Use Of Gamma Knife Radiosurgery Research Articles

A 10-Year Scientometrics Analysis of Brain Tumors Treated with Gamma Knife Radiosurgery: Visualization, Characteristics, and Scientific Trends.

Objective To evaluate the scientometrics characteristics of the scientific production on the treatment of brain tumors with gamma knife radiosurgery in Scopus. Methods The Scopus database (Elsevier) was used to collect all relevant studies for this bibliometric analysis. Data was obtained as a .csv file; it was downloaded from Scopus and was exported by SciVal to Microsoft Excel for a presentation using tables for more detailed analysis. The citations and the number of papers for the most productive institutions, authors, countries, and journals publishing scientific papers were analyzed on the use of gamma knife radiosurgery for brain tumors. Results 458 metadata were obtained from scientific publications, on which inclusion and exclusion criteria were applied, leaving 248 studies. The maximum peak of publications was 2018 with 31 publications, and the minimum peak was 2015 with 18. The most related subtopics were neurology, surgery, and oncology, and most of the retrieved papers had only institutional collaboration. As for more productive journals, Journal of Neurosurgery is first with 23 publications; within the countries with the most scientific publications, we have the United States, Japan, and China. With the United States being the country with the highest number of productions, University of Texas MD Anderson Cancer Center was the main university with the highest scientific production and Sheehan and Trifiletti and American authors dominate the list with the highest number of documents. Conclusion Scientific production regarding gamma knife surgery and brain tumors has been increasing during the last 10 years, with a high incidence during 2018, and the highest number of published articles was in the first quartile. Likewise, the United States is the country with the most publications, authors, and universities on the subject. Greater efforts are still lacking from all countries in the world to reach the quantity and quality of production of the United States.

Lack of delayed neurocognitive side effects of Gamma Knife radiosurgery in acromegaly: the Later-Ac study.

Persistent growth hormone hypersecretion can be observed in roughly 50% of patients operated for somatotroph adenomas, requiring additional treatments. Despite its proven antisecretory efficacy, the use of Gamma Knife radiosurgery (GK) is limited probably due to the lack of data on long-term side effects, including potential cognitive consequences. The LATe Effects of Radiosurgery in Acromegaly study was a cross-sectional exposed/unexposed non-randomized study. The primary objective was to determine the long-term neurocognitive effects of GK focusing on memory, executive functions, and calculation ability. Exposed patients had been treated by GK for acromegaly at least 5 years before inclusion. Unexposed patients (paired for age) had to be cured or controlled at last follow-up without any radiation technique. Patients of both groups were cured or controlled at the last follow-up. Sixty-four patients were evaluated (27 exposed and 37 unexposed). Mean follow-up after GK was 13 ± 6 years (including 24 patients followed for at least 10 years). While up to 23.8% of the patients of the whole cohort presented at least one abnormal cognitive test, we did not observe any significant difference in neurocognitive function between both groups. During the follow-up, 11 patients presented at least one new pituitary deficiency (P = 0.009 for thyroid-stimulating hormone deficiency with a higher rate in exposed patients), two presented a stroke (1 in each group), and one presented a meningioma (12 years after GK). While GK exposes patients to a well-known risk of pituitary deficiency, it does not seem to induce long-term cognitive consequences in patients treated for acromegaly.

Treatment of Radiation-Induced Meningiomas With Non-Invasive Stereotactic Radiosurgery

