Dose-Volume Effects on Hearing Preservation in Gamma-knife Radiosurgery of Vestibular Schwannomas

2012 ◽  
Vol 84 (3) ◽  
pp. S821-S822
Author(s):  
J. Xue ◽  
J. Grimm ◽  
P. Potrebko ◽  
A. Youssef ◽  
Y. Chen ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Vestibular Schwannomas ◽  
Dose Volume ◽  
Volume Effects

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

2018 ◽  
Vol 128 (1) ◽  
pp. 49-59 ◽  
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.

scholarly journals Gamma knife radiosurgery for vestibular schwannomas: Results of hearing preservation in relation to the cochlear radiation dose

2009 ◽  
Vol 119 (6) ◽  
pp. 1076-1081 ◽  
Author(s):  
Ferdinand C. A. Timmer ◽  
Patrick E. J. Hanssens ◽  
Anniek E. P. van Haren ◽  
Jef J. S. Mulder ◽  
Cor W. R. J. Cremers ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Vestibular Schwannomas

Tumor control and hearing preservation after Gamma Knife radiosurgery for vestibular schwannomas in neurofibromatosis type 2

2010 ◽  
Vol 98 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Manish Singh Sharma ◽  
Rakesh Singh ◽  
Shashank S. Kale ◽  
Deepak Agrawal ◽  
Bhawani Shankar Sharma ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Neurofibromatosis Type ◽  
Hearing Preservation ◽  
Neurofibromatosis Type 2 ◽  
Vestibular Schwannomas ◽  
Tumor Control

scholarly journals Emerging Indications for Fractionated Gamma Knife Radiosurgery

Neurosurgery ◽  
2017 ◽  
Vol 80 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Emory McTyre ◽  
Corbin A. Helis ◽  
Michael Farris ◽  
Lisa Wilkins ◽  
Darrell Sloan ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Vestibular Schwannomas ◽  
Previously Treated ◽  
Immobilization Device ◽  
Gamma Knife Perfexion ◽  
High Degree

Abstract BACKGROUND: Gamma Knife radiosurgery (GKRS) allows for the treatment of intracranial tumors with a high degree of dose conformality and precision. There are, however, certain situations wherein the dose conformality of GKRS is desired, but single-session treatment is contraindicated. In these situations, a traditional pin-based GKRS head frame cannot be used, because it precludes fractionated treatment. OBJECTIVE: To report our experience in treating patients with fractionated GKRS using a relocatable, noninvasive immobilization system. METHODS: Patients were considered candidates for fractionated GKRS if they had 1 or more of the following indications: a benign tumor >10 cc in volume or abutting the optic pathway, a vestibular schwannoma with the intent of hearing preservation, or a tumor previously irradiated with single-fraction GKRS. The immobilization device used for all patients was the Extend system (Leksell Gamma Knife Perfexion, Elekta, Kungstensgatan, Stockholm). RESULTS: We identified 34 patients treated with fractionated GKRS between August 2013 and February 2015. There were a total of 37 tumors treated including 15 meningiomas, 11 pituitary adenomas, 6 brain metastases, 4 vestibular schwannomas, and 1 hemangioma. At last follow-up, all 21 patients treated for perioptic tumors had stable or improved vision and all 4 patients treated for vestibular schwannoma maintained serviceable hearing. No severe adverse events were reported. CONCLUSION: Fractionated GKRS was well tolerated in the treatment of large meningiomas, perioptic tumors, vestibular schwannomas with intent of hearing preservation, and reirradiation of previously treated tumors.

scholarly journals Hearing Preservation after Low-dose Gamma Knife Radiosurgery of Vestibular Schwannomas

2016 ◽  
Vol 56 (4) ◽  
pp. 186-192 ◽  
Author(s):  
Ayako HORIBA ◽  
Motohiro HAYASHI ◽  
Mikhail CHERNOV ◽  
Takakazu KAWAMATA ◽  
Yoshikazu OKADA
Keyword(s):  
Gamma Knife ◽  
Low Dose ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Vestibular Schwannomas

GAMMA KNIFE RADIOSURGERY IN YOUNGER PATIENTS WITH VESTIBULAR SCHWANNOMAS

Neurosurgery ◽  
2009 ◽  
Vol 65 (2) ◽  
pp. 294-301 ◽  
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.

