Long-term hearing outcomes after gamma knife surgery in patients with vestibular schwannoma with hearing preservation: evaluation in 92 patients with serial audiograms

Abstract BACKGROUND: There are limited data on the long-term auditory symptoms in patients with sporadic small- and medium-sized vestibular schwannoma (VS). The initial treatment strategy for VS is controversial. OBJECTIVE: To characterize auditory symptoms in a large cohort of patients with VS. METHODS: Patients with ⩽3 cm VS who underwent primary microsurgery, gamma knife surgery, or observation between 1998 and 2008 at 2 independent hospitals were identified. Clinical data were extracted from existing VS databases. At a mean time of 7.7 years after initial treatment, patients were surveyed via mail with the use of the Hearing Handicap Inventory for Adults (HHIA) and the Tinnitus Handicap Inventory. RESULTS: The response rate was 79%; a total of 539 respondents were analyzed. Overall, the hearing prognosis was poor, because more than 75% of all patients had nonserviceable hearing at the last clinical follow-up. Good baseline hearing proved to be a strong predictor for maintained serviceable hearing. Treatment modality was independently associated with both audiometric outcome and HHIA results. Active treatment with microsurgery or gamma knife surgery did not appear to be protective, because patients who were observed had the greatest probability of durable hearing. Patients in the surgical series had the greatest hearing loss. Tinnitus Handicap Inventory results were less predictable. The only predictors of tinnitus handicap were age and HHIA score. CONCLUSION: The overall prognosis for hearing in sporadic VS is poor regardless of treatment strategy. Treatment modality was an independent predictor of hearing status; observation was associated with the highest rate of hearing preservation.

Download Full-text

Hearing preservation in patients with vestibular schwannoma treated with Gamma Knife surgery

Journal of Neurosurgery ◽

10.3171/2012.10.jns12880 ◽

2013 ◽

Vol 118 (3) ◽

pp. 571-578 ◽

Cited By ~ 40

Author(s):

Andrew M. Baschnagel ◽

Peter Y. Chen ◽

Dennis Bojrab ◽

Daniel Pieper ◽

Jack Kartush ◽

...

Keyword(s):

Hearing Loss ◽

Gamma Knife ◽

Vestibular Schwannoma ◽

Hearing Preservation ◽

Gamma Knife Surgery ◽

Speech Discrimination ◽

Before And After ◽

Nerve Dysfunction ◽

Preservation Rate

Object Hearing loss after Gamma Knife surgery (GKS) in patients with vestibular schwannoma has been associated with radiation dose to the cochlea. The purpose of this study was to evaluate serviceable hearing preservation in patients with VS who were treated with GKS and to determine if serviceable hearing loss can be correlated with the dose to the cochlea. Methods Forty patients with vestibular schwannoma with serviceable hearing were treated using GKS with a median marginal dose of 12.5 Gy (range 12.5–13 Gy) to the 50% isodose volume. Audiometry was performed prospectively before and after GKS at 1, 3, and 6 months, and then every 6 months thereafter. Hearing preservation was based on pure tone average (PTA) and speech discrimination (SD). Serviceable hearing was defined as PTA less than 50 dB and SD greater than 50%. Results The median cochlear maximum and mean doses were 6.9 Gy (range 1.6–16 Gy) and 2.7 Gy (range 0.7–5.0 Gy), respectively. With a median audiological follow-up of 35 months (range 6–58 months), the 1-, 2-, and 3-year actuarial rates of maintaining serviceable hearing were 93%, 77%, and 74%, respectively. No patient who received a mean cochlear dose less than 2 Gy experienced serviceable hearing loss (p = 0.035). Patients who received a mean cochlear dose less than 3 Gy had a 2-year hearing preservation rate of 91% compared with 59% in those who received a mean cochlear dose of 3 Gy or greater (p = 0.029). Those who had more than 25% of their cochlea receiving 3 Gy or greater had a higher rate of hearing loss (p = 0.030). There was no statistically significant correlation between serviceable hearing loss and age, tumor size, pre-GKS PTA, pre-GKS SD, pre-GKS Gardner-Robertson class, maximum cochlear dose, or the percentage of cochlear volume receiving 5 Gy. On multivariate analysis there was a trend toward significance for serviceable hearing loss with a mean cochlear dose of 3 Gy or greater (p = 0.074). Local control was 100% at 24 months. No patient developed facial or trigeminal nerve dysfunction. Conclusions With a median mean cochlear dose of 2.7 Gy, the majority of patients with serviceable hearing retained serviceable hearing 3 years after GKS. A mean cochlear dose less than 3 Gy was associated with higher serviceable hearing preservation.