Radiation-Induced Meningiomas (RIMs) are one of the most common secondary malignancies from prior brain irradiation and are known to be recurrent. While Gamma Knife (GK) radiosurgery is routinely employed for the treatment of sporadic meningiomas, data on its use for RIMs are limited. Here, we assessed whether the use of GK radiosurgery for RIMs can achieve > 80% local control at 1 year.We retrospectively reviewed our institution's GK database from 08/31/99 - 10/08/20. Meningiomas were considered radiation-induced if they met Cahan's criteria: (1) occurred after brain radiation for a previous neoplasm, (2) were within the previous radiation field, and (3) had a distinct histology or radiographic appearance from previously treated neoplasm. Patients with a genetic predisposition for tumor formation were excluded. Endpoints included overall survival (OS), progression free survival (PFS), local failure (within 2cm of GK field), and distant failure. Toxicity was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.A total of 29 patients with 86 RIM lesions were identified from 1999 to 2020 and followed for a median of 59 months. Of these patients, 20 had WHO grade I (n = 4) or presumed grade I (n = 20) RIMs and 5 had WHO grade II RIMs. The median latency time from previous brain irradiation to initial SRS was 26 years. The median dose prescribed to the 50% isodose line was 14 Gy (range 12-20 Gy) with a median lesion volume of 2 cm3. The actuarial 5-yr OS and 5-yr PFS were 95% and 70%, respectively. Patients who were treated for recurrent RIMs after previous surgery had a significantly lower 5-yr OS (88% vs 100%; log-rank, P < 0.0046) and 5-yr PFS (39% vs 81%; log-rank, P < 0.005) than patients who were treated in the upfront setting. On a per-lesion basis, local control at 1-, 3-, and 5-yrs was 82%, 76%, 74%, respectively. Presumed or WHO grade I RIMs had a significantly greater 5-yr local control than WHO grade II RIMs (100% vs 56%, log-rank, P < 0.001). The rate of distant failure at 1-, 3-, and 5-yrs was 3.5%, 18%, and 32%, respectively. At time of progression, 5 patients had distant failures, while 3 patients had local and distant failures. Failures were salvaged through additional GK (n = 8), surgery (n = 2), or chemotherapy (n = 1). The crude incidence of grade 1-3 toxicity from GK was 10% (n = 3). No grade 4 or 5 adverse events were recorded. Only 1 patient developed grade 3 toxicity (cranial nerve neuropathy), which resolved with steroids.This is the largest series of RIM lesions treated with GK radiosurgery. RIMs are associated with a high OS and GK radiosurgery provides satisfactory PFS and local control. Recurrent and WHO grade II lesions are associated with lower PFS and local control after radiosurgery than upfront and WHO grade I lesions. The majority of failures after GK are distant. Treatment using GK radiosurgery has minimal morbidity. It should be considered for patients or tumors that are not candidates for surgical resection.N.Razavian: None. C.A.Helis: None. A.Laxton: None. S.B. Tatter: None. J.Bourland: None. R.T. Mott: None. G.J. Lesser: None. R.Strowd: None. M.D. Chan: None. C.K. Cramer: None.

P14.67 Long-term results of gamma knife radiosurgery for treatment of intracranial glomus jugulare tumors

Abstract BACKGROUND Glomus Jugulare tumors are benign but locally aggressive ones that represent a therapeutic challenge. Previous studies about the use of Gamma Knife Radiosurgery (GRS) in those tumors have documented good results that needed larger number of patients and longer follow up periods to be confirmed. MATERIAL AND METHODS Between August 2001 and December 2017, 70 patients with glomus jugulare tumors were treated at the Gamma Knife Center, Cairo. They were 46 females and 24 males. The mean age was 48 years (16–71 years). Nineteen of these patients were previously operated, 5 were partially embolized, 3 underwent embolization and subsequent surgery and 43 had gamma knife as their primary treatment. Volume-staged gamma knife radiosurgery was used in 10 patients and single-session in 60 patients, with a total of 86 sessions. The mean target volume was 12.7 cm3 (range 0.2 to 34.5 cm3). The mean tumor volume was 15.5 cm3 (range 0.2 to 105 cm3). The mean prescription dose was 14.5 Gy (range 12 to 18 Gy). RESULTS The mean follow up period was 60 months (range 18 to 206 months), and by the time of the data analysis, two of the patients were dead (66 and 24 months after GK treatment). The tumor control was 98.6% (69/70). Thirty-two tumors became smaller and 37 were unchanged. The symptoms improved in 36 patients, were stable in 32 patients, and worsened in 2 patients who developed a transient facial palsy and worsened hearing. Symptomatic improvement began before any reduction in tumor volume could be detected, where the mean time to clinical improvement was 7 months whereas the mean time to tumor shrinkage was 18 months. CONCLUSION This study about the long term follow up of the GKR for the intracranial glomus jugulare tumors confirmed that this is a highly effective and safe treatment. This data shows that the clinical improvement is not correlated with the radiological volume reduction.

Choroidal melanoma treatment in times of coronavirus disease 2019.

Choroidal melanoma treatment in times of coronavirus disease 2019.

Gamma Knife Radiosurgery for Brain Metastases in Non-Small Cell Lung Cancer Patients Treated with Immunotherapy or Targeted Therapy.

