Stereotactic radiosurgery for vestibular schwannomas: average 10-year follow-up results focusing on long-term hearing preservation

OBJECTIVEThe aim of this study was to reappraise long-term treatment outcomes of stereotactic radiosurgery (SRS) for vestibular schwannomas (VSs). The authors used a database that included patients who underwent SRS with a unique dose-planning technique, i.e., partial tumor coverage designed to avoid excess irradiation of the facial and cochlear nerves, focusing on tumor control and hearing preservation. Clinical factors associated with post-SRS tumor control and long-term hearing preservation were also analyzed.METHODSThis institutional review board–approved, retrospective cohort study used the authors' prospectively accumulated database. Among 207 patients who underwent Gamma Knife SRS for VSs between 1990 and 2005, 183 (who were followed up for at least 36 post-SRS months) were studied. The median tumor volume was 2.0 cm3 (range 0.05–26.2 cm3). The median prescribed dose at the tumor periphery was 12.0 Gy (range 8.8–15.0 Gy; 12.0 Gy was used in 171 patients [93%]), whereas tumor portions facing the facial and cochlear nerves were irradiated with 10.0 Gy. As a result, 72%–99% of each tumor was irradiated with the prescribed dose. The mean cochlear doses ranged from 2.3 to 5.7 Gy (median 4.1 Gy).RESULTSThe median durations of imaging and audiometric follow-up were 114 months (interquartile range 73–144 months) and 59 months (interquartile range 33–109 months), respectively. Tumor shrinkage was documented in 110 (61%), no change in 48 (27%), and enlargement in the other 22 (12%) patients. A further procedure (FP) was required in 15 (8%) patients. Thus, the tumor growth control rate was 88% and the clinical control rate (i.e., no need for an FP) was 92%. The cumulative FP-free rates were 96%, 93%, and 87% at the 60th, 120th, and 180th post-SRS month, respectively. Six (3%) patients experienced facial pain, and 2 developed transient facial palsy. Serviceable hearing was defined as a pure tone audiogram result better than 50 dB. Among the 66 patients with serviceable hearing before SRS who were followed up, hearing acuity was preserved in 23 (35%). Actuarial serviceable hearing preservation rates were 49%, 24%, and 12% at the 60th, 120th, and 180th post-SRS month, respectively. On univariable analysis, only cystic-type tumor (HR 3.36, 95% CI 1.18–9.36; p = 0.02) was shown to have a significantly unfavorable association with FP. Multivariable analysis followed by univariable analysis revealed that higher age (≥ 65 years: HR 2.66, 95% CI 1.16–5.92; p = 0.02), larger tumor volume (≥ 8 cm3: HR 5.36, 95% CI 1.20–17.4; p = 0.03), and higher cochlear dose (mean cochlear dose > 4.2 Gy: HR 2.22, 95% CI 1.07–4.77; p = 0.03) were unfavorable factors for hearing preservation.CONCLUSIONSStereotactic radiosurgery achieved good long-term results in this series. Tumor control was acceptable, and there were few serious complications in patients with small- to medium-sized VSs. Unfortunately, hearing preservation was not satisfactory. However, the longer the observation period, the more important it becomes to compare post-SRS hearing decreases with the natural decline in untreated cases.

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Stereotactic radiosurgery as the primary management for patients with Koos grade IV vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2020.8.jns201832 ◽

2021 ◽

pp. 1-9

Author(s):

Akiyoshi Ogino ◽

L. Dade Lunsford ◽

Hao Long ◽

Stephen Johnson ◽

Andrew Faramand ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Tumor Volume ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Tumor Diameter ◽