Download Full-text

GAMMA KNIFE RADIOSURGERY IN YOUNGER PATIENTS WITH VESTIBULAR SCHWANNOMAS

Neurosurgery ◽

10.1227/01.neu.0000345944.14065.35 ◽

2009 ◽

Vol 65 (2) ◽

pp. 294-301 ◽

Cited By ~ 61

Author(s):

Javier Lobato-Polo ◽

Douglas Kondziolka ◽

Oscar Zorro ◽

Hideyuki Kano ◽

John C. Flickinger ◽

...

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Gamma Knife Radiosurgery ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Surgical Removal ◽

Management Options ◽

Younger Patients ◽

Cranial Nerve Dysfunction

Abstract OBJECTIVE Management options for patients with vestibular schwannoma include observation, surgical resection, stereotactic radiosurgery (SRS), and stereotactic radiation therapy. In younger patients, resection is often advocated because of concern regarding the long-term effects of radiation. We studied tumor response and clinical outcomes after SRS in such patients. METHODS We reviewed long-term outcomes in 55 patients with vestibular schwannomas. Patients were 40 years of age or younger, underwent gamma knife (GK) SRS between 1987 and 2003, and were followed up for a minimum of 4 years. The median patient age was 35 years (range, 13–40 years). Forty-one patients had Gardner-Robertson class 1 to 4 hearing. Thirteen patients (24%) had undergone surgical removal. The median tumor volume was 1.7 mm3. The median tumor margin dose was 13.0 Gy (range, 11–20 Gy). RESULTS At a median of 5.3 years, (range, 4–20 years), 2 of 55 patients underwent GK SRS for a second time; 1 of these patients had had a recurrence after initial resection. The 5-year rate of freedom from additional management was 96%. Hearing preservation rates (i.e., remaining within the same Gardner-Robertson hearing class) were 93%, 87%, and 87% at 3, 5, and 10 years, respectively. In patients with serviceable hearing before SRS, it was maintained in 100%, 93%, and 93% of patients at 3, 5, and 10 years, respectively. Hearing preservation was related to a margin dose lower than 13 Gy (P = 0.017). At the last assessment, facial and trigeminal nerve function was preserved in 98.2% and 96.4% of patients, respectively; the only facial deficit (House-Brackmann grade III) occurred in a patient who received a tumor dose of 20 Gy early in our experience (1988). None of the patients treated with doses lower than 13 Gy experienced facial or trigeminal neuropathy. All patients continued their previous level of activity or employment after GK SRS. No patient developed a secondary radiation-related tumor. CONCLUSION Our experience indicates that GK SRS is an effective management strategy for younger patients with vestibular schwannoma, most of whom have no additional cranial nerve dysfunction.

