Meta-analysis of tumor control rates in patients undergoing stereotactic radiosurgery for cystic vestibular schwannomas

Abstract INTRODUCTION Cystic vestibular schwannomas (VS) represent a subtype that grows more rapidly due to expansion of cystic contents and are important candidates for stereotactic radiosurgery (SRS) intervention due to their tendency to adhere to the neurovasculature. However, the paucity of comprehensive outcomes data is currently a limiting factor to understanding the potential of using SRS to treat cystic VS. METHODS This study was conducted in accordance with the PRISMA guidelines. A search was conducted in October 2018 through the PubMed, Scopus, Embase, Web of Science, and Cochrane databases. Data on tumor control rates were extracted and analyzed using meta-analysis and tests for heterogeneity between articles, with the t2, Cochran's Q, and I2 statistics reported. Publication bias was assessed using funnel plots and Egger's testing. RESULTS A total of 246 patients underwent SRS for cystic VS, with reported mean or median follow-up of 49.7 to 150 mo. Following SRS treatment for cystic VS across all studies, 92% of patients had tumor control at follow up, (95%-CI: 88%-95%). In studies that specifically reported tumor control rate at 5 yr, control rate was also 92% (95%-CI: 87%-95%). Tumor control rate specifically for patients who underwent GammaKnife was 93% (95%-CI: 88%-95%). CONCLUSION Results of our meta-analysis suggest that SRS is a viable treatment option for cystic VS, exhibiting effective tumor control rates. Despite the paucity of pertinent data, our conclusions provide evidence in contrast to the initial impressions of SRS treatment for cystic VS within the neurosurgical community.

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RADT-16. HYPOFRACTIONATED RADIOTHERAPY AND STEREOTACTIC RADIOSURGERY FOR VESTIBULAR SCHWANNOMAS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.769 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii184-ii185

Author(s):

Umberto Tosi ◽

Sergio Guadix ◽

Anjile An ◽

Drew Wright ◽

Andrew Brandmaier ◽

...

Keyword(s):

Facial Nerve ◽

Stereotactic Radiosurgery ◽

Cranial Nerve ◽

Meta Analysis ◽

Post Treatment ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Significant Heterogeneity ◽

Ovid Medline ◽

Cochrane Reviews

Abstract BACKGROUND Vestibular schwannomas (VS) are tumors of the cerebellopontine angle with significant morbidity, causing hearing loss, tinnitus, and trigeminal and facial nerve compromise. Surgical resection is complex and often results in comorbidities, with radiation therapy being used to achieve tumor control. Both single dose stereotactic radiosurgery (SRS) and, in recent years, hypofractionated stereotactic radiotherapy (hSRT), where a total 18-25 Gy dose is given in approximately 3-5 fractions, have been utilized. It remains unclear, however, how each of these approaches fares compared to the other. METHODS Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Reviews were searched for studies either comparing hSRT with SRS or focusing on hSRT alone for the treatment of VS. Primary endpoints included tumor control, serviceable hearing, presence of tinnitus, and facial and trigeminal nerve symptoms. A random effects analysis was employed to compare pre- and post-treatment effects (hSRT alone) or SRS and hSRT outcomes (two-arm studies). RESULTS This analysis included 21 studies focusing on hSRT alone and 13 studies comparing SRS and hSRT. Significant heterogeneity was observed. Overall, when hSRT was analyzed alone, crude tumor control was achieved in 93% of 1571 patients at average follow-up of 49.9 months. There was no difference intra-group between pre- and post-treatment odds ratios (OR) of tinnitus, facial, or trigeminal impairment. However, serviceable hearing was diminished following hSRT (OR = 0.60, 95% CI: 0.44, 0.83, p = 0.002). Comparison with SRS showed no difference with respect to tumor control (p = 0.84), serviceable hearing (p = 0.65), trigeminal impairment (p = 0.96), or facial nerve impairment (p = 0.32). CONCLUSIONS hSRT achieved excellent tumor control and, with the exception of serviceable hearing, did not result in worse cranial nerve symptomatology. Analyzing two-arm studies showed that hSRT is a treatment modality comparable to SRS with respect to tumor control and cranial nerve comorbidities.

