal radiation dose and those receiving ≤ 13 Gy. *p > 0.001.

  • View in gallery

    Bar graph showing a comparison of rates of vertigo and balance disturbance and tinnitus between patients receiving > 13 Gy marginal radiation dose and those receiving ≤ 13 Gy. *p > 0.001.

References
  • 1

    Andrews DWSilverman CLGlass JDownes BRiley RJCorn BW: Preservation of cranial nerve function after treatment of acoustic neurinomas with fractionated stereotactic radiotherapy. Preliminary observations in 26 patients. Stereotact Funct Neurosurg 64:1651821995

    • Search Google Scholar
    • Export Citation
  • 2

    Bertalanffy ADietrich WAichholzer MBrix RErtl AHeimberger K: Gamma knife radiosurgery of acoustic neurinomas. Acta Neurochir (Wien) 143:6896952001

    • Search Google Scholar
    • Export Citation
  • 3

    Chung HTMa RToyota BClark BRobar JMcKenzie M: Audiologic and treatment outcomes after linear acceleratorbased stereotactic irradiation for acoustic neuroma. Int J Radiat Oncol Biol Phys 59:111611212004

    • Search Google Scholar
    • Export Citation
  • 4

    Chung WYLiu KDShiau CYWu HMWang LWGuo WY: Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases. J Neurosurg 102:Suppl87962005

    • Search Google Scholar
    • Export Citation
  • 5

    Combs SEThilmann CDebus JSchulz-Ertner D: Long-term outcome of stereotactic radiosurgery (SRS) in patients with acoustic neuromas. Int J Radiat Oncol Biol Phys 64:134113472006

    • Search Google Scholar
    • Export Citation
  • 6

    Combs SEVolk SSchulz-Ertner DHuber PEThilmann CDebus J: Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): long-term results in 106 patients treated in a single institution. Int J Radiat Oncol Biol Phys 63:75812005

    • Search Google Scholar
    • Export Citation
  • 7

    Delbrouck CHassid SMassager NChoufani GDavid PDevriendt D: Preservation of hearing in vestibular schwannomas treated by radiosurgery using Leksell Gamma Knife: preliminary report of a prospective Belgian clinical study. Acta Otorhinolaryngol Belg 57:1972042003

    • Search Google Scholar
    • Export Citation
  • 8

    Flickinger JCKondziolka DNiranjan ALunsford LD: Results of acoustic neuroma radiosurgery: an analysis of 5 years' experience using current methods. J Neurosurg 94:162001

    • Search Google Scholar
    • Export Citation
  • 9

    Flickinger JCKondziolka DNiranjan AMaitz AVoynov GLunsford LD: Acoustic neuroma radiosurgery with marginal tumor doses of 12 to 13 Gy. Int J Radiat Oncol Biol Phys 60:2252302004

    • Search Google Scholar
    • Export Citation
  • 10

    Foote KDFriedman WABuatti JMMeeks SLBova FJKubilis PS: Analysis of risk factors associated with radiosurgery for vestibular schwannoma. J Neurosurg 95:4404492001

    • Search Google Scholar
    • Export Citation
  • 11

    Foote RLCoffey RJSwanson JWHarner SGBeatty CWKline RW: Stereotactic radiosurgery using the gamma knife for acoustic neuromas. Int J Radiat Oncol Biol Phys 32:115311601995

    • Search Google Scholar
    • Export Citation
  • 12

    Franco-Vidal VSongu MBlanchet HBarreau XDarrouzet V: Intracochlear hemorrhage after gamma knife radiosurgery. Otol Neurotol 28:2402442007

    • Search Google Scholar
    • Export Citation
  • 13

    Fuss MDebus JLohr FHuber PRhein BEngenhart-Cabillic R: Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Int J Radiat Oncol Biol Phys 48:138113872000

    • Search Google Scholar
    • Export Citation
  • 14

    Fuss MSalter BJSadeghi AVollmer DGHevezi JMHerman TS: Fractionated stereotactic intensity-modulated radiotherapy (FS-IMRT) for small acoustic neuromas. Med Dosim 27:1471542002

    • Search Google Scholar
    • Export Citation
  • 15

    Hasegawa TFujitani SKatsumata SKida YYoshimoto MKoike J: Stereotactic radiosurgery for vestibular schwannomas: analysis of 317 patients followed more than 5 years. Neurosurgery 57:2572652005