Download Full-text

Increased preservation of functional hearing after gamma knife surgery for vestibular schwannoma

Journal of Neurosurgery ◽

10.3171/jns.2005.102.s_supplement.0204 ◽

2005 ◽

Vol 102 ◽

pp. 204-206 ◽

Cited By ~ 31

Author(s):

Albertus T. C. J. van Eck ◽

Gerhard A. Horstmann

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Maximum Dose ◽

Hearing Preservation ◽

Gamma Knife Surgery ◽

Tumor Control ◽

Content Type ◽

Second Procedure ◽

Fine Print

Object.Gamma knife surgery (GKS) for vestibular schwannoma is still associated with an additional hearing loss of approximately 30%. The purpose of this study was to record the effect on hearing preservation of maintaining a margin dose of 13 Gy while reducing the maximum dose to 20 Gy.Methods.Seventy-eight of 95 patients who entered a prospective protocol with a follow up of at least 12 months (mean 22 months) were evaluated. The mean tumor volume was 2.28 cm3. After a mean follow-up duration of 22 months, the magnetic resonance imaging—based tumor control rate was 87%. In two cases a second procedure (surgery) was necessary. Thus, the clinical control rate was 97.5%. In two cases there was an increase in trigeminal dysesthesia. One patient suffered transient facial nerve impairment. Functional hearing was preserved in 83.4% of the patients with functional hearing preoperatively.Conclusions.Reducing the maximum dose to 20 Gy seems to be an effective treatment, which probably increases preservation of functional hearing without sacrificing the high tumor control rates achieved in radiosurgery. Post-radiosurgery tumor swelling occurred in 25% of the cases and was not correlated with hearing deterioration.

Download Full-text

Hearing Preservation in Patients with Unilateral Vestibular Schwannoma after Gamma Knife Surgery

Progress in Neurological Surgery - Modern Management of Acoustic Neuroma ◽

10.1159/000156901 ◽

2008 ◽

pp. 142-151 ◽

Cited By ~ 43

Author(s):

Jean Régis ◽

Manabu Tamura ◽

Christine Delsanti ◽

Pierre-Hugues Roche ◽

William Pellet ◽

...

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Hearing Preservation ◽

Gamma Knife Surgery

Download Full-text

Increased preservation of functional hearing after gamma knife surgery for vestibular schwannoma

Journal of Neurosurgery ◽

10.3171/sup.2005.102.s_supplement.0204 ◽

2005 ◽

Vol 102 (Special_Supplement) ◽

pp. 204-206 ◽

Cited By ~ 9

Author(s):

Albertus T. C. J. van Eck ◽

Gerhard A. Horstmann

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Maximum Dose ◽

Hearing Preservation ◽

Gamma Knife Surgery ◽

Tumor Control ◽

Content Type ◽

Second Procedure ◽

Fine Print

Object. Gamma knife surgery (GKS) for vestibular schwannoma is still associated with an additional hearing loss of approximately 30%. The purpose of this study was to record the effect on hearing preservation of maintaining a margin dose of 13 Gy while reducing the maximum dose to 20 Gy. Methods. Seventy-eight of 95 patients who entered a prospective protocol with a follow up of at least 12 months (mean 22 months) were evaluated. The mean tumor volume was 2.28 cm3. After a mean follow-up duration of 22 months, the magnetic resonance imaging—based tumor control rate was 87%. In two cases a second procedure (surgery) was necessary. Thus, the clinical control rate was 97.5%. In two cases there was an increase in trigeminal dysesthesia. One patient suffered transient facial nerve impairment. Functional hearing was preserved in 83.4% of the patients with functional hearing preoperatively. Conclusions. Reducing the maximum dose to 20 Gy seems to be an effective treatment, which probably increases preservation of functional hearing without sacrificing the high tumor control rates achieved in radiosurgery. Post-radiosurgery tumor swelling occurred in 25% of the cases and was not correlated with hearing deterioration.

Download Full-text

Hearing Preservation after Gamma Knife Surgery in Patients with Vestibular Schwannoma

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0032-1314170 ◽

2012 ◽

Vol 73 (S 02) ◽

Author(s):

H. Hammami ◽

R. Kania ◽

D. Bresson ◽

S. Froelich ◽

E. Sauvaget ◽

...

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Hearing Preservation ◽

Gamma Knife Surgery

Download Full-text

Assessing the Long-term Safety and Efficacy of Gamma Knife and Linear Accelerator Radiosurgery for Vestibular Schwannoma: A Systematic Review and Meta-analysis

Neuro-Oncology Practice ◽

10.1093/nop/npab052 ◽

2021 ◽

Author(s):

Sergio W Guadix ◽

Alice J Tao ◽

Anjile An ◽

Michelle Demetres ◽

Umberto Tosi ◽

...