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Outcomes of Stereotactic Radiosurgery for Large Vestibular Schwannomas: a Systematic Review and Meta-Analysis

Neuro-Oncology Practice ◽

10.1093/nop/npab011 ◽

2021 ◽

Author(s):

Umberto Tosi ◽

Miguel E Tusa Lavieri ◽

Anjile An ◽

Omri Maayan ◽

Sergio W Guadix ◽

...

Keyword(s):

Facial Nerve ◽

Stereotactic Radiosurgery ◽

Cranial Nerve ◽

Meta Analysis ◽

Management Strategies ◽

Treatment Protocol ◽

Vestibular Schwannomas ◽

Treatment Modalities ◽

Tumor Control ◽

Pre Treatment

Abstract Background Large vestibular schwannomas (VS) pose a treatment challenge for both microsurgery (MS) and stereotactic radiosurgery (SRS). Technical developments have allowed for safer irradiation of large tumors. It remains unclear if SRS can achieve appropriate tumor control and acceptable cranial nerve toxicities. In this study, we assess outcomes of irradiation for large VS. Methods PubMed MEDLINE, EMBASE, Web of Science, and Cochrane were searched for all the studies assessing SRS outcome in large VS. Primary endpoints included clinical and radiographic tumor control, need for salvage surgery, serviceable hearing, cranial nerve V and VII impairment, presence of hydrocephalus requiring shunting, and presence of vertigo / dizziness. Results 22 studies were identified that met selection criteria for analysis from an initial pool of 1272 reports. They were evaluated according to treatment protocol: (i) single dose SRS (13 studies, 483 patients), (ii) combination of MS and SRS (7 studies, 182 patients), and (iii) fractionated SRS (3 studies, 82 patients). Tumor control was achieved in 89%, 94%, and 91% of patients, respectively. Odds ratio of post- over pre-treatment serviceable hearing were 0.42 (p < 0.01), 0.47 (p = 0.05), and 0.60 (p = 0.22); for facial nerve impairment, these OR were 1.08 (p = 0.69), 3.45 (p = 0.28), and 0.87 (p = 0.71) respectively. Conclusions The management of large VS remains challenging. All treatment modalities resulted in high tumor control rates and worsening of pre-treatment hearing. None, however, caused significant facial nerve impairment, suggesting that management strategies incorporating focal irradiation can be successful.

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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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Repeat stereotactic radiosurgery for progressive vestibular schwannomas after previous radiosurgery: a systematic review and meta-analysis

Neurosurgical Review ◽

10.1007/s10143-021-01528-y ◽

2021 ◽

Author(s):

Anne Balossier ◽

Jean Régis ◽

Nicolas Reyns ◽

Pierre-Hugues Roche ◽

Roy Thomas Daniel ◽

...

Keyword(s):