    • Search Google Scholar
    • Export Citation
  • 16

    Hasegawa TKida YKobayashi TYoshimoto MMori YYoshida J: Long-term outcomes in patients with vestibular schwannomas treated using gamma knife surgery: 10-year follow up. J Neurosurg 102:10162005

    • Search Google Scholar
    • Export Citation
  • 17

    Hayhurst CDhir JDias PS: Stereotactic radiosurgery and vestibular schwannoma: hydrocephalus associated with the development of a secondary arachnoid cyst: a report of two cases and review of the literature. Br J Neurosurg 19:1781812005

    • Search Google Scholar
    • Export Citation
  • 18

    Hempel JMHempel EWowra BSchichor ChMuacevic ARiederer A: Functional outcome after gamma knife treatment in vestibular schwannoma. Eur Arch Otorhinolaryngol 263:7147182006

    • Search Google Scholar
    • Export Citation
  • 19

    Hirato MInoue HNakamura MOhye CHirato JShibazaki T: Gamma knife radiosurgery for acoustic schwannoma: early effects and preservation of hearing. Neurol Med Chir (Tokyo) 35:7377411995

    • Search Google Scholar
    • Export Citation
  • 20

    Hirsch ANorén G: Audiological findings after stereotactic radiosurgery in acoustic neurinomas. Acta Otolaryngol 106:2442511988

  • 21

    Hirsch ANorén GAnderson H: Audiologic findings after stereotactic radiosurgery in nine cases of acoustic neurinomas. Acta Otolaryngol 88:1551601979

    • Search Google Scholar
    • Export Citation
  • 22

    Huang CFTu HTLo HKWang KLLiu WS: Radiosurgery for vestibular schwannomas. J Chin Med Assoc 68:3153202005

  • 23

    Inoue HK: Low-dose radiosurgery for large vestibular schwannomas: long-term results of functional preservation. J Neurosurg 102:Suppl1111132005

    • Search Google Scholar
    • Export Citation
  • 24

    Ito KShin MMatsuzaki MSugasawa KSasaki T: Risk factors for neurological complications after acoustic neurinoma radiosurgery: refinement from further experiences. Int J Radiat Oncol Biol Phys 48:75802000

    • Search Google Scholar
    • Export Citation
  • 25

    Iwai YYamanaka KShiotani MUyama T: Radiosurgery for acoustic neuromas: results of low-dose treatment. Neurosurgery 53:2822882003

    • Search Google Scholar
    • Export Citation
  • 26

    Kalapurakal JASilverman CLAkhtar NAndrews DWDownes BThomas PR: Improved trigeminal and facial nerve tolerance following fractionated stereotactic radiotherapy for large acoustic neuromas. Br J Radiol 72:120212071999

    • Search Google Scholar
    • Export Citation
  • 27

    Kamerer DBLunsford LDMøller M: Gamma knife: an alternative treatment for acoustic neurinomas. Ann Otol Rhinol Laryngol 97:6316351988

    • Search Google Scholar
    • Export Citation
  • 28

    Karpinos MTeh BSZeck OCarpenter LSPhan CMai WY: Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery. Int J Radiat Oncol Biol Phys 54:141014212002

    • Search Google Scholar
    • Export Citation
  • 29

    Kaylie DMMcMenomey SO: Microsurgery vs gamma knife radiosurgery for the treatment of vestibular schwannomas. Arch Otolaryngol Head Neck Surg 129:9039062003

    • Search Google Scholar
    • Export Citation
  • 30

    Kida YKobayashi TTanaka TMori Y: Radiosurgery for bilateral neurinomas associated with neurofibromatosis type 2. Surg Neurol 53:3833902000

    • Search Google Scholar
    • Export Citation
  • 31

    Koh ESMillar BAMénard CMichaels HHeydarian MLadak S: Fractionated stereotactic radiotherapy for acoustic neuroma: single-institution experience at The Princess Margaret Hospital. Cancer 109:120312102007

    • Search Google Scholar
    • Export Citation
  • 32

    Kondziolka DLunsford LDMcLaughlin MRFlickinger JC: Long-term outcomes after radiosurgery for acoustic neuromas. N Engl J Med 339:142614331998

    • Search Google Scholar
    • Export Citation
  • 33

    Kondziolka DSubach BRLunsford LDBissonette DJFlickinger JC: Outcomes after gamma knife radiosurgery in solitary acoustic tumors and neurofibromatosis Type 2. Neurosurg Focus 5:3e21998