Simple SummaryIn non-small cell lung cancer patients with brain metastases, combined Gamma Knife radiosurgery and immunotherapy or targeted therapy showed an increase in overall survival. The combination of Gamma Knife radiosurgery and immunotherapy or targeted therapy did not increase complications related to radiosurgery. Therefore, the combined treatment seems to be a safe and powerful treatment option for non-small cell lung cancer patients with brain metastases.The combination of Gamma Knife radiosurgery (GKRS) and systemic immunotherapy (IT) or targeted therapy (TT) is a novel treatment method for brain metastases (BMs) in non-small cell lung cancer (NSCLC). To elucidate the safety and efficacy of concomitant IT or TT on the outcome after GKRS, 496 NSCLC patients with BMs, who were treated with GKRS were retrospectively reviewed. The median time between the initial lung cancer diagnosis and the diagnosis of brain metastases was one month. The survival after the initial BM diagnosis was significantly longer than the survival predicted by prognostic BM scores. After the first Gamma Knife radiosurgery treatment (GKRS1), the estimated median survival was 9.9 months (95% CI = 8.3–11.4). Patients with concurrent IT or TT presented with a significantly longer survival after GKRS1 than patients without IT or TT (p < 0.001). These significant differences in the survival were also apparent among the four treatment groups and remained significant after adjustment for Karnofsky performance status scale (KPS), recursive partitioning analysis (RPA) class, sex, and multiple BMs. About half of all our patients (46%) developed new distant BMs after GKRS1. Of note, no statistically significant differences in the occurrence of radiation reaction, radiation necrosis, or intralesional hemorrhage in association with IT or TT at or after GKRS1 were observed. In NSCLC-BM patients, the concomitant use of GKRS and IT or TT showed an increase in overall survival without increased complications related to GKRS. Therefore, the combined treatment with GKRS and IT or TT seems to be a safe and powerful treatment option and emphasizes the role of radiosurgery in modern BM treatment.

Gamma knife radiosurgery for uveal melanomas and metastases: a systematic review and meta-analysis.

Gamma knife radiosurgery is regarded as the gold-standard stereotactic radiosurgery modality for the treatment of intracranial tumours, and its use has been expanded for the treatment of intraocular malignancies. The aim of this study was to systematically evaluate the efficacy, outcomes, and complications of gamma knife radiosurgery for uveal melanomas and metastases. We did a systematic review and meta-analysis to aggregate the clinical outcomes of patients with uveal melanomas or intraocular metastases treated primarily with gamma knife radiosurgery. We searched MEDLINE and Embase for studies published between Sept 1, 1960, and Feb 1, 2020, reporting the use of gamma knife radiosurgery as primary treatment for uveal melanoma or uveal metastases. The search was restricted to clinical studies and relevant grey literature published in English. Studies reporting treatment of benign tumours, extraocular tumours, or other forms of stereotactic radiosurgery were excluded to reduce heterogeneity. No restrictions were placed on participant criteria. Local tumour control and tumour regression were extracted as the primary outcomes and analysed via a random-effects meta-analysis of proportions using the DerSimonian and Laird method with a Freeman-Tukey double arcsine transformation. This study is registered with PROSPERO, CRD42019148165. Our search returned 454 studies, of which 109 were assessed for full-text eligibility. 52 studies, reporting on 1010 patients with uveal melanoma and 34 intraocular metastases, were eligible for systematic review. 28 studies were included in the meta-analysis. 840 of 898 patients (0·96, 95% CI 0·94-0·97; I2=16%) from 19 studies had local control, and 378 of 478 patients (0·81, 0·70-0·90; I2=83%) from 16 studies experienced tumour regression. Gamma knife radiosurgery is an efficacious primary method of treating uveal melanomas and intraocular metastases, with reliable tumour control rates. Randomised controlled trials should further evaluate the safety and efficacy of gamma knife radiosurgery in this setting. The Rhodes Trust and the Howard Brain Sciences Foundation.

Evaluation of radiological recurrence patterns following gamma knife radiosurgery for solitary meningioma previously treated via cranial surgery

The use of gamma knife radiosurgery (GKS) for meningiomas after cranial surgery has been extensively evaluated; however, studies on tumor progression, including recurrence out of the margin dose line, are scarce. Hence, we aimed to evaluate the meningioma recurrence after GKS within and out of the margin dose. We included 37 consecutive patients with World Health Organization (WHO) grade 1 meningiomas who were treated with GKS following cranial surgery. Radiologically indicated recurrences were classified into three patterns by their relationship to the margin dose and tumor. The median follow-up was 58.9 months; 2 (5.4%) patients died. Only 2 (5.4%) patients did not keep active daily lives because of tumor progression. Cumulative local control at 5 years was 85.2%. Local recurrence and recurrence out of the margin dose occurred in 5 (13.5%) and 13 (35.1%) patients, respectively. A larger preoperative maximum diameter was a risk factor for local recurrence (hazard ratio [HR]: 2.118; P = 0.033), adjacent progression (HR: 1.633; P = 0.015), and remote progression (HR: 2.016; P = 0.003). Symptomatic adverse radiation effects occurred in 1 patient. Salvage GKS and cranial surgery were performed in 9 (24.3%) and 8 (21.6%) patients, respectively. Progression to WHO grade 2–3 occurred in 5 (13.5%) patients. A larger preoperative maximum diameter was a risk factor for progression of WHO grade (HR: 2.016, P = 0.033). Progression out of the margin dose was associated with a larger preoperative tumor size.

