Radiocirurgia

BACKGROUND: Gamma Knife radiosurgery (GKRS) has been reported to be an effective modality to treat trigeminal neuralgia. OBJECTIVE: To determine predictive factors for the successful treatment of trigeminal neuralgia with GKRS. METHODS: Between 1999 and 2008, 777 GKRS procedures for patients with trigeminal neuralgia were performed at our institution. Evaluable follow-up data were obtained for 448 patients. Median follow-up time was 20.9 months (range, 3-86 months). The mean maximum prescribed dose was 88 Gy (range, 80-97 Gy). Dosimetric variables recorded included dorsal root entry zone dose, pons maximum dose, dose to the petrous dural ridge, and cisternal nerve length. RESULTS: By 3 months after GKRS, 86% of patients achieved Barrow Neurologic Institute I to III pain scores, with 43% of patients achieving a Barrow Neurologic Institute I pain score. Twenty-six percent of patients reported posttreatment facial numbness; 28% of patients reported a post-GKRS procedure for relapsed pain, and median time to next procedure was 4.4 years. Multivariate analysis revealed that the development of postsurgical numbness (odds ratio [OR], 2.76; P = .006) was the dominant factor predictive of efficacy. Longer cisternal nerve length (OR, 0.85; P = .005), prior radiofrequency ablation (OR, 0.35; P = .028), and diabetes mellitus (OR, 0.38; P = .013) predicted decreased efficacy. The mean dose delivered to the dorsal root entry zone dose in patients who developed facial numbness (57.6 Gy) was more than the mean dose (47.3 Gy) given to patients who did not develop numbness (P = .02). CONCLUSION: The development of post-GKRS facial numbness is a dominant factor that predicts for efficacy of GKRS. History of diabetes mellitus or previous radiofrequency ablation may portend worsened outcome.

http://journals.lww.com/neurosurgery/Fulltext/2012/03000/Predictive_Variables_for_the_Successful_Treatment.7.aspx

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Publication year: 2012
Source: Journal of Clinical Neuroscience, Available online 18 February 2012
Yan Hongmei, Wang Zhe, Wang Jing, Wang Daokui, Cao Peicheng, …
We report a patient who developed delayed cerebrospinal fluid (CSF) rhinorrhea 11 years after gamma knife radiosurgery for a growth hormone (GH)-secreting adenoma. The treatment dose was 18 Gy for the tumor margin (50% isodose). One year later, an MRI of the head revealed that the tumor size had decreased. Eleven years later, the patient developed CSF rhinorrhea from the left nostril. Subsequent MRI examination revealed complete remission of the tumor in the sella turcica and the empty sella. The patient was admitted for direct endoscopic surgical repair of the skull base. We suggest that the cause of the CSF rhinorrhea is secondary empty sella. The other potential causes may be the original invasiveness of the tumor or delayed radiation damage to the mucous membranes of the skull. Long-term follow-up is required to monitor recurrence of CSF rhinorrhea.

http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=IRSSCONTENT&_method=citationSearch&_piikey=S0967586811006291&_version=1&md5=adcb1882b0e19a031b75d97611373696