Single Session ◽

Lower Margin ◽

Long Term Outcome

OBJECTIVEWhile extensive long-term outcome studies support the role of stereotactic radiosurgery (SRS) for smaller-volume vestibular schwannomas (VSs), its role in the management for larger-volume tumors remains controversial.METHODSBetween 1987 and 2017, the authors performed single-session SRS on 170 patients with previously untreated Koos grade IV VSs (volumes ranged from 5 to 20 cm3). The median tumor volume was 7.4 cm3. The median maximum extracanalicular tumor diameter was 27.5 mm. All tumors compressed the middle cerebellar peduncle and distorted the fourth ventricle. Ninety-three patients were male, 77 were female, and the median age was 61 years. Sixty-two patients had serviceable hearing (Gardner-Robertson [GR] grades I and II). The median margin dose was 12.5 Gy.RESULTSAt a median follow-up of 5.1 years, the progression-free survival rates of VSs treated with a margin dose ≥ 12.0 Gy were 98.4% at 3 years, 95.3% at 5 years, and 90.7% at 10 years. In contrast, the tumor control rate after delivery of a margin dose < 12.0 Gy was 76.9% at 3, 5, and 10 years. The hearing preservation rates in patients with serviceable hearing at the time of SRS were 58.1% at 3 years, 50.3% at 5 years, and 35.9% at 7 years. Younger age (< 60 years, p = 0.036) and initial GR grade I (p = 0.006) were associated with improved serviceable hearing preservation rate. Seven patients (4%) developed facial neuropathy during the follow-up interval. A smaller tumor volume (< 10 cm3, p = 0.002) and a lower margin dose (≤ 13.0 Gy, p < 0.001) were associated with preservation of facial nerve function. The probability of delayed facial neuropathy when the margin dose was ≤ 13.0 Gy was 1.1% at 10 years. Nine patients (5%) required a ventriculoperitoneal shunt because of delayed symptomatic hydrocephalus. Fifteen patients (9%) developed detectable trigeminal neuropathy. Delayed resection was performed in 4% of patients.CONCLUSIONSEven for larger-volume VSs, single-session SRS prevented the need for delayed resection in almost 90% at 10 years. For patients with minimal symptoms of tumor mass effect, SRS should be considered an effective alternative to surgery in most patients, especially those with advanced age or medical comorbidities.

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Gamma Knife radiosurgery for treatment of growing vestibular schwannomas in patients with neurofibromatosis Type 2: a matched cohort study with sporadic vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2016.9.jns161463 ◽

2018 ◽

Vol 128 (1) ◽

pp. 49-59 ◽

Cited By ~ 11

Author(s):

Ivo J. Kruyt ◽

Jeroen B. Verheul ◽

Patrick E. J. Hanssens ◽

Henricus P. M. Kunst

Keyword(s):

Gamma Knife ◽

Tumor Volume ◽

Gamma Knife Radiosurgery ◽

Neurofibromatosis Type ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Nerve Function

OBJECTIVENeurofibromatosis Type 2 (NF2) is a tumor syndrome characterized by an autosomal dominant pattern of inheritance. The hallmark of NF2 is the development of bilateral vestibular schwannomas (VSs), generally by 30 years of age. One of the first-line treatment options for small to medium-large VSs is radiosurgery. Although radiosurgery shows excellent results in sporadic VS, its use in NF2-related VS is still a topic of dispute. The aim of this study was to evaluate long-term tumor control, hearing preservation rates, and factors influencing outcome of optimally dosed, contemporary Gamma Knife radiosurgery (GKRS) for growing VSs in patients with NF2 and compare the findings to data obtained in patients with sporadic VS also treated by means of GKRS.METHODSThe authors performed a retrospective analysis of 47 growing VSs in 34 NF2 patients who underwent GKRS treatment performed with either the Model C or Perfexion Leksell Gamma Knife, with a median margin dose of 11 Gy. Actuarial tumor control rates were estimated using the Kaplan-Meier method. For patient- and treatment-related factors, a Cox proportional hazards model was used to identify predictors of outcome. Trigeminal, facial, and vestibulocochlear nerve function were assessed before and after treatment. NF2-related VS patients were matched 1:1 with sporadic VS patients who were treated in the same institute, and the same indications for treatment, definitions, and dosimetry were used in order to compare outcomes.RESULTSActuarial tumor control rates in NF2 patients after 1, 3, 5, and 8 years were 98%, 89%, 87%, and 87%, respectively. Phenotype and tumor volume had significant hazard rates of 0.086 and 22.99, respectively, showing that Feiling-Gardner phenotype and a tumor volume not exceeding 6 cm3 both were associated with significantly better outcome. Actuarial rates of serviceable hearing preservation after 1, 3, 5, and 7 years were 95%, 82%, 59%, and 33%, respectively. None of the patients experienced worsening of trigeminal nerve function. Facial nerve function worsened in 1 patient (2.5%). No significant differences in tumor control, hearing preservation, or complications were found in comparing the results of GKRS for NF2-related VS versus GKRS for sporadic VS.CONCLUSIONSWith modern GKRS, the use of low margin doses for treating growing VSs in patients with NF2 demonstrates good long-term tumor control rates. Feiling-Gardner phenotype and tumor volume smaller than 6 cm3 seem to be independently associated with prolonged progression-free survival, highlighting the clinical importance of phenotype assessment before GKRS treatment. In addition, no significant differences in tumor control rates or complications were found in the matched-control cohort analysis comparing GKRS for VS in patients with NF2 and GKRS for sporadic VS. These results show that GKRS is a valid treatment option for NF2-related VS, in addition to being a good option for sporadic VS, particularly in patients with the Feiling-Gardner phenotype and/or tumors that are small to medium in size. Larger tumors in patients with the Wishart phenotype appear to respond poorly to radiosurgery, and other treatment modalities should therefore be considered in such cases.