Systematic Review ◽

Hearing Loss ◽

Facial Nerve ◽

Stereotactic Radiosurgery ◽

Cranial Nerve ◽

Meta Analysis ◽

Cranial Nerves ◽

Vestibular Schwannomas ◽

Benign Tumors ◽

Tumor Control

AbstractVestibular schwannomas (VS) are slow-growing intracranial extraaxial benign tumors, developing from the vestibular part of the eight cranial nerves. Stereotactic radiosurgery (SRS) has now a long-term scientific track record as first intention treatment for small- to medium-sized VS. Though its success rate is very high, SRS for VS might fail to control tumor growth in some cases. However, the literature on repeat SRS after previously failed SRS remains scarce and reported in a low number of series with a limited number of cases. Here, we aimed at performing a systematic review and meta-analysis of the literature on repeat SRS for VS. Using PRISMA guidelines, we reviewed manuscripts published between January 1990 and October 2020 and referenced in PubMed. Tumor control and cranial nerve outcomes were evaluated with separate meta-analyses. Eight studies comprising 194 patients were included. The overall rate of patients treated in repeat SRS series as per overall series with first SRS was 2.2% (range 1.2–3.2%, p < 0.001). The mean time between first and second SRS was 50.7 months (median 51, range 44–64). The median marginal dose prescribed at first SRS was 12 Gy (range 8–24) and at second SRS was 12 Gy (range 9.8–19). After repeat SRS, tumor stability was reported in 61/194 patients, i.e., a rate of 29.6% (range 20.2–39%, I2 = 49.1%, p < 0.001). Tumor decrease was reported in 83/194 patients, i.e., a rate of 54.4% (range 33.7–75.1%, I2 = 89.1%, p < 0.001). Tumor progression was reported in 50/188 patients, i.e., a rate of 16.1% (range 2.5–29.7%, I2 = 87.1%, p = 0.02), rarely managed surgically. New trigeminal numbness was reported in 27/170 patients, i.e., a rate of 9.9% (range 1.4–18.3%, p < 0.02). New facial nerve palsy of worsened of previous was reported in 8/183 patients, i.e., a rate of 4.3% (range 1.4–7.2%, p = 0.004). Hearing loss was reported in 12/22 patients, i.e., a rate of 54.3% (range 24.8–83.8%, I2 = 70.7%, p < 0.001). Repeat SRS after previously failed SRS for VS is associated with high tumor control rates. Cranial nerve outcomes remain favorable, particularly for facial nerve. The rate of hearing loss appears similar to the one related to first SRS.

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Stereotactic radiosurgery as the first-line treatment for intracanalicular vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2020.9.jns202818 ◽

2021 ◽

pp. 1-7

Author(s):

Akiyoshi Ogino ◽

L. Dade Lunsford ◽

Hao Long ◽

Stephen Johnson ◽

Andrew Faramand ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Observation Interval ◽

Univariate Analysis ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Line Treatment ◽

First Line ◽

Additional Intervention ◽

First Line Treatment

OBJECTIVEThis report evaluates the outcomes of stereotactic radiosurgery (SRS) as the first-line treatment of intracanalicular vestibular schwannomas (VSs).METHODSBetween 1987 and 2017, the authors identified 209 patients who underwent SRS as the primary intervention for a unilateral intracanalicular VS. The median patient age was 54 years (range 22–85 years); 94 patients were male and 115 were female. Three patients had facial neuropathy at the time of SRS. One hundred fifty-five patients (74%) had serviceable hearing (Gardner-Robertson [GR] grades I and II) at the time of SRS. The median tumor volume was 0.17 cm3 (range 0.015–0.63 cm3). The median margin dose was 12.5 Gy (range 11.0–25.0 Gy). The median maximum dose was 24.0 Gy (range 15.7–50.0 Gy).RESULTSThe progression-free survival rates of all patients with intracanalicular VS were 97.5% at 3 years, 95.6% at 5 years, and 92.1% at 10 years. The rates of freedom from the need for any additional intervention were 99.4% at 3 years, 98.3% at 5 years, and 98.3% at 10 years. The serviceable hearing preservation rates in GR grade I and II patients at the time of SRS were 76.6% at 3 years, 63.5% at 5 years, and 27.3% at 10 years. In univariate analysis, younger age (< 55 years, p = 0.011), better initial hearing (GR grade I, p < 0.001), and smaller tumor volumes (< 0.14 cm3, p = 0.016) were significantly associated with improved hearing preservation. In multivariate analysis, better hearing (GR grade I, p = 0.001, HR 2.869, 95% CI 1.569–5.248) and smaller tumor volumes (< 0.14 cm3, p = 0.033, HR 2.071, 95% CI 1.059–4.047) at the time of SRS were significantly associated with improved hearing preservation. The hearing preservation rates of patients with GR grade I VS were 88.1% at 3 years, 77.9% at 5 years, and 38.1% at 10 years. The hearing preservation rates of patients with VSs smaller than 0.14 cm3 were 85.5% at 3 years, 77.7% at 5 years, and 42.6% at 10 years. Facial neuropathy developed in 1.4% from 6 to 156 months after SRS.CONCLUSIONSSRS provided sustained tumor control in more than 90% of patients with intracanalicular VS at 10 years and freedom from the need for additional intervention in more than 98% at 10 years. Patients with initially better hearing and smaller VSs had enhanced serviceable hearing preservation during an observation interval up to 10 years after SRS.

