Preserving normal facial nerve function and improving hearing outcome in large vestibular schwannomas with a combined approach: planned subtotal resection followed by gamma knife radiosurgery

Object The response rate of vestibular schwannomas (VSs) to radiosurgery has reached the 97% level in several published series. When failure rarely occurs, some controversy has existed as to whether the tumor has to be resected or can be safely retreated with radiosurgery. The authors retrospectively studied the outcome of retreating 11 patients with Gamma Knife surgery (GKS). Methods The authors studied 11 patients at the New England Gamma Knife Center who had undergone GKS as a second radiosurgical treatment for VS from 1994 to 2007. One patient underwent proton-beam radiotherapy as the first treatment, and the other 10 patients had undergone GKS initially. Tumor control (size before and after the first and the second treatment) was evaluated using MR imaging to demonstrate the course after the 2 treatments. Facial nerve function (House–Brackmann grading system), trigeminal nerve function, hearing (Gardner–Robertson classification), and any adverse radiation effects were evaluated. The prescription dose was 12 Gy (11–13.2 Gy) for both treatments. Results Of the 11 patients, 2 showed increase, 1 had no change, and, in 8, the VS decreased in size after the retreatment. One tumor remained unchanged over the first 6 months, but demonstrated signs of internal necrosis. All patients demonstrated stable facial nerve function. Regarding facial numbness, 2 patients experienced increases, 8 no change, and 1 decreased numbness. There was no functional hearing prior to the second treatment in 10 patients, and hearing was impaired in 1 patient. Adverse radiation effects (slight peduncular edema) were seen in 2 patients after the second treatment, and 1 patient had edema after the first treatment as well. Conclusions Vestibular schwannomas can be retreated with GKS with good tumor control response and low risk of toxicity.

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The behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2014.2.jns131497 ◽

2014 ◽

Vol 120 (6) ◽

pp. 1278-1287 ◽

Cited By ~ 43

Author(s):

Zhengnong Chen ◽

Sampath Chandra Prasad ◽

Filippo Di Lella ◽

Marimar Medina ◽

Enrico Piccirillo ◽

...

Keyword(s):

Facial Nerve ◽

Residual Tumor ◽

Vestibular Schwannomas ◽

Subtotal Resection ◽

Nerve Function ◽

Facial Nerve Function ◽

Incomplete Excision ◽

Kaplan Meier ◽

Tumor Regrowth

Object The authors evaluated the behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas (VSs). Methods The case records of all patients who underwent surgical treatment of VSs were analyzed. All patients in whom an incomplete excision had been performed were analyzed. Incomplete excision was defined as near-total resection (NTR), subtotal resection (STR), and partial resection (PR). Tumors in the NTR and STR categories were followed up with a wait-and-rescan approach, whereas the tumors in the PR category were subjected to a second-stage surgery and were excluded from this series. All patients included in the study underwent baseline MRI at the 3rd and 12th postoperative months, and repeat imaging was subsequently performed every year for 7–10 years postoperatively or as indicated clinically. Preoperative and postoperative facial function was noted. Results Of the 2368 patients who underwent surgery for VS, 111 patients who had incomplete excisions of VSs were included in the study. Of these patients, 73 (65.77%) had undergone NTR and 38 (34.23%) had undergone STR. Of the VSs, 62 (55.86%) were cystic and 44 (70.97%) of these cystic VSs underwent NTR. The residual tumor was left behind on the facial nerve alone in 62 patients (55.86%), on the facial nerve and vessels in 2 patients (1.80%), on the facial nerve and brainstem in 15 patients (13.51%), and on the brainstem alone in 25 patients (22.52%). In the 105 patients with normal preoperative facial nerve function, postoperative facial nerve function was House-Brackmann (HB) Grades I and II in 51 patients (48.57%), HB Grade III in 34 patients (32.38%), and HB Grades IV–VI in 20 patients (19.05%). Seven patients (6.3%) showed evidence of tumor regrowth on follow-up MRI. All 7 patients (100%) who showed evidence of tumor regrowth had undergone STR. No patient in the NTR group exhibited regrowth. The Kaplan-Meier plot demonstrated a 5-year tumor regrowth-free survival of 92%, with a mean disease-free interval of 140 months (95% CI 127–151 months). The follow-up period ranged from 12 to 156 months (mean 45.4 months). Conclusions The authors' report and review of the literature show that there is undoubtedly merit for NTR and STR for preservation of the facial nerve. On the basis of this they propose an algorithm for the management of incomplete VS excisions. Patients who undergo incomplete excisions must be subjected to follow-up MRI for a period of at least 7–10 years. When compared with STR, NTR via an enlarged translabyrinthine approach has shown to have a lower rate of regrowth of residual tumor, while having almost the same result in terms of facial nerve function.