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

BACKGROUND: Peritumoral edema is a recognized complication following stereotactic radiosurgery (SRS). OBJECTIVE: To evaluate the risk of posttreatment peritumoral edema following SRS for intracranial meningiomas and determine predictive factors. METHODS: Between 2002 and 2008, 173 evaluable patients underwent CyberKnife or Gamma Knife SRS for meningiomas. Eighty-four patients (49%) had prior surgical resections, 13 patients had World Health Organization grade II (atypical) meningiomas, and 117 patients had a neurological deficit before SRS. Sixty-two tumors were in parasagittal, parafalcine, and convexity locations. The median tumor volume was 4.7 mL (range, 0.1-231.8 mL). The median prescribed dose and median prescribed biologically equivalent dose were 15 Gy (range, 9-40 Gy) and 67 Gy (range, 14-116 Gy), respectively. Ninety-seven patients were treated with single-fraction SRS, 74 received 2 to 5 fractions, and 2 received >5 fractions. RESULTS: The median follow-up was 21.0 months. Thirteen patients (8%) developed symptomatic peritumoral edema, with a median onset time of 4.5 months (range, 0.2-9.5 months). The 3-, 6-, 12-, and 24-month actuarial symptomatic edema rates were 2.9%, 4.9%, 7.7%, and 8.5%, respectively. The crude tumor control rate was 94%. On univariate analysis, large tumor volume (P = .01) and single-fraction SRS (P = .04) were predictive for development of posttreatment edema. CONCLUSION: SRS meningioma treatment demonstrated a low incidence of toxicity; however, large tumor volumes and single-fraction SRS treatment had an increased risk for posttreatment edema. Risk factors for edema should be considered in meningiomas treatment.

http://journals.lww.com/neurosurgery/Fulltext/2012/03000/Risk_Factors_for_Posttreatment_Edema_in_Patients.16.aspx

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

BACKGROUND: No prospective study of gamma knife thalamotomy for intractable tremor has previously been reported. OBJECTIVE: To clarify the safety and optimally effective conditions for performing unilateral gamma knife (GK) thalamotomy for tremors of Parkinson disease (PD) and essential tremor (ET), a systematic postirradiation 24-month follow-up study was conducted at 6 institutions. We present the results of this multicenter collaborative trial. METHODS: In total, 72 patients (PD characterized by tremor, n = 59; ET, n = 13) were registered at 6 Japanese institutions. Following our selective thalamotomy procedure, the lateral part of the ventralis intermedius nucleus, 45% of the thalamic length from the anterior tip, was selected as the GK isocenter. A single 130-Gy shot was applied using a 4-mm collimator. Evaluation included neurological examination, magnetic resonance imaging and/or computerized tomography, the unified Parkinson’s disease rating scale (UPDRS), electromyography, medication change, and video observations. RESULTS: Final clinical effects were favorable. Of 53 patients who completed 24 months of follow-up, 43 were evaluated as having excellent or good results (81.1%). UPDRS scores showed tremor improvement (parts II and III). Thalamic lesion size fluctuated but converged to either an almost spherical shape (65.6%), a sphere with streaking (23.4%), or an extended high-signal zone (10.9%). No permanent clinical complications were observed. CONCLUSION: GK thalamotomy is an alternative treatment for intractable tremors of PD as well as for ET. Less invasive intervention may be beneficial to patients.

http://journals.lww.com/neurosurgery/Fulltext/2012/03000/Gamma_Knife_Thalamotomy_for_Parkinson_Disease_and.4.aspx

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Publication year: 2012
Source: World Neurosurgery, Available online 10 February 2012
Shota Tanaka, Bruce E. Pollock, Scott L. Stafford, Michael J. Link
ObjectiveTo assess the outcome of stereotactic radiosurgery (SRS) for patients with benign skull base tumors and trigeminal-related facial pain.MethodsRetrospective review of 31 consecutive patients (25 women, 6 men) with benign skull base tumors and trigeminal pain undergoing SRS between 1991 and 2008. The tumors included 17 posterior fossa meningiomas, 9 cavernous sinus meningiomas and 5 trigeminal schwannomas. The median patient age was 62 years (range, 17-81). In all cases the tumor was the primary target for SRS. The median follow-up after SRS was 50 months (range, 12-184).ResultsThe actuarial tumor control rate after SRS was 95% at both 3 years and 5 years. Eighteen patients (58%) initially achieved complete resolution of trigeminal pain. Higher maximum dose was associated with initial complete pain resolution on a multivariate analysis. However, 7 patients had recurrent pain during follow-up. At last follow-up, only 7 patients (23%) remained pain-free off medications. Further treatment in addition to medical therapy was required for 6 patients (19%).ConclusionAlthough SRS offers excellent radiographic tumor control for benign skull base tumors, durable relief of tumor-related trigeminal pain without medication was noted in only one-fourth of patients at last follow-up.

