Retreatment of vestibular schwannoma with Gamma Knife radiosurgery: clinical outcome, tumor control, and review of literature (original) (raw)
Related papers
Repeated treatment of vestibular schwannomas after gamma knife radiosurgery
Acta Neurochirurgica, 2009
Purpose When gamma knife radiosurgery (GKS) does not achieve control of the growth of a tumour, the need to repeat treatment is considered. The results and risks of repeat treatment of patients with a vestibular schwannoma were reviewed to assess its efficacy and safety. Methods Between 1992 and 2001, we treated 351 patients with a vestibular schwannoma by GKS, control of the growth of the tumour was not achieved in 32. 26 patients underwntrepeat GKS and five patients had an open microsurgical operation and one stereotactic aspiration of a tumour cyst. Results Twenty-four of 26 patients were followed up after the repeat GKS for a median of 43 months. 15 tumours became smaller, seven remained unchanged and two enlarged. After the second GKS one patient's hearing deteriorated, one developed facial weakness and three facial spasms. One patient required insertion of ventriculoperitoneal drainage. An operation to radically resect the tumour was performed in five patients after the first GKS and for a subtotal removal in one after repeated GKS. Conclusions In the small proportion of patients (9%) in whom initial GKS does not control the growth of a vestibular schwannoma, most can be controlled by further GKS with a very low risk of a complications.
Journal of Neurosurgery, 2016
G amma Knife radiosurgery (GKRS) has become a widely accepted primary treatment modality for small-to medium-size vestibular schwannomas (VSs). Although rates of tumor control after radiosurgery are comparable to those after microsurgery, the advantages of radiosurgery, apart from being a less invasive procedure, include better preservation of cranial nerve (CN) function and of serviceable hearing. 11,20 In the early radiosurgery era, marginal radiation doses as high as 20-70 Gy were applied. 21 This dosage was gradually reduced to 12-13 Gy, after it was shown that lower marginal doses achieved equivalent tumor control but resulted in significantly lower complication rates. 12,18 The first GKRS treatment for VS in the Gamma Knife abbreviatioNs CN = cranial nerve; GKRS = Gamma Knife radiosurgery; VS = vestibular schwannoma.
Journal of neurosurgery, 2014
Since the 1990 s, 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. Of 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 year...
Gamma Knife radiosurgery for larger-volume vestibular schwannomas
Journal of Neurosurgery, 2011
Object Stereotactic radiosurgery (SRS) is an important management option for patients with small- and medium-sized vestibular schwannomas. To assess the potential role of SRS in larger tumors, the authors reviewed their recent experience. Methods Between 1994 and 2008, 65 patients with vestibular schwannomas between 3 and 4 cm in one extracanalicular maximum diameter (median tumor volume 9 ml) underwent Gamma Knife surgery. Seventeen patients (26%) had previously undergone resection. Results The median follow-up duration was 36 months (range 1–146 months). At the first planned imaging follow-up at 6 months, 5 tumors (8%) were slightly expanded, 53 (82%) were stable in size, and 7 (11%) were smaller. Two patients (3%) underwent resection within 6 months due to progressive symptoms. Two years later, with 63 tumors overall after the 2 post-SRS resections, 16 tumors (25%) had a volume reduction of more than 50%, 22 (35%) tumors had a volume reduction of 10–50%, 18 (29%) were stable in v...
Gamma Knife Radiosurgery for Vestibular Schwannomas
2011
The current gamma knife radiosurgery technique involves the use of magnetic resonance imaging for targeting, the application of a low marginal dose (usually between 12 and 13 Gy) and highly conformal treatment planning using multiple small isocenters. This technique achieves an average tumor control rate of 95% and open surgery is needed in fewer than 2 to 3% of patients treated by gamma knife. Facial nerve function preservation is achieved in up to 99% of cases and chance of preserving serviceable hearing is usually between a 70 to 80%. The introduction of ventriculoperitoneal drainage after radiosurgery is required for 1 to 8% of patients. Gamma knife radiosurgery can be treatment of choice for the patients, where the diameter of the tumor is less than 3 cm.
Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases
Journal of Neurosurgery, 2005
Object.The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation.Methods.A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3(range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months.A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a med...
Gamma knife radiosurgery for large vestibular schwannomas: a Canadian experience
The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques, 2013
To review our institutional experience with Gamma Knife (GK) stereotactic radiosurgery in treating large vestibular schwannomas (VS) of 3 to 4 cm diameter. 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 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%). On...
Egyptian Journal of Neurosurgery
Background: Gamma Knife radiosurgery is the principal alternative to microsurgical resection for acoustic neuromas (vestibular schwannomas). However; its increasing use worldwide and evolution of Gamma Knife device precision and safety had led to its acceptance as primary management for small-and medium-sized vestibular schwannomas. We tried to evaluate the tumor volume changes that occur with these tumors following Gamma Knife radiosurgery. Methods: Eighteen patients with stereotactic radiosurgery with Gamma Knife through the year 2016 completed 1-year MRI follow-up at the 3rd, 6th, and 12th month after the Gamma Knife treatment. All the patients had unilateral vestibular schwannomas; the mean dose of radiation to the tumors was 12 Gy (range 10-14 Gy). Post treatment imaging was done with a high-resolution 3 T MRI scanner. Tumor sizes are calculated by using Onis software. Results: Four patterns of volumetric changes were noticed. Most of the tumors increased in size on the third month follow-up MRI (89%); 15 (83%) tumors on the sixth month returned to their initial pre-Gamma Knife radiosurgery (PGKR) sizes. On the last (12th month) follow-up MRI with tumor sizes compared to initial PGKR sizes, 8 (44%) tumors showed no change, 6 (33%) tumors became smaller, and 4 (22%) tumors increase in size. Tumor control rate was 78% for the first year after Gamma Knife radiosurgery. Conclusions: The third month follow-up MR images are practically not informative and might lead to unnecessary intervention; sixth month follow-up MR images are a crucial point and they may predict tumor behavior. Age, gender, and Koos stage whether stage II or III are not affecting tumor control. Gamma Knife radiosurgery is an effective intervention for Koos II and Koos III vestibular schwannomas.
Gamma-knife radiosurgery for vestibular schwannoma
Journal of Korean …, 2001
OBJECT: The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. We document the results of gamma-knife radio-surgery for vestibular schwannoma. METHOD AND OBJECT: Eighty-two patients underwent ...
Journal of Neurological Surgery Part B: Skull Base, 2016
Objectives This study aims to report tumor control rates and cranial nerve function after low dose (11.0 Gy) Gamma knife radiosurgery (GKRS) in patients with vestibular schwannomas. Methods A retrospective chart review was performed on 30 consecutive patients with vestibular schwannomas treated from March 2004 to August 2010 with GKRS at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. The marginal dose for all patients was 11.0 Gy prescribed to the 50% isodose line. Median follow-up time was 42 months. The median treatment volume was 0.53 cm 3. Hearing data were obtained from audiometry reports before and after radiosurgery. Results The actuarial progression free survival (PFS) based on freedom from surgery was 100% at 5 years. PFS based on freedom from persistent growth was 91% at 5 years. One patient experienced tumor progression requiring resection at 87 months. Serviceable hearing, defined as Gardner-Robertson score of I-II, was preserved in 50% of patients. On univariate and multivariate analyses, only higher mean and maximum dose to the cochlea significantly decreased the proportion of patients with serviceable hearing. Conclusion Vestibular schwannomas can be treated with low doses (11.0 Gy) of GKRS with good tumor control and cranial nerve preservation.