    • Search Google Scholar
    • Export Citation
  • 34

    Leksell L: A note on the treatment of acoustic tumours. Acta Chir Scand 137:7637651971

  • 35

    Linskey MEJohnstone PAO'Leary MGoetsch S: Radiation exposure of normal temporal bone structures during stereotactically guided gamma knife surgery for vestibular schwannomas. J Neurosurg 98:8008062003

    • Search Google Scholar
    • Export Citation
  • 36

    Linskey MELunsford LDFlickinger JC: Radiosurgery for acoustic neurinomas: early experience. Neurosurgery 26:7367441990

  • 37

    Linskey MELunsford LDFlickinger JC: Tumor control after stereotactic radiosurgery in neurofibromatosis patients with bilateral acoustic tumors. Neurosurgery 31:8298391992

    • Search Google Scholar
    • Export Citation
  • 38

    Lunsford LDNiranjan AFlickinger JCMaitz AKondziolka D: Radiosurgery of vestibular schwannomas: summary of experience in 829 cases. J Neurosurg 102:Suppl1951992005

    • Search Google Scholar
    • Export Citation
  • 39

    Massager NNissim ODelbrouck CDevriendt DDavid PDesmedt F: Role of intracanalicular volumetric and dosimetric parameters on hearing preservation after vestibular schwannoma radiosurgery. Int J Radiat Oncol Biol Phys 64:133113402006

    • Search Google Scholar
    • Export Citation
  • 40

    Mathieu DKondziolka DFlickinger JCNiranjan AWilliamson RMartin JJ: Stereotactic radiosurgery for vestibular schwannomas in patients with neurofibromatosis type 2: an analysis of tumor control, complications, and hearing preservation rates. Neurosurgery 60:4604702007

    • Search Google Scholar
    • Export Citation
  • 41

    Meijer OWWolbers JGBaayen JCSlotman BJ: Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: early results of a prospective clinical study. Int J Radiat Oncol Biol Phys 46:45492000

    • Search Google Scholar
    • Export Citation
  • 42

    Miller RCFoote RLCoffey RJSargent DJGorman DASchomberg PJ: Decrease in cranial nerve complications after radiosurgery for acoustic neuromas: a prospective study of dose and volume. Int J Radiat Oncol Biol Phys 43:3053111999

    • Search Google Scholar
    • Export Citation
  • 43

    Murphy MJChang SDGibbs ICLe QTHai JKim D: Patterns of patient movement during frameless image-guided radiosurgery. Int J Radiat Oncol Biol Phys 55:140014082003

    • Search Google Scholar
    • Export Citation
  • 44

    Myrseth EMøller PPedersen PHVassbotn FSWentzel-Larsen TLund-Johansen M: Vestibular schwannomas: clinical results and quality of life after microsurgery or gamma knife radiosurgery. Neurosurgery 56:9279352005

    • Search Google Scholar
    • Export Citation
  • 45

    Neuhaus OSaleh Avan Oosterhout ASiebler M: Cerebellar infarction after gamma knife radiosurgery of a vestibular schwannoma. Neurology 68:5902007

    • Search Google Scholar
    • Export Citation
  • 46

    Niranjan ALunsford LDFlickinger JCMaitz AKondziolka D: Dose reduction improves hearing preservation rates after intracanalicular acoustic tumor radiosurgery. Neurosurgery 45:7537651999

    • Search Google Scholar
    • Export Citation
  • 47

    Norén G: Long-term complications following gamma knife radiosurgery of vestibular schwannomas. Stereotact Funct Neurosurg 70:1 Suppl65731998

    • Search Google Scholar
    • Export Citation
  • 48

    Ogunrinde OKLunsford LDFlickinger JCKondziolka DS: Cranial nerve preservation after stereotactic radiosurgery for small acoustic tumors. Arch Neurol 52:73791995

    • Search Google Scholar
    • Export Citation
  • 49

    Okunaga TMatsuo THayashi NHayashi YShabani HKKaminogo M: Linear accelerator radiosurgery for vestibular schwannoma: measuring tumor volume changes on serial three-dimensional spoiled gradient-echo magnetic resonance images. J Neurosurg 103:53582005

    • Search Google Scholar
    • Export Citation
  • 50

    Oyama HKobayashi TKida YTanaka TMori YIwakoshi T: Early changes in volume and non-enhanced volume of acoustic neurinoma after stereotactic gamma-radiosurgery. Neurol Med Chir (Tokyo) 34:6076111994