OS8.3 Gamma knife radiosurgery for large meningiomas: 10 years of experience

Abstract BACKGROUND The use of gamma knife radiosurgery for the treatment of intracranial meningiomas has been established as an effective and safe treatment modality. Larger meningiomas are typically managed by surgery followed by radiosurgery. For situations where patients are not amenable to surgery fractionated stereotactic radiotherapy is the traditionally suggested treatment. Treatment of large meningiomas (usually defined as &gt;10 cc) by stereotactic radiosurgery has been investigated in some recent reports, either by single-session, volume-staged or hypofractionation technique. However, there are no long-term results. The purpose of this study is to assess the long-term efficacy and safety of gamma knife radiosurgery for large (15 cc or more) intracranial meningiomas. MATERIAL AND METHODS In this study we included 80 patients with large meningiomas (³ 15 cc) who were followed up for more than 5 years. Non-benign meningiomas were excluded. Also, meningiomatosis and NF2 patients were not included. There were 18 males (22.5%) and 62 females (77.5%). The mean age was 46 years (20–83 years). Twenty-six patients (32.5%) had previous surgery. Tumor were supratentorial in 14 (17.5%) patients and skull base in 66 (82.5%) patients. The mean tumor volume was 22.3 cc (15–57.3 cc). The mean prescription dose was 11 Gy (9–12 Gy). RESULTS The mean follow up period was 8.4 years (5–17 years). The tumor shrank in 43 patients (54%), was stable in 30 patients (37%) and progressed in 7 patients (8%). The tumor control rate was 91%. Adverse radiation effects were observed in 11 patients (14%) but only 5 (6.5%) were symptomatic. These were temporary in all cases. CONCLUSION Gamma knife radiosurgery provides an effective and safe treatment option for large meningiomas. Low margin dose appears to be sufficient for tumor control. Surgery remains the first option in these cases.

Gamma Knife Thalamotomy of Medication Refractory Tremor Disorders

To Investigate the effectiveness and safety of use of Gamma Knife radiosurgery for lesioning the Ventral Intermediate Thalamic Nucleus (VIM) for management of medication refractory tremor disorders. Patients with medication refractory tremor disorders were treated utilizing Gamma Knife radiosurgery. Patients received 130 Gy targeting the VIM nucleus utilizing a single 4 mm collimator shot. Plugs were customized to limit dose to the adjacent internal capsule. Patients were then followed for 2 years with serial standardized Fahn-Tolosa-Marin Tremor scale evaluation and any adverse events were recorded. Results from this testing were tabulated with numerical scores in four separate categories including postural, handwriting, drawing, and functioning. From 2/2013 through 8/2018, 18 patients were treated to 20 lesions. Median age was 69 (range 34-87). Sixteen treatments were directed at the left VIM nucleus to treat a right sided tremor. All of these 16 treatments were directed at the dominant hand. Two of the four patients treated to the non-dominant hand (right VIM nucleus) had also been treated previously to the contralateral side 1 year prior. Fahn-Tolosa-Marin testing was performed at 3-6 month intervals. Median follow up was 18 months (range 0-26) with one patient lost to follow up. 17/19 (89.5%)treatments demonstrated significant improvements on follow up. There were improvements in all assessed scores. Median postural scores improved from 6.0 to 3.0 (p <0.01), handwriting scores from 3.0 to 1.0 ( p<0.01), drawing scores from 9.0 to 3.0 (p<0.01), and functioning scores from 18 to 9.5 (p<0.01). Median time to improvement was 6 months (Range3-24 months). No acute or chronic adverse events were reported in any patient. Gamma Knife Thalamotomy is a safe and effective treatment for tremor disorders. With great care in the delineation of the internal capsule, no adverse events were noted. Treatments can safely be administered in a community setting. Patients who are deemed to be poor candidates for deep brain stimulation including the elderly, patients with pulmonary and cardiac comorbidities, and patients on anticoagulation should be considered for treatment.

