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

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii184-ii185
Author(s):  
Umberto Tosi ◽  
Sergio Guadix ◽  
Anjile An ◽  
Drew Wright ◽  
Andrew Brandmaier ◽  
...  

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.

2021 ◽  
Author(s):  
Umberto Tosi ◽  
Sergio Guadix ◽  
Anjile An ◽  
Drew Wright ◽  
Paul J Christos ◽  
...  

Abstract Background Vestibular schwannomas (VS) are tumors of the cerebellopontine angle with significant morbidity, causing hearing loss, tinnitus, and trigeminal and facial nerve compromise. An effective alternative to microsurgical resection is stereotactic radiosurgery, which can be delivered in either single fraction (SRS) or hypofractionated (3-5 treatments) regimens (hSRT). It remains unclear which fractionation regimen provides superior outcomes. Methods Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Reviews were searched for studies either comparing hSRT with SRS or focusing on hSRT alone in treating VS. Primary endpoints included tumor control, serviceable hearing, tinnitus, and cranial nerve V and VII 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 94% (95% CI: 88%, 99%) of 1571 patients. There was no difference between pre- and post-treatment odds ratios (OR) of tinnitus, facial, or trigeminal impairment. Serviceable hearing was diminished following hSRT (OR = 0·60, 95% CI: 0·44, 0·83). Comparison with SRS showed no difference with respect to tumor control, serviceable hearing, trigeminal or facial nerve impairment. Conclusions hSRT achieved excellent tumor control and, with the exception of serviceable hearing, did not result in worse post-treatment cranial nerve symptomatology. Analysis of comparative studies between hSRT and SRS did not reveal any significant difference in either tumor control or treatment morbidities.


2021 ◽  
Author(s):  
Umberto Tosi ◽  
Miguel E Tusa Lavieri ◽  
Anjile An ◽  
Omri Maayan ◽  
Sergio W Guadix ◽  
...  

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.


Author(s):  
Anne Balossier ◽  
Jean Régis ◽  
Nicolas Reyns ◽  
Pierre-Hugues Roche ◽  
Roy Thomas Daniel ◽  
...  

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.


Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Kevin Ding ◽  
Edwin Ng ◽  
Prasanth Romiyo ◽  
Dillon Dejam ◽  
Courtney Duong ◽  
...  

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.


2020 ◽  
Vol 188 ◽  
pp. 105571 ◽  
Author(s):  
Kevin Ding ◽  
Edwin Ng ◽  
Prasanth Romiyo ◽  
Dillon Dejam ◽  
Methma Udawatta ◽  
...  

Neurosurgery ◽  
2003 ◽  
Vol 53 (3) ◽  
pp. 577-588 ◽  
Author(s):  
Damien C. Weber ◽  
Annie W. Chan ◽  
Marc R. Bussiere ◽  
Griffith R. Harsh ◽  
Marek Ancukiewicz ◽  
...  