Keyword(s):

Gamma Knife ◽

Trigeminal Nerve ◽

Vestibular Schwannoma ◽

Linear Accelerator ◽

Meta Analysis ◽

Hearing Preservation ◽

Tumor Control ◽

Nerve Function ◽

Safety And Efficacy

Abstract Background Differences in long-term outcomes of single-fraction stereotactic radiosurgery (SRS) between Gamma Knife (GK) and Linear Accelerator (LINAC) systems for vestibular schwannoma (VS) management remain unclear. To investigate differences in safety and efficacy between modalities, we conducted a meta-analysis of studies over the past decade. Methods MEDLINE, EMBASE, and Cochrane databases were queried for studies with the following inclusion criteria: English-language, published between January 2010—April 2020, cohort size ≥ 30, and mean/median follow-up ≥ 5 years. Odds ratios (OR) compared rates of tumor control, hearing preservation, and cranial nerve toxicities before and after SRS. Results Thirty-nine studies were included (29 GK, 10 LINAC) with 6,516 total patients. Tumor control rates were 93% (95% CI 91-94%) and 94% (95% CI 91-97%) for GK and LINAC, respectively. Both GK (OR 0.06, 95% CI 0.02-0.13) and LINAC (OR 0.47, 95% CI 0.29-0.76) reduced odds of serviceable hearing. Neither GK (OR 0.71, 95% CI 0.41-1.22) nor LINAC (OR 1.13, 95% CI 0.64-2.00) impacted facial nerve function. GK decreased odds of trigeminal nerve impairment (OR 0.55, 95% CI 0.32-0.94) while LINAC did not impact trigeminal nerve function (OR 1.45, 95% CI 0.81-2.61). Lastly, LINAC offered decreased odds of tinnitus (OR 0.15, 95% CI 0.03-0.87) not observed with GK (OR 0.70, 95% CI 0.48-1.01). Conclusions VS tumor control and hearing preservation rates are comparable between GK and LINAC SRS. GK may better preserve trigeminal nerve function, while LINAC decreases tinnitus rates. Future studies are warranted to investigate the efficacy of GK and LINAC SRS more directly.

Download Full-text

Factors associated with hearing preservation after Gamma Knife surgery for vestibular schwannomas in patients who retain serviceable hearing

Journal of Neurosurgery ◽

10.3171/2011.7.jns11749 ◽

2011 ◽

Vol 115 (6) ◽

pp. 1078-1086 ◽

Cited By ~ 72

Author(s):

Toshinori Hasegawa ◽

Yoshihisa Kida ◽

Takenori Kato ◽

Hiroshi Iizuka ◽

Takashi Yamamoto

Keyword(s):