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STEREOTACTIC RADIOSURGERY FOR VESTIBULAR SCHWANNOMAS IN PATIENTS WITH NEUROFIBROMATOSIS TYPE 2

Neurosurgery ◽

10.1227/01.neu.0000255340.26027.53 ◽

2007 ◽

Vol 60 (3) ◽

pp. 460-470 ◽

Cited By ~ 102

Author(s):

David Mathieu ◽

Douglas Kondziolka ◽

John C. Flickinger ◽

Ajay Niranjan ◽

Richard Williamson ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Tumor Volume ◽

Gamma Knife Radiosurgery ◽

Neurofibromatosis Type ◽

Hearing Preservation ◽

Neurofibromatosis Type 2 ◽

Vestibular Schwannomas ◽

Factors Affecting

Abstract OBJECTIVE Vestibular schwannomas present significant management challenges in patients with neurofibromatosis Type 2 (NF2). We evaluated the results of gamma knife radiosurgery for the management of these tumors, focusing on tumor response, hearing preservation, and other factors affecting outcomes. METHODS Stereotactic radiosurgery was performed to manage 74 schwannomas in 62 patients. Ipsilateral serviceable hearing was present in 35% of tumors before the procedure. The mean tumor volume was 5.7 cm3. The mean margin and maximum dose used were 14 and 27.5 Gy, respectively. Cox regression analyses were performed to identify factors affecting outcomes. RESULTS The median follow-up period was 53 months, and two patients were lost to follow-up. Actuarial local control rates at were 85, 81, and 81% at 5, 10, and 15 years, respectively. Tumor volume was significant as a predictor of local control. Since 1992, using current radiosurgery techniques (magnetic resonance imaging scan targeting and reduced margin dose to 14 Gy or less), the actuarial serviceable hearing preservation rate is 73% at 1 year, 59% at 2 years, and 48% at 5 years after radiosurgery. Facial neuropathy occurred in 8% of tumors, trigeminal neuropathy occurred in 4%, and vestibular dysfunction occurred in 4%. Radiation dose and tumor volume were predictive of development of new deficits. No radiosurgery-associated secondary tumors or atypical or malignant changes were noted. CONCLUSION Stereotactic radiosurgery is a safe and effective management modality for neurofibromatosis Type 2 vestibular schwannomas. Although results do not seem to be as good as for patients with sporadic unilateral tumors, gamma knife radiosurgery results seem favorable and indicate that radiosurgery should be strongly considered for primary tumor management in selected patients.

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Multisession Stereotactic Radiosurgery for Vestibular Schwannomas: Single-Institution Experience With 383 Cases

Neurosurgery ◽

10.1227/neu.0b013e318222e451 ◽

2011 ◽

Vol 69 (6) ◽

pp. 1200-1209 ◽

Cited By ~ 51

Author(s):

Ake Hansasuta ◽

Clara Y. H. Choi ◽

Iris C. Gibbs ◽

Scott G. Soltys ◽

Victor C. K. Tse ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Tumor Volume ◽

Medical Center ◽

Neurofibromatosis Type ◽

Hearing Preservation ◽

Additional Treatment ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Complication Rates ◽