http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=IRSSCONTENT&_method=citationSearch&_piikey=S1878875012001301&_version=1&md5=7837db38f10e37f0af511adca524ff83

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Abstract Central neurocytoma was originally described as a rare benign neuronal tumor. However, progression and local recurrences after surgery are well recognized. Stereotactic radiosurgery is another option for treatment of CN. In order to evaluate the efficacy of SRS, we performed a quantitative systematic review of the available data on SRS for CN. To identify eligible studies, systematic searches for all CNs treated with SRS were conducted in major scientific publication databases. English studies published prior to May 2011 were reviewed and summarized with reference to the inclusion and exclusion criteria. Tumor local control was analyzed. Heterogeneity and publication bias were assessed, and the summary control rate and 95% confidence interval (CI) were calculated from the raw data. Of 35 eligible studies, five with a total of 64 CNs were included in this quantitative analysis. Four studies reported a mean or median follow-up time of >60 months. The test of heterogeneity was non-significant among the included studies. Publication bias was observed as indicated by an asymmetric funnel plot. There was non-significance in Begg’s test and Egger’s test. The estimated cumulative rate of neuro-imaging tumor control was 91.1% (95% CI = 80.2–96.3%) at a mean follow-up of 59.3 months (range 6–140 months). The P-value was <0.0001 under a random-effect model. Sensitivity analysis showed a similar summary control rates (89.5–93.7%). Based on the summary local control rate of SRS for CN found in this quantitative analysis, we suggest that single session SRS is an effective and safe alternative therapy for recurrent or residual CN. However, the results of our analysis are limited by the predominance of case series studies due to scarcity of published research. Further randomized trials of CN patients via multicenter consortia should be considered for supplementing the weak points in our quantitative analysis.

• Content Type Journal Article
• Category Clinical Study
• Pages 1-7
• DOI 10.1007/s11060-012-0803-x
• Authors
  • Hyung-ki Park, Department of Neurosurgery, Soonchunhyang University, Seoul, South Korea
  • Steven D. Chang, Department of Neurosurgery, Robert C. and Jeannette Powell Professor in the Neurosciences, Stanford University, 300 Pasteur Dr., Room R-225, Stanford, CA 94305, USA

• Journal Journal of Neuro-Oncology
• Online ISSN 1573-7373
• Print ISSN 0167-594X

http://www.springerlink.com/content/e72j6481511u4622/

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM.Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon’s signed rank test.Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision.Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

http://www.redjournal.org/article/PIIS0360301611005268/abstract?rss=yes

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Publication year: 2012
Source: Journal of Clinical Neuroscience, Available online 24 January 2012
P.J. Wilson, K.J. De-loyde, J.R. Williams, R.I. Smee
Non-functioning pituitary adenomas are primarily a surgically managed pathology, but recurrence or regrowth is not uncommon. Previous large series have retrospectively validated the use of the Gamma Knife (GK) as an adjuvant treatment. To our knowledge, we present the largest case series to date with the Linear Accelerator (Linac) for the management of this pathology. In this study we review the clinical course of 118 patients, 51 of whom had stereotactic radiosurgery (SRS) and 67 who had fractionated stereotactic radiotherapy (FSRT); the discriminatory feature being proximity to the optic chiasm. For comparison purposes a population of 53 patients who had conventional radiotherapy (CRT) is included. The local control rates at 5 years for SRS, FRST and CRT were 100%, 93% and 87% respectively. Treatment-related morbidity was low. These data confirm that Linac SRS and FSRT are safe and effective for the treatment of non-functioning pituitary adenomas.

http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=IRSSCONTENT&_method=citationSearch&_piikey=S096758681100498X&_version=1&md5=99786df84e753dc26574ccc971b427cf