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Gamma Knife radiosurgery for facial nerve schwannomas: a multicenter study

Journal of Neurosurgery ◽

10.3171/2014.11.jns141160 ◽

2015 ◽

Vol 123 (2) ◽

pp. 387-394 ◽

Cited By ~ 11

Author(s):

Jason P. Sheehan ◽

Hideyuki Kano ◽

Zhiyuan Xu ◽

Veronica Chiang ◽

David Mathieu ◽

...

Keyword(s):

Facial Nerve ◽

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Gamma Knife Radiosurgery ◽

Rank Test ◽

Tumor Control ◽

Nerve Function ◽

Facial Nerve Function ◽

Log Rank Test

OBJECT Facial nerve schwannomas (FNSs) are rare intracranial tumors, and the optimal management of these tumors remains unclear. Resection can be undertaken, but the tumor’s intimate association with the facial nerve makes resection with neurological preservation quite challenging. Stereotactic radiosurgery (SRS) has been used to treat FNSs, and this study evaluates the outcome of this approach. METHODS At 8 medical centers participating in the North American Gamma Knife Consortium (NAGKC), 42 patients undergoing SRS for an FNS were identified, and clinical and radiographic data were obtained for these cases. Males outnumbered females at a ratio of 1.2:1, and the patients’ median age was 48 years (range 11–76 years). Prior resection was performed in 36% of cases. The mean tumor volume was 1.8 cm3, and a mean margin dose of 12.5 Gy (range 11–15 Gy) was delivered to the tumor. RESULTS At a median follow-up of 28 months, tumor control was achieved in 36 (90%) of the 40 patients with reliable radiographic follow-up. Actuarial tumor control was 97%, 97%, 97%, and 90% at 1, 2, 3, and 5 years postradiosurgery. Preoperative facial nerve function was preserved in 38 of 42 patients, with 60% of evaluable patients having House-Brackmann scores of 1 or 2 at last follow-up. Treated patients with a House-Brackmann score of 1 to 3 were more likely to demonstrate this level of facial nerve function at last evaluation (OR 6.09, 95% CI 1.7–22.0, p = 0.006). Avoidance of temporary or permanent neurological symptoms was more likely to be achieved in patients who received a tumor margin dose of 12.5 Gy or less (log-rank test, p = 0.024) delivered to a tumor of ≤ 1 cm3 in volume (log-rank test, p = 0.01). CONCLUSIONS Stereotactic radiosurgery resulted in tumor control and neurological preservation in most FNS patients. When the tumor is smaller and the patient exhibits favorable normal facial nerve function, SRS portends a better result. The authors believe that early, upfront SRS may be the treatment of choice for small FNSs, but it is an effective salvage treatment for residual/recurrent tumor that remain or progress after resection.

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Outcomes of large vestibular schwannomas following subtotal resection: early post-operative volume regression and facial nerve function

Journal of Neuro-Oncology ◽

10.1007/s11060-019-03157-4 ◽

2019 ◽

Vol 143 (2) ◽

pp. 281-288 ◽

Cited By ~ 6

Author(s):

Oluwaseun O. Akinduro ◽

Larry B. Lundy ◽

Alfredo Quinones-Hinojosa ◽

Victor M. Lu ◽

Daniel M. Trifiletti ◽

...

Keyword(s):

Facial Nerve ◽

Vestibular Schwannomas ◽

Subtotal Resection ◽

Nerve Function ◽

Facial Nerve Function

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Immediate neurological deterioration after gamma knife radiosurgery for acoustic neuroma

Journal of Neurosurgery ◽

10.3171/jns.2000.93.supplement_3.0078 ◽

2000 ◽

Vol 93 (supplement_3) ◽

pp. 78-81 ◽

Cited By ~ 13

Author(s):

Masao Tago ◽

Atsuro Terahara ◽

Keiichi Nakagawa ◽

Yukimasa Aoki ◽

Kuni Ohtomo ◽

...

Keyword(s):

Facial Nerve ◽

Gamma Knife ◽

Acoustic Neuroma ◽

Gamma Knife Radiosurgery ◽

Neurofibromatosis Type ◽

Nerve Function ◽

Facial Nerve Function ◽

Content Type ◽

Acoustic Tumor ◽

Fine Print

✓ The authors describe acute deterioration in facial and acoustic neuropathies following radiosurgery for acoustic neuromas. In May 1995, a 26-year-old man, who had no evidence of neurofibromatosis Type 2, was treated with gamma knife radiosurgery (GKS; maximum dose 20 Gy and margin dose 14 Gy) for a right-sided intracanalicular acoustic tumor. Two days after the treatment, he developed headache, vomiting, right-sided facial weakness, tinnitus, and right hearing loss. There was a deterioration of facial nerve function and hearing function from pretreatment values. The facial function worsened from House—Brackmann Grade 1 to 3. Hearing deteriorated from Grade 1 to 5. Magnetic resonance (MR) images, obtained at the same time revealed an obvious decrease in contrast enhancement of the tumor without any change in tumor size or peritumoral edema. Facial nerve function improved gradually and increased to House—Brackmann Grade 2 by 8 months post-GKS. The tumor has been unchanged in size for 5 years, and facial nerve function has also been maintained at Grade 2 with unchanged deafness. This is the first detailed report of immediate facial neuropathy after GKS for acoustic neuroma and MR imaging revealing early possibly toxic changes. Potential explanations for this phenomenon are presented.