Kaplan Meier

Abstract BACKGROUND Single-session stereotactic radiosurgery (SRS) treatment of vestibular schwannomas results in excellent tumor control. It is not known whether functional outcomes can be improved by fractionating the treatment over multiple sessions. OBJECTIVE To examine tumor control and complication rates after multisession SRS. METHODS Three hundred eighty-three patients treated with SRS from 1999 to 2007 at Stanford University Medical Center were retrospectively reviewed. Ninety percent were treated with 18 Gy in 3 sessions, targeting a median tumor volume of 1.1 cm3 (range, 0.02-19.8 cm3). RESULTS During a median follow-up duration of 3.6 years (range, 1-10 years), 10 tumors required additional treatment, resulting in 3- and 5-year Kaplan-Meier tumor control rates of 99% and 96%, respectively. Five-year tumor control rate was 98% for tumors > 3.4 cm3. Neurofibromatosis type 2–associated tumors were associated with worse tumor control (P = .02). Of the 200 evaluable patients with pre-SRS serviceable hearing (Gardner-Robertson grade 1 and 2), the crude rate of serviceable hearing preservation was 76%. Smaller tumor volume was associated with hearing preservation (P = .001). There was no case of post-SRS facial weakness. Eight patients (2%) developed trigeminal dysfunction, half of which was transient. CONCLUSION Multisession SRS treatment of vestibular schwannomas results in an excellent rate of tumor control. The hearing, trigeminal nerve, and facial nerve function preservation rates reported here are promising.

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PC3 - 141 Long-Term Results of Stereotactic Radiosurgery for Skull Base Meningiomas

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/cjn.2016.392 ◽

2016 ◽

Vol 43 (S4) ◽

pp. S21-S21

Author(s):

O. Cohen-Inbar

Keyword(s):

Tumor Progression ◽

Skull Base ◽

Clinical Improvement ◽

Tumor Volume ◽

Long Term Results ◽

Tumor Control ◽

Long Term Outcome ◽

Skull Base Meningiomas

Gamma knife radiosurgery (GKRS) is well-established in the management of inaccessible, recurrent, or residual benign skull base meningiomas. Most series report clinical outcome parameters and complications in the short -intermediate period after radiosurgery. Reports of long-term tumor control and neurological status are still lacking. Objective: We report the presentation, treatment, and long-term outcome of skull base meningiomas after GKRS. Methods: From a prospectively collected IRB approved database, we selected patients with a WHO grade I skull base meningioma treated with a single-session GKRS and a minimum of 60 months follow up. 135 patients, 54.1% males (n=73) form the cohort. Median age was 54 years (19-80). Median tumor volume was 4.7 cm3 (0.5-23). Median margin dose was 15 Gy (7.5-36). Median follow up was 102.5 months (60.1-235.4). Patient and tumor characteristics were assessed to determine predictors of neurological function and tumor progression. Results: At last follow up, tumor volume control was achieved in 88.1% (n=119). Post-GKRS clinical improvement or stability was reported in 61.5%. The 5, 10, and 15 years actuarial progression free survival rates are 100%, 95.4%, and 68.8%, respectively. Favorable outcome (both tumor control and clinical preservation/improvement) was attained in 60.8% (n=79). Pre-GKRS performance status (KPS) was shown to influence tumor progression (p=0.0001) and post-GKRS clinical improvement / preservation (p=0.003). Conclusion: GKRS offers a highly durable rate of tumor control for WHO-I skull base meningiomas, with an acceptably low incidence of neurological deficits. KPS at the time of radiosurgery serves as a reliable long-term predictor of overall outcome.

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Long-term follow-up studies of Gamma Knife surgery for patients with neurofibromatosis Type 2

Journal of Neurosurgery ◽

10.3171/2014.8.gks141503 ◽

2014 ◽

Vol 121 (Suppl_2) ◽

pp. 143-149 ◽

Cited By ~ 15

Author(s):

Shibin Sun ◽

Ali Liu

Keyword(s):

Gamma Knife ◽

Neurofibromatosis Type ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Tumor Control ◽