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Purpose: Damage to normal tissue is a limiting factor in clinical radiotherapy (RT). We tested the hypothesis that the presence of tumor alters the response of normal tissues to irradiation using a rat in situ brain tumor model.Methods and Materials: Intravital microscopy was used with a rat cranial window to assess the in situ effect of rat C6 glioma on peritumoral tissue with and without RT. The RT regimen included 40 Gy at 8 Gy/day starting Day 5 after tumor implant. Endpoints included blood–brain barrier permeability, clearance index, leukocyte-endothelial interactions and staining for vascular endothelial growth factor (VEGF) glial fibrillary acidic protein, and apoptosis. To characterize the system response to RT, animal survival and tumor surface area and volume were measured. Sham experiments were performed on similar animals implanted with basement membrane matrix absent of tumor cells.Results: The presence of tumor alone increases permeability but has little effect on leukocyte–endothelial interactions and astrogliosis. Radiation alone increases tissue permeability, leukocyte-endothelial interactions, and astrogliosis. The highest levels of permeability and cell adhesion were seen in the model that combined tumor and irradiation; however, the presence of tumor appeared to reduce the volume of rolling leukocytes. Unirradiated tumor and peritumoral tissue had poor clearance. Irradiated tumor and peritumoral tissue had a similar clearance index to irradiated and unirradiated sham-implanted animals. Radiation reduces the presence of VEGF in peritumoral normal tissues but did not affect the amount of apoptosis in the normal tissue. Apoptosis was identified in the tumor tissue with and without radiation.Conclusions: We developed a novel approach to demonstrate that the presence of the tumor in a rat intracranial model alters the response of normal tissues to irradiation.

http://www.redjournal.org/article/PIIS0360301611029142/abstract?rss=yes

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com

Journal of Neurosurgery, Volume 0, Issue 0, Page 1-10, Ahead of Print.
Object Gamma Knife surgery (GKS) has emerged as the treatment of choice for small- to medium-sized cerebral arteriovenous malformations (AVMs) in deep locations. The present study aims to investigate the outcomes of GKS for AVMs in the basal ganglia and thalamus. Methods Between 1989 and 2007, 85 patients with AVMs in the basal ganglia and 97 in the thalamus underwent GKS and were followed up for more than 2 years. The nidus volumes ranged from 0.1 to 29.4 cm3 (mean 3.4 cm3). The mean margin dose at the initial GKS was 21.3 Gy (range 10–28 Gy). Thirty-six patients underwent repeat GKS for residual AVMs at a median 4 years after initial GKS. The mean margin dose at repeat GKS was 21.1 Gy (range 7.5–27 Gy). Results Following a single GKS, total obliteration of the nidus was confirmed on angiograms in 91 patients (50%). In 12 patients (6.6%) a subtotal obliteration was achieved. No flow voids were observed on MR imaging in 14 patients (7.7%). Following single or repeat GKS, total obliteration was angiographically confirmed in 106 patients (58.2%) and subtotal obliteration in 8 patients (4.4%). No flow voids on MR imaging were observed in 18 patients (9.9%). The overall obliteration rates following one or multiple GKSs based on MR imaging or angiography was 68%. A small nidus volume, high margin dose, low number of isocenters, and no history of embolization were significantly associated with an increased rate of obliteration. Twenty-one patients experienced 25 episodes of hemorrhage in 850 risk-years following GKS, yielding an annual hemorrhage rate of 2.9%. Four patients died in this series: 2 due to complications of hemorrhage and 2 due to unrelated diseases. Permanent neurological deficits caused by radiation were noted in 9 patients (4.9%). Conclusions Gamma Knife surgery offers a reasonable chance of obliterating basal ganglia and thalamic AVMs and does so with a low risk of complications. It is an optimal treatment option in patients for whom the anticipated risk of microsurgery is too high.

http://thejns.org/doi/abs/10.3171/2011.12.JNS11542?ai=ru&mi=0&af=R

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Júlio Leonardo B. Pereira
http://lattes.cnpq.br/7687651239699170
http://www.neurocirurgiabr.com