    • Search Google Scholar
    • Export Citation
  • 51

    Paek SHChung HTJeong SSPark CKKim CYKim JE: Hearing preservation after gamma knife stereotactic radiosurgery of vestibular schwannoma. Cancer 104:5805902005

    • Search Google Scholar
    • Export Citation
  • 52

    Park CKJung HWKim JESon YJPaek SHKim DG: Therapeutic strategy for large vestibular schwannomas. J Neurooncol 77:1671712006

    • Search Google Scholar
    • Export Citation
  • 53

    Pellet WRegis JRoche PHDelsanti C: Relative indications for radiosurgery and microsurgery for acoustic schwannoma. Adv Tech Stand Neurosurg 28:2272842003

    • Search Google Scholar
    • Export Citation
  • 54

    Petit JHHudes RSChen TTEisenberg HMSimard JMChin LS: Reduced-dose radiosurgery for vestibular schwannomas. Neurosurgery 49:129913072001

    • Search Google Scholar
    • Export Citation
  • 55

    Poen JCGolby AJForster KMMartin DPChinn DMHancock SL: Fractionated stereotactic radiosurgery and preservation of hearing in patients with vestibular schwannoma: a preliminary report. Neurosurgery 45:129913071999

    • Search Google Scholar
    • Export Citation
  • 56

    Poetker DMJursinic PARunge-Samuelson CLWackym PA: Distortion of magnetic resonance images used in gamma knife radiosurgery treatment planning: implications for acoustic neuroma outcomes. Otol Neurotol 26:122012282005

    • Search Google Scholar
    • Export Citation
  • 57

    Pogodzinski MSHarner SGLink MJ: Patient choice in treatment of vestibular schwannoma. Otolaryngol Head Neck Surg 130:6116162004

    • Search Google Scholar
    • Export Citation
  • 58

    Pollock BE: Management of vestibular schwannomas that enlarge after stereotactic radiosurgery: treatment recommendations based on a 15 year experience. Neurosurgery 58:2412482006

    • Search Google Scholar
    • Export Citation
  • 59

    Pollock BELunsford LDKondziolka DFlickinger JCBissonette DJKelsey SF: Outcome analysis of acoustic neuroma management: a comparison of microsurgery and stereotactic radiosurgery. Neurosurgery 36:2152291995

    • Search Google Scholar
    • Export Citation
  • 60

    Prasad DSteiner MSteiner L: Gamma surgery for vestibular schwannoma. J Neurosurg 92:7457592000

  • 61

    Régis JPellet WDelsanti CDufour HRoche PHThomassin JM: Functional outcome after gamma knife surgery or microsurgery for vestibular schwannomas. J Neurosurg 97:109111002002

    • Search Google Scholar
    • Export Citation
  • 62

    Roos DEBrophy BPZavgorodni SFFrancis JW: Radiosurgery at the Royal Adelaide Hospital: the first 4 1/2 years' clinical experience. Australas Radiol 44:1851922000

    • Search Google Scholar
    • Export Citation
  • 63

    Rowe JGRadatz MWWalton LHampshire ASeaman SKemeny AA: Gamma knife stereotactic radiosurgery for unilateral acoustic neuromas. J Neurol Neurosurg Psychiatry 74:153615422003

    • Search Google Scholar
    • Export Citation
  • 64

    Rowe JGRadatz MWWalton LSoanes TRodgers JKemeny AA: Clinical experience with gamma knife stereotactic radiosurgery in the management of vestibular schwannomas secondary to type 2 neurofibromatosis. J Neurol Neurosurg Psychiatry 74:128812932003

    • Search Google Scholar
    • Export Citation
  • 65

    Rutten IBaumert BGSeidel LKotolenko SCollignon JKaschten B: Long-term follow-up reveals low toxicity of radiosurgery for vestibular schwannoma. Radiother Oncol 82:83892007

    • Search Google Scholar
    • Export Citation
  • 66

    Schulder MSreepada GSKwartler JACho ES: Microsurgical removal of a vestibular schwannoma after stereotactic radiosurgery: surgical and pathologic findings. Am J Otol 20:3643681999

    • Search Google Scholar
    • Export Citation
  • 67

    Shamisa ABance MNag STator CWong SNorén G: Glioblastoma multiforme occurring in a patient treated with gamma knife surgery. Case report and review of the literature. J Neurosurg 94:8168212001