History Of ◽

The Mean

ObjectThe aim of this study was to evaluate long-term clinical outcomes after Gamma Knife surgery (GKS) for patients with neurofibromatosis Type 2 (NF2) and the role of GKS in the management of NF2.MethodsFrom December 1994 through December 2008, a total of 46 patients (21 male, 25 female) with NF2 underwent GKS and follow-up evaluation for at least 5 years at the Gamma Knife Center of the Beijing Neurosurgical Institute. GKS was performed using the Leksell Gamma Knife Models B and C. The mean age of the patients was 30 years (range 13–59 years). A family history of NF2 was found for 9 (20%) patients. The NF2 phenotype was thought to be Wishart for 20 (44%) and Feiling-Gardner for 26 (56%) patients. Among these 46 patients, GKS was performed to treat 195 tumors (73 vestibular schwannomas and 122 other tumors including other schwannomas and meningiomas). For vestibular schwannomas, the mean volume was 5.1 cm3 (median 3.6 cm3, range 0.3–27.3 cm3), the mean margin dose was 12.9 Gy (range 10–14 Gy), and the mean maximum dose was 27.3 Gy (range 16.2–40 Gy). For other tumors, the mean volume was 1.7 cm3 (range 0.3–5.5 cm3), the mean margin dose was 13.3 Gy (range 11–14 Gy), and the mean maximum dose was 26.0 Gy (range 18.0–30.4 Gy). The median duration of follow-up was 109 months (range 8–195 months).ResultsFor the 73 vestibular schwannomas that underwent GKS, the latest follow-up MR images demonstrated regression of 30 (41%) tumors, stable size for 31 (43%) tumors, and enlargement of 12 (16%) tumors. The total rate of tumor control for bilateral vestibular schwannomas in patients with NF2 was 84%. Of the 122 other types of tumors that underwent GKS, 103 (85%) showed no tumor enlargement. The rate of serviceable hearing preservation after GKS was 31.9% (15/47). The actuarial rates for hearing preservation at 3 years, 5 years, 10 years, and 15 years were 98%, 93%, 44%, and 17%, respectively. Of the 46 patients, 22 (48%) became completely bilaterally deaf, 17 (37%) retained unilateral serviceable hearing, and 7 (15%) retained bilateral serviceable hearing. The mean history of the disease course was 12 years (range 5–38 years).ConclusionsGKS was confirmed to provide long-term local tumor control for small- to medium-sized vestibular schwannomas and other types of tumors, although vestibular schwannomas in patients with NF2 responded less well than did unilateral sporadic vestibular schwannomas. Phenotype is the most strongly predictive factor of final outcome after GKS for patients with NF2. The risk for loss of hearing is high, whereas the risk for other cranial nerve complications is low.

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Primary Treatment of Small-To-Medium (<3cm) Sporadic Vestibular Schwannomas: A Systematic Review And Meta-Analysis on Long-Term Hearing Preservation And Tumor Control Rates For Microsurgery Versus Radiosurgery.

10.21203/rs.3.rs-827189/v1 ◽

2021 ◽

Author(s):

Amey Rajan Savardekar ◽

Danielle L Terrell ◽

Saudamini Jayant Lele ◽

Ryan Robert Diaz ◽

Praneeth Reddy Keesari ◽

...

Keyword(s):

Systematic Review ◽

Stereotactic Radiosurgery ◽

Meta Analysis ◽

Treatment Options ◽

Hearing Preservation ◽

Primary Treatment ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Group 10

Abstract BackgroundOver the past two decades, the treatment of small-to-medium (<3cm) sporadic vestibular schwannomas (VS) has experienced a definite shift to stereotactic radiosurgery vis-a-vis microsurgery. We performed a systematic review and meta-analysis of VS patients primarily treated with stereotactic radiosurgery (SRS) or microsurgery (MS), with particular attention to hearing preservation outcomes (HPO), tumor control (TC), and facial nerve dysfunction (FND).MethodsA systematic review was conducted (Medline and Scopus database) for the period, January 2010 to June 2020 with appropriate MeSH. English language articles for small-to-medium sporadic VS (<3cm) utilizing SRS or MS as treatment modality, with minimum follow-up of 3 years, were included. Studies had to report an acceptable standardized hearing metric. HPO, TC, and FND rates were analyzed. ResultsThirty-two studies met inclusion criteria: 10 for microsurgery; 23 for radiosurgery (one comparative study included in both). HPO, at ~65 months follow-up, were comparable between MS group (10 studies; 809 patients) and SRS group (23 studies; 1234 patients) (56% versus 59%, p=0.1527). TC, at ~70 months follow-up, was significantly better in MS group (9 studies; 1635 patients) versus SRS group (19 studies; 2260 patients) (98% versus 92%, p < 0.0001). FND, at ~ 12 months follow-up, was significantly higher in MS group (8 studies; 1101 patients) versus SRS group (17 studies; 2285 patients) (10% versus 2%, p < 0.0001).ConclusionMS and SRS are comparable primary treatment options for small (<3cm) sporadic VS with respect to HPO at 5-year follow-up in patients with serviceable hearing at presentation. Approximately 50% patients for both modalities will likely lose serviceable hearing by that time-point. High TC rates (>90%) were seen with both modalities, with MS (98%) significantly better than SRS (92%). The post-treatment FND was significantly less with SRS group (2%) versus MS group (10%).