Mr Imaging ◽

Gamma Knife ◽

Hearing Preservation ◽

Gamma Knife Surgery ◽

Class I ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Control Factors ◽

Number Of Patients

Object Gamma Knife surgery (GKS) has been a safe and effective treatment for small- to medium-sized vestibular schwannomas (VSs) over relatively long-term outcomes. However, even with recent radiosurgical techniques, hearing results following GKS remain unsatisfactory. The purpose of this study was to evaluate the hearing preservation rate as well as factors related to hearing preservation in patients with VSs and serviceable hearing who were treated with GKS. Methods Among patients with Gardner-Robertson (GR) Class I or II serviceable hearing and VSs treated with GKS between 1991 and 2009, 117 were evaluable via periodic MR imaging and audiometry. Results The median age at the time of GKS was 52 years. Four patients (3%) had undergone prior surgery. Fifty-six patients (48%) had GR Class I hearing and 61 (52%) had GR Class II hearing at the time of GKS. The median tumor volume was 1.9 cm3. The median maximum and tumor margin radiation doses were 24 and 12 Gy, respectively. The median follow-up periods for MR imaging and audiometry were 74 and 38 months, respectively. The overall tumor control rate was 97.5%. Actuarial 3-, 5-, and 8-year hearing preservation rates were 55%, 43%, and 34%, respectively. On multivariate analysis, GR hearing class at the time of GKS and the mean cochlear dose affected hearing preservation significantly. In a limited number of patients who were treated using the most recent dose planning techniques and who had GR Class I hearing before treatment, the 3- and 5-year hearing preservation rates increased to 80% and 70%, respectively. Conclusions For the majority of patients with small- to medium-sized VSs, GKS was an effective and reasonable alternative to resection with satisfactory long-term tumor control. Factors related to hearing preservation included a GR Class I hearing pre-GKS and a lower mean cochlear radiation dose. To retain serviceable hearing, it is important to apply GKS treatment while patients retain GR Class I hearing.

Download Full-text

Long-term follow-up studies of Gamma Knife surgery with a low margin dose for vestibular schwannoma

Journal of Neurosurgery ◽

10.3171/2012.7.gks12783 ◽

2012 ◽

Vol 117 (Special_Suppl) ◽

pp. 57-62 ◽

Cited By ~ 21

Author(s):

Shibin Sun ◽

Ali Liu

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Facial Palsy ◽

Gamma Knife Surgery ◽

Tumor Control ◽

Trigeminal Neuropathy ◽

Brainstem Compression ◽

Long Term Follow Up

Object The aim of this study was to assess long-term clinical outcomes in patients who underwent Gamma Knife surgery (GKS) with a low margin dose—14 Gy or less—to treat vestibular schwannoma (VS) unrelated to neurofibromatosis Type II. Methods Between December 1994 and December 2001, 200 patients with VSs underwent GKS, which was performed using the Leksell Gamma Knife model B. More than 10 years of follow-up is available in these patients. One hundred ninety patients (88 male and 102 female patients) were followed up using MRI (follow-up rate 95%). The mean age of these patients was 50.6 years (range 10–77 years). Gamma Knife surgery was the primary treatment for VS in 134 cases (70.5%) and was an adjunctive management approach in 56 cases (29.5%). The median tumor margin dose was 13.0 Gy (range 6.0–14.4 Gy), and the median maximum tumor dose was 28.0 Gy (range 15.0–60.0 Gy). The median tumor volume was 3.6 cm3 (range 0.3–27.3 cm3). The median duration of follow-up in these patients was 109 months (range 8–195 months). Results In the 190 patients, the latest follow-up MRI studies demonstrated tumor regression in 122 patients (64.2%), stable tumor in 48 patients (25.3%), and tumor enlargement in 20 patients (10.5%). The total rate of tumor control was 89.5%. Using the Kaplan-Meier method, the authors found the estimated 3-, 5-, 10-, and 15-year tumor control rates to be 95%, 93%, 86%, and 79%, respectively; and the estimated 3-, 5-, and 10-year hearing preservation rates to be 96%, 92%, and 70%, respectively. Twenty-six patients (13.7%) exhibited transient mild facial palsy or facial spasm, and 2 patients (1.1%) suffered persistent mild facial palsy. Thirty-nine patients (20.5%) had transient trigeminal neuropathy, and 5 patients (2.6%) suffered from persistent mild facial numbness. The incidence of persistent severe facial and trigeminal neuropathy was 0.0%. Conclusions With a low prescribed margin dose of 14 Gy or less, GKS was confirmed to provide long-term tumor control for small to medium-sized VSs and largely to prevent cranial nerves from iatrogenic injury. Based on the findings of this study, GKS is also a reasonable option for the treatment of large, heterogeneously enhancing tumors without symptomatic brainstem compression. Gamma Knife surgery can preserve a high quality of life for most patients with VS who do not have symptomatic brainstem compression. Long-term follow-up is required because of the risk of delayed recurrence of VS.

Download Full-text