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Is Salvage Surgery for Large Vestibular Schwannomas After Failed Gamma-knife Radiosurgery More Challenging?

10.21203/rs.3.rs-560835/v1 ◽

2021 ◽

Author(s):

Lucas Troude ◽

Mohamed Boucekine ◽

Anne Balossier ◽

Guillaume Baucher ◽

Jean-Pierre Lavieille ◽

...

Keyword(s):

Facial Nerve ◽

Gamma Knife ◽

Salvage Surgery ◽

Gamma Knife Radiosurgery ◽

Tumor Control ◽

Nerve Sparing ◽

Nerve Function ◽

Facial Nerve Function ◽

Failure Group

Abstract Objectives: In order to verify whether a previous Gamma-Knife surgery (GKS) treatment could influence the oncological and functional outcome in large vestibular schwannoma (VS) surgery, we have compared group of patients operated on for large VS after failed-GKS to a group of genuine VS that underwent the same functional nerve-sparing resection technique regimen in the same period.Methods: Single center retrospective cohort study of 23 consecutive GKS-failure and 170 genuine VS patients operated on between April 2003 and March 2019. After resection, patients were allocated to a Wait-&-rescan or an upfront GKS policy.Results: At last follow-up examination, the facial nerve function was good (House-Brackmann Grades I or II) in 95% of the GKS-failure and 84% of the genuine VS patients (p=.25). The median volume of tumor residue was .56cc in the GKS-failure group, and .62cc in the genuine VS group (p=.70). Tumor control was achieved in 91% and 83% of cases with a mean follow-up of 74 and 63 months in the GKS-failure and the genuine VS populations, respectively. The 1-, 5- and 7-year progression free survival were 100%, 95% & 85% respectively in the GKS-failure group, and 97%, 80% & 81% in the genuine VS group (p=.27).Conclusion: Despite significant modifications of the microsurgical environment associated to salvage surgery after GKS-failure, a functional nerve-sparing resection is an effective strategy to optimize the results on facial nerve function, with similar long-term tumor control to those observed in the genuine VS population.

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Management of large vestibular schwannoma. Part I. Planned subtotal resection followed by Gamma Knife surgery: radiological and clinical aspects

Journal of Neurosurgery ◽

10.3171/2011.6.jns101958 ◽

2011 ◽

Vol 115 (5) ◽

pp. 875-884 ◽

Cited By ~ 66

Author(s):

Rick van de Langenberg ◽

Patrick E. J. Hanssens ◽

Jacobus J. van Overbeeke ◽

Jeroen B. Verheul ◽

Patty J. Nelemans ◽

...

Keyword(s):

Facial Nerve ◽

Gamma Knife ◽

Treatment Option ◽

Growth Control ◽

Complete Resection ◽

Subtotal Resection ◽

Nerve Function ◽

Facial Nerve Function ◽

Large Vestibular Schwannoma

Object In large vestibular schwannoma (VS), microsurgery is the main treatment option, and complete resection is considered the primary goal. However, previous studies have documented suboptimal facial nerve outcomes in patients who undergo complete resection of large VSs. Subtotal resection is likely to reduce the risk of facial nerve injury but increases the risk of lesion regrowth. Gamma Knife surgery (GKS) can be performed to achieve long-term growth control of residual VS after incomplete resection. In this study the authors report on the results in patients treated using planned subtotal resection followed by GKS with special attention to volumetric growth, control rate, and symptoms. Methods Fifty consecutive patients who underwent the combined treatment strategy of subtotal microsurgical removal and GKS for large VSs between 2002 and 2009 were retrospectively analyzed. Patients with neurofibromatosis Type 2 were excluded. Patient charts were reviewed for clinical symptoms. Audiograms were evaluated to classify hearing pre- and postoperatively. Preoperative and follow-up contrast-enhanced T1-weighted MR images were analyzed using volume-measuring software. Results Surgery was performed via a translabyrinthine (25 patients) or retrosigmoid (25 patients) approach. The median follow-up was 33.8 months. Clinical control was achieved in 92% of the cases and radiological control in 90%. One year after radiosurgery, facial nerve function was good (House-Brackmann Grade I or II) in 94% of the patients. One of the two patients who underwent surgery to preserve hearing maintained serviceable hearing after resection followed by GKS. Conclusions Considering the good tumor growth control and facial nerve function preservation as well as the possibility of preserving serviceable hearing and the low number of complications, subtotal resection followed by GKS can be the treatment option of choice for large VSs.

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