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The Effect of Prescription Isodose Variation on Tumor Control and Toxicities in Stereotactic Radiosurgery for Sporadic Vestibular Schwannoma: Propensity Score-Matched Case–Control Study

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0040-1718908 ◽

2021 ◽

Author(s):

Achiraya Teyateeti ◽

Christopher S. Graffeo ◽

Avital Perry ◽

Eric J. Tryggestad ◽

Paul D. Brown ◽

...

Keyword(s):

Propensity Score ◽

Stereotactic Radiosurgery ◽

Vestibular Schwannoma ◽

Hearing Preservation ◽

Tumor Control ◽

Gamma Knife Stereotactic Radiosurgery ◽

The Impact ◽

Prescription Isodose

Abstract Objective Vestibular schwannoma (VS) treated with Gamma Knife stereotactic radiosurgery (SRS) was typically performed at 50% isodose line (IDL50); however, the impact of IDL variation on outcomes is poorly understood. This study aimed to compare tumor control (TC) and toxicities between treatment at 40% (IDL40) and 50% (IDL50). Methods and Materials Sporadic/unilateral VS patients treated with SRS dose 12 to 14 Gy and prescription isodose volume ≤10cm3 were included. Propensity score matching was applied to IDL40 cohort to generate an IDL50 companion cohort, adjusting for age and prescription isodose volume. After exclusion of patients with follow-up <24 months, there were 30 and 28 patients in IDL40 and IDL50 cohorts, respectively. Results Median follow-up time was 96 months (24–225 months). Actuarial and radiographic TC rates were 91.8% and clinical TC was 96.2% both at 5 and 10 years. TC was higher in IDL40 cohort but not significant (96.4 vs. 86.7%; p = 0.243). Hearing preservation (HP) rates were 71.9 and 39.2% at 5- and 10-year intervals, with significantly higher rates of HP noted in IDL40 cohort (83.3 vs. 57.1% at 5-year interval; 62.5 vs. 11.4% at 10-year interval; p = 0.017). Permanent facial neuropathy occurred in two patients, both from the IDL50 cohort (3.5%). Rates of post-SRS steroid treatment or shunt placement for hydrocephalus were slightly higher in IDL50 patients (6.9 vs. 17.9%; p = 0.208 and 3.3 vs. 7.1%; p = 0.532). Conclusion For treatment of VS with SRS, dose prescription at IDL40 or IDL50 provides excellent long-term TC and toxicity profiles. IDL40 may be associated with improved long-term HP.

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Gamma Knife radiosurgery for vestibular schwannoma: clinical results at long-term follow-up in a series of 379 patients

Journal of Neurosurgery ◽

10.3171/2014.8.gks141506 ◽

2014 ◽

Vol 121 (Suppl_2) ◽

pp. 123-142 ◽

Cited By ~ 55

Author(s):

Nicola Boari ◽

Michele Bailo ◽

Filippo Gagliardi ◽

Alberto Franzin ◽

Marco Gemma ◽

...

Keyword(s):