Abstract OBJECTIVE We sought to determine the tumor control rate and cranial nerve function outcomes in patients with vestibular schwannomas who were treated with proton beam stereotactic radiosurgery. METHODS Between November 1992 and August 2000, 88 patients with vestibular schwannomas were treated at the Harvard Cyclotron Laboratory with proton beam stereotactic radiosurgery in which two to four convergent fixed beams of 160-MeV protons were applied. The median transverse diameter was 16 mm (range, 2.5–35 mm), and the median tumor volume was 1.4 cm3 (range, 0.1–15.9 cm3). Surgical resection had been performed previously in 15 patients (17%). Facial nerve function (House-Brackmann Grade 1) and trigeminal nerve function were normal in 79 patients (89.8%). Eight patients (9%) had good or excellent hearing (Gardner-Robertson [GR] Grade 1), and 13 patients (15%) had serviceable hearing (GR Grade 2). A median dose of 12 cobalt Gray equivalents (range, 10–18 cobalt Gray equivalents) was prescribed to the 70 to 108% isodose lines (median, 70%). The median follow-up period was 38.7 months (range, 12–102.6 mo). RESULTS The actuarial 2- and 5-year tumor control rates were 95.3% (95% confidence interval [CI], 90.9–99.9%) and 93.6% (95% CI, 88.3–99.3%). Salvage radiosurgery was performed in one patient 32.5 months after treatment, and a craniotomy was required 19.1 months after treatment in another patient with hemorrhage in the vicinity of a stable tumor. Three patients (3.4%) underwent shunting for hydrocephalus, and a subsequent partial resection was performed in one of these patients. The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2–98.3%). Of the 21 patients (24%) with functional hearing (GR Grade 1 or 2), 7 (33.3%) retained serviceable hearing ability (GR Grade 2). Actuarial 5-year normal facial and trigeminal nerve function preservation rates were 91.1% (95% CI, 85–97.6%) and 89.4% (95% CI, 82–96.7%). Univariate analysis revealed that prescribed dose (P = 0.005), maximum dose (P = 0.006), and the inhomogeneity coefficient (P = 0.03) were associated with a significant risk of long-term facial neuropathy. No other cranial nerve deficits or cancer relapses were observed. CONCLUSION Proton beam stereotactic radiosurgery has been shown to be an effective means of tumor control. A high radiological response rate was observed. Excellent facial and trigeminal nerve function preservation rates were achieved. A reduced prescribed dose is associated with a significant decrease in facial neuropathy.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii131-ii132
Author(s):  
Umberto Tosi ◽  
Omri Maayan ◽  
Anjile An ◽  
Miguel Lavieri ◽  
Sergio Guadix ◽  
...  

Abstract BACKGROUND One of the hallmarks of neurofibromatosis type 2 (NF2) is the presence of bilateral vestibular schwannomas (VSs) that result in progressive hearing loss and compression of nearby brainstem structures causing cranial nerve palsies. Treatment of these tumors remains challenging, as both surgical removal and expectant management can result in symptom progression. Stereotactic radiosurgery (SRS) has recently been investigated for the management of NF2-associated VSs; however, the role, promises, and pitfalls of this treatment modality remain unclear. METHODS Ovid MEDLINE, EMBASE, Web of Science, and Cochrane Reviews were searched for studies assessing SRS outcome in NF2-associated VSs only. Primary endpoints included tumor control, serviceable hearing, presence of tinnitus, and cranial nerve V and VII symptoms. RESULTS A total of 16 studies (589 patients harboring 750 tumors) was included in this analysis. Clinical tumor control was achieved in 88% of cases (95% CI: 80%-95%); salvage surgery was needed in 8% (95% CI: 4%-13%) of cases. Treatment resulted in a worsening of pre-treatment serviceable hearing (OR of 0.26, p &lt; 0.01), in an increase of facial nerve impairment (OR of 1.62, p &lt; 0.01), and showed a trend for increase trigeminal nerve impairment as well (OR of 1.42, p = 0.07). The incidence of vestibular symptoms and hydrocephalus requiring shunting could not be assessed since these measures were not reported consistently. CONCLUSIONS The treatment of NF2-associated VS continues to pose a challenge, as current SRS regimens result in impaired hearing and worse cranial nerve comorbidities, despite achieving high tumor control. It remains unclear if these findings have to be intended as treatment complications or, rather, continuous disease progression despite tumor control.


2021 ◽  
Author(s):  
Amey Rajan Savardekar ◽  
Danielle L Terrell ◽  
Saudamini Jayant Lele ◽  
Ryan Robert Diaz ◽  
Praneeth Reddy Keesari ◽  
...  

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%).


Author(s):  
F. A. Zeiler ◽  
M. Bigder ◽  
A. Kaufmann ◽  
P. J. McDonald ◽  
D. Fewer ◽  
...  

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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