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Stereotactic Radiosurgery as Primary Treatment in Fast-Growing Vestibular Schwannomas: A Meta-analysis

10.1055/s-0041-1725397 ◽

2021 ◽

Author(s):

Leanne O. Hamilton ◽

Constantina Yiannakis ◽

Afiq Slim ◽

Georgios Kontorinis

Keyword(s):

Stereotactic Radiosurgery ◽

Meta Analysis ◽

Primary Treatment ◽

Vestibular Schwannomas ◽

Fast Growing

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Tumor control and trigeminal dysfunction improvement after stereotactic radiosurgery for trigeminal schwannomas: a systematic review and meta-analysis

Neurosurgical Review ◽

10.1007/s10143-020-01433-w ◽

2020 ◽

Author(s):

Iulia Peciu-Florianu ◽

Jean Régis ◽

Marc Levivier ◽

Michaela Dedeciusova ◽

Nicolas Reyns ◽

...

Keyword(s):

Trigeminal Neuralgia ◽

Tumor Progression ◽

Stereotactic Radiosurgery ◽

Clinical Outcomes ◽

Meta Analysis ◽

Symptomatic Improvement ◽

Tumor Control ◽

Linear Accelerators ◽

Oculomotor Nerves ◽

Clinical Worsening

AbstractTrigeminal nerve schwannomas (TS) are uncommon intracranial tumors, frequently presenting with debilitating trigeminal and/or oculomotor nerve dysfunction. While surgical resection has been described, its morbidity and mortality rates are non-negligible. Stereotactic radiosurgery (SRS) has emerged with variable results as a valuable alternative. Here, we aimed at reviewing the medical literature on TS treated with SRS so as to investigate rates of tumor control and symptomatic improvement. We reviewed manuscripts published between January 1990 and December 2019 on PubMed. Tumor control and symptomatic improvement rates were evaluated with separate meta-analyses. This meta-analysis included 18 studies comprising a total of 564 patients. Among them, only one reported the outcomes of linear accelerators (Linac), while the others of GK. Tumor control rates after SRS were 92.3% (range 90.1–94.5; p < 0.001), and tumor decrease rates were 62.7% (range 54.3–71, p < 0.001). Tumor progression rates were 9.4% (range 6.8–11.9, p < 0.001). Clinical improvement rates of trigeminal neuralgia were 63.5% (52.9–74.1, p < 0.001) and of oculomotor nerves were 48.2% (range 36–60.5, p < 0.001). Clinical worsening rate was 10.7% (range 7.6–13.8, p < 0.001). Stereotactic radiosurgery for TS is associated with high tumor control rates and favorable clinical outcomes, especially for trigeminal neuralgia and oculomotor nerves. However, patients should be correctly advised about the risk of tumor progression and potential clinical worsening. Future clinical studies should focus on standard reporting of clinical outcomes.

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Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas – A Retrospective Cohort Study

Otology & Neurotology ◽

10.1097/mao.0000000000003285 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Peter L. Santa Maria ◽

Yangyang Shi ◽

Ksenia A. Aaron ◽

Richard K. Gurgel ◽

C. Eduardo Corrales ◽

...

Keyword(s):

Cohort Study ◽

Stereotactic Radiosurgery ◽

Retrospective Cohort Study ◽

Retrospective Cohort ◽

Vestibular Schwannomas ◽

Tumor Control

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

Journal of Neurosurgery ◽

10.3171/2016.7.gks161494 ◽

2016 ◽

Vol 125 (Supplement_1) ◽

pp. 64-72 ◽

Cited By ~ 34

Author(s):

Shinya Watanabe ◽

Masaaki Yamamoto ◽

Takuya Kawabe ◽

Takao Koiso ◽

Tetsuya Yamamoto ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Tumor Volume ◽

Hearing Preservation ◽

Interquartile Range ◽

Vestibular Schwannomas ◽

Long Term Results ◽

Tumor Control ◽

Univariable Analysis

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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