Gamma Knife ◽

Tumor Volume ◽

Gamma Knife Radiosurgery ◽

Hearing Preservation ◽

Class I ◽

Medium Size ◽

Tumor Control ◽

Long Term Follow Up

ObjectSince the 1990s, Gamma Knife radiosurgery (GKRS) has become the first-line treatment option for small- to medium-size vestibular schwannomas (VSs), especially in patients without mass effect–related symptoms and with functional hearing. The aim of this study was to assess the safety and efficacy of GKRS, in terms of tumor control, hearing preservation, and complications, in a series of 379 consecutive patients treated for VS.MethodsOf 523 patients treated at the authors' institution for VS between 2001 and 2010, the authors included 379 who underwent GKRS as the primary treatment. These patients were not affected by Type 2 neurofibromatosis and had clinical follow-up of at least 36 months. Clinical follow-up (mean and median 75.7 and 69.5 months, respectively) was performed for all patients, whereas audiometric and quantitative radiological follow-up examinations were obtained for only 153 and 219 patients, respectively. The patients' ages ranged from 23 to 85 years (mean 59 years). The mean tumor volume was 1.94 ± 2.2 cm3 (median 1.2 cm3, range 0.013–14.3 cm3), and the median margin dose was 13 Gy (range 11–15 Gy). Parameters considered as determinants of the clinical outcome were long-term tumor control, hearing preservation, and complications. A statistical analysis was performed to correlate clinical outcomes with the radiological features of the tumor, dose-planning parameters, and patient characteristics.ResultsControl of the tumor with GKRS was achieved in 97.1% of the patients. In 82.7% of the patients, the tumor volume had decreased at the last follow-up, with a mean relative reduction of 34.1%. The rate of complications was very low, with most consisting of a transient worsening of preexisting symptoms. Patients who had vertigo, balance disorders, or facial or trigeminal impairment usually experienced a complete or at least significant symptom relief after treatment. However, no significant improvement was observed in patients previously reporting tinnitus. The overall rate of preservation of functional hearing at the long-term follow-up was 49%; in patients with hearing classified as Gardner-Robertson (GR) Class I, this value was 71% and reached 93% among cases of GR Class I hearing in patients younger than 55 years.ConclusionsGamma Knife radiosurgery is a safe and effective treatment for VS, achieving tumor control in 97.1% of cases and resulting in a very low morbidity rate. Younger GR Class I patients had a significantly higher probability of retaining functional hearing even at the 10-year follow-up; for this reason, the time between symptom onset, diagnosis, and treatment should be shortened to achieve better outcomes in functional hearing preservation.

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Predicting hearing outcomes before primary radiosurgery for vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2019.5.jns182765 ◽

2020 ◽

Vol 133 (4) ◽

pp. 1235-1241 ◽

Cited By ~ 1

Author(s):

Stephen Johnson ◽

Hideyuki Kano ◽

Andrew Faramand ◽

Ajay Niranjan ◽

John C. Flickinger ◽

...

Keyword(s):

Tumor Volume ◽

Hearing Preservation ◽

High Rate ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Speech Discrimination ◽

Nerve Preservation ◽

Hearing Outcomes ◽

Preservation Rate

OBJECTIVEOptimizing outcomes in the management of patients with vestibular schwannomas (VSs) requires consideration of the patient’s goals. Earlier recognition of VS by imaging has led to an evolution in management. Stereotactic radiosurgery (SRS) has emerged as a frequently used strategy designed to reduce management risks, obtain long-term tumor control, and preserve current neurological function. The authors analyzed features that impact hearing preservation rates in patients with serviceable hearing prior to SRS.METHODSThe study included 307 patients who had serviceable hearing (Gardner-Robertson hearing scale [GR] grade 1 or 2, speech discrimination score ≥ 50%, pure tone average ≤ 50 dB) at the time of SRS. The authors evaluated parameters that included age, tumor volume, hearing status, disequilibrium, tinnitus, Koos class, sex, and tumor margin dose. The Pittsburgh Hearing Prediction Score (PHPS) was evaluated as a method to predict long-term hearing outcomes in these cases.RESULTSAt a median of 7.6 years after SRS (range 1–23 years), tumor control was achieved in 95% of patients. The overall serviceable hearing preservation rate was 77.8% at 3 years, 68.8% at 5 years, and 51.8% at 10 years. The PHPS assigns a total of 5 points based on patient age (1 point if < 45 years, 2 points if 45–59 years, and 3 points if ≥ 60 years), tumor volume (0 points if < 1.2 cm3, 1 point if ≥ 1.2 cm3), and GR grade (0 points if grade 1 hearing, 1 point if grade 2 hearing) The serviceable hearing preservation rate was 92.3% at 10 years in patients whose score total was 1. In contrast, none of the patients whose PHPS was 5 maintained serviceable hearing at 10 years (p < 0.001).CONCLUSIONSSRS resulted in a high rate of long-term tumor control and cranial nerve preservation. The PHPS helped to predict long-term hearing preservation rates in patients who underwent SRS when they still had serviceable hearing. The best long-term hearing preservation rates were found in younger patients with smaller tumor volumes.

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