EP-1262 Use of Gamma Knife Radiosurgery for Treatment of Trigeminal Neuralgia

EP-1262 Use of Gamma Knife Radiosurgery for Treatment of Trigeminal Neuralgia

Efficacy of gamma knife radiosurgery in brain metastases of primary gynecological tumors.

Gynecological brain metastases (BM) are rare and usually develop as part of widespread disseminated disease. Despite treatment, the majority of these patients do not survive > 1year due to advanced extracranial disease. The use of Gamma Knife Radiosurgery (GKRS) for gynecological BM is not well known. The goal of this study is to evaluate the efficacy of GKRS for gynecological BM. We performed a retrospective study of patients with gynecological BM who underwent GKRS between 2002 and 2015. A total of 41 patients were included. Outcome measures were local tumor control (LC), development of new BM and/or leptomeningeal disease, overall intracranial progression free survival (PFS) and survival. LC was 100%, 92%, 80%, 75% and 67% at 3, 6, 9, 12 and 15 months, respectively. PFS was 90%, 61%, 41%, 23% and 13% at 3, 6, 9, 12 and 15 months, respectively. During follow-up (FU), 18 (44%) patients had intracranial progression. Distant BM occurred in 29% of the patients. Local recurrence and distant recurrence occurred after a mean FU time of 15.5 (2.6-71.9) and 11.4 (2-40) months, respectively. Thirty-one (76%) patients died due to extracranial tumor progression and only 2 (5%) patients died due to progressive intracranial disease. The overall mean survival from time of GKRS was 19months (1-109). The 6-month, 1-year, and 2-year survival rate from the time of GKRS were 71%, 46%, and 22%, respectively. GKRS is a good treatment option for controlling gynecological BM. As most patients die due to extracranial tumor progression, their survival might improve with better systemic treatment options in addition to GKRS.

Local Tumor Control and Clinical Symptoms After Gamma Knife Radiosurgery for Residual and Recurrent Vestibular Schwannomas

The use of Gamma Knife radiosurgery (GKRS) for recurrent or residual vestibular schwannoma (VS) after microsurgery (MS) has been investigated in several retrospective studies. The purpose of this study was to identify potential risk factors for both neurologic deterioration and tumor progression after GKRS for previously operated VSs in a prospective setting. Patients who underwent GKRS for previously operated and histopathologically confirmed VS between 1998 and 2015 were prospectively followed-up. Risk factors for therapy side effects and predictors for tumor control were investigated in uni- and multivariate analyses. A total of 160 individuals with a median age of 55 years were included. Median tumor volume prior to GKRS was 1.40 cm3 (range, 0.06-35.80 cm3). After a median follow-up of 36 months, hearing and facial nerve function were serviceable (modified Gardner-Robertson and House-Brackmann grades I and II) in 7 (5%) and 82 (55%) patients, respectively. Deterioration to a nonserviceable facial nerve function after GKRS was found in 3% (3/89) and tended to increase with rising tumor volume (odds ratio, 1.65 per cm3; 95% confidence interval, 1.00-2.71; P= 0.051). Median tumor volume prior to GKRS was higher in patients with radiologic (P= 0.020) or clinical tumor progression (P<0.001). Critical tumor volume prior to GKRS to predict clinical and radiologic tumor progression was 1.30 cm3 (P< 0.001) and 3.30 cm3 (P= 0.019), respectively. However, in multivariate analyses, none of the analyzed variables were found to independently predict tumor progression. Intended submaximal resection followed by GKRS is a viable treatment for VS. Because tumor remnant size after MS is an important predictor for recurrence after adjuvant GKRS, both brainstem and cerebellar decompression and maximal safely achievable resection should remain major goals of microsurgery.

Salvage gamma knife radiosurgery in the management of dysembryoplastic neuroepithelial tumors: Long-term outcome in a single-institution case series

Background:Dysembryoplastic neuroepithelial tumors (DNT/DNET) are rare epileptogenic tumors. Microsurgery remains the best treatment option, although case reports exist on the use of gamma knife radiosurgery (GKRS) in selected cases. We investigated the long-term outcome of GKRS-treated DNTs at our institution in the context of current diagnostic and treatment options.Case Descriptions:We conducted a retrospective review of three consecutive adult patients (≥18 years) treated with salvage GKRS between 2002 and 2010 at Karolinska University Hospital, Stockholm