Predictors of Hearing Loss After Gamma Knife Radiosurgery for Vestibular Schwannomas: Age, Cochlear Dose, and Tumor Coverage

Neurosurgery ◽  
2011 ◽  
Vol 69 (3) ◽  
pp. 605-614 ◽  
Author(s):  
Melandee Brown ◽  
Michael Ruckenstein ◽  
Douglas Bigelow ◽  
Kevin Judy ◽  
Vasthi Wilson ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Gamma Knife ◽  
Odds Ratio ◽  
Pure Tone ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Dose Volume Histograms ◽  
Pure Tone Average ◽  
Dose Volume

Abstract BACKGROUND: Deterioration in hearing after Gamma Knife radiosurgery of vestibular schwannomas is a well-documented risk. Recent studies suggest a correlation between cochlear radiation dose and hearing preservation. OBJECTIVE: This study identifies additional variables that predict hearing loss after radiosurgery. METHODS: Retrospective analysis of 53 patients with audiogram follow-up. Median marginal tumor dose was 12.5 Gy. Mean tumor volume was 1.11 cm3. Statistical analysis included multivariate stepwise backward linear regression and multivariate logistic regression. Variables included age, prescription dose, tumor volume, intracanalicular length, and maximum and mean cochlear dose. Dose volume histograms were generated. The percentage of the cochlear volume that received 3.6 Gy or greater, 4.7 Gy or greater, and 5.3 Gy or greater was calculated. Plan conformality indicators were calculated. RESULTS: Forty-two patients had a less than 20-dB change in their pure tone average, with a hearing preservation rate of 79%. Two statistically significant predictors of hearing loss were identified using multivariate analysis: tumor coverage (odds ratio: 1.38 × 1018) and age (odds ratio: 1.1 per year). Multivariate linear regression was used to predict change in pure tone average. Age and percentage of the cochlear volume receiving 5.3 Gy or greater were found to be statistically significant predictor variables. CONCLUSION: Older patients are more vulnerable to detrimental effects of Gamma Knife radiosurgery on hearing. We propose that cochlear dose volume histograms be created and used to reduce the percentage of the cochlear volume exposed to radiation doses greater than 5.3 Gy. This is the first report to suggest that the conformity index tumor coverage may be an important predictor of hearing outcomes.

scholarly journals Gamma Knife Radiosurgery for Large Vestibular Schwannomas: A Canadian Experience

2013 ◽  
Vol 40 (3) ◽  
pp. 342-347 ◽  
Author(s):  
F. A. Zeiler ◽  
M. Bigder ◽  
A. Kaufmann ◽  
P. J. McDonald ◽  
D. Fewer ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Stereotactic Radiosurgery ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Hearing Preservation ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Maximal Diameter

Object:To review our institutional experience with Gamma Knife (GK) stereotactic radiosurgery in treating large vestibular schwannomas (VS) of 3 to 4 cm diameter.Methods:We conducted a retrospective cohort review of all patients treated with GK for VS at our institution between November 2003 and March 2012. Data on age, sex, VS volume, location and maximal diameter, House-Brackmann (HB) facial nerve scores pre and post-GK, Gardner-Robertson (GR) hearing score pre and post-GK, GK treatment parameters, VS response time, complications and clinical outcome was recorded.Results:A total of 28 patients during the defined time period were identified. Three patients were lost to follow-up. Mean follow-up was 34.5 months. Tumor control occurred in 92%, and was maintained in 85.7% at two years. Facial nerve or hearing preservation occurred in all treated compared to pre-GK status, as per HB and GR grading. Transient complications occurred in 80%. Temporary vestibular dysfunction occurred in seven patients (28%). One patient (4%) had the permanent complication of worsening pre-GK hemifacial spasm. Four patients (16%) developed hydrocephalus post-GK.Conclusion:GK stereotactic radiosurgery as a primary treatment modality for large VS can provide acceptable tumor control rates with good facial nerve and hearing preservation, and low complication rates.

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