    • Search Google Scholar
    • Export Citation
  • 68

    Shih HALoeffler JS: Radiation therapy in acromegaly. Rev Endocr Metab Disord 9:59652008

  • 69

    Shirato HSakamoto TTakeichi NAoyama HSuzuki KKagei K: Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): comparison between cystic-type and solid-type VS. Int J Radiat Oncol Biol Phys 48:139514012000

    • Search Google Scholar
    • Export Citation
  • 70

    Solberg TDMedin PMMullins JLi S: Quality assurance of immobilization and target localization systems for frameless stereotactic cranial and extracranial hypofractionated radiotherapy. Int J Radiat Oncol Biol Phys 71:1 SupplS131S1352008

    • Search Google Scholar
    • Export Citation
  • 71

    Song DYWilliams JA: Fractionated stereotactic radiosurgery for treatment of acoustic neuromas. Stereotact Funct Neurosurg 73:45491999

    • Search Google Scholar
    • Export Citation
  • 72

    Spiegelmann RGofman JAlezra DPfeffer R: Radiosurgery for acoustic neurinomas (vestibular schwannomas). Isr Med Assoc J 1:8131999

    • Search Google Scholar
    • Export Citation
  • 73

    Subach BRKondziolka DLunsford LDBissonette DJFlickinger JCMaitz AH: Stereotactic radiosurgery in the management of acoustic neuromas associated with neurofibromatosis Type 2. J Neurosurg 90:8158221999

    • Search Google Scholar
    • Export Citation
  • 74

    Tago MTerahara ANakagawa KAoki YOhtomo KShin M: Immediate neurological deterioration after gamma knife radiosurgery for acoustic neuroma. Case report. J Neurosurg 93:3 Suppl78812000

    • Search Google Scholar
    • Export Citation
  • 75

    Thomsen JTos MBørgesen SE: Gamma knife: hydrocephalus as a complication of stereotactic radiosurgical treatment of an acoustic neuroma. Am J Otol 11:3303331990

    • Search Google Scholar
    • Export Citation
  • 76

    Unger FWalch CHaselsberger KPapaefthymiou GTrummer MEustacchio S: Radiosurgery of vestibular schwannomas: a minimally invasive alternative to microsurgery. Acta Neurochir (Wien) 141:128112861999

    • Search Google Scholar
    • Export Citation
  • 77

    Unger FWalch CSchrottner OEustacchio SSutter BPendl G: Cranial nerve preservation after radiosurgery of vestibular schwannomas. Acta Neurochir Suppl 84:77832002

    • Search Google Scholar
    • Export Citation
  • 78

    van Eck ATHorstmann GA: Increased preservation of functional hearing after gamma knife surgery for vestibular schwannoma. J Neurosurg 102:Suppl2042062005

    • Search Google Scholar
    • Export Citation
  • 79

    Varlotto JMShrieve DCAlexander E IIIKooy HMBlack PMLoeffler JS: Fractionated stereotactic radiotherapy for the treatment of acoustic neuromas: preliminary results. Int J Radiat Oncol Biol Phys 36:1411451996

    • Search Google Scholar
    • Export Citation
  • 80

    Wackym PARunge-Samuelson CLPoetker DMMichel MAAlkaf FMBurg LS: Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes. Otol Neurotol 25:7527612004

    • Search Google Scholar
    • Export Citation
  • 81

    Wang CPHsu WCYoung YH: Vestibular evoked myogenic potentials in neurofibromatosis 2. Ann Otol Rhinol Laryngol 114:69732005

  • 82

    Watanabe TSaito NHirato JShimaguchi HFujimaki HSasaki T: Facial neuropathy due to axonal degeneration and microvasculitis following gamma knife surgery for vestibular schwannoma: a histological analysis. Case report. J Neurosurg 99:9169202003

    • Search Google Scholar
    • Export Citation
  • 83

    Williams JA: Fractionated stereotactic radiotherapy for acoustic neuromas. Int J Radiat Oncol Biol Phys 54:5005042002

  • 84

    Williams JA: Fractionated stereotactic radiotherapy for acoustic neuromas: preservation of function versus size. J Clin Neurosci 10:48522003

    • Search Google Scholar
    • Export Citation
  • 85

    Wowra BMuacevic AJess-Hempen AHempel JMMüller-Schunk STonn JC: Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience. J Neurosurg 102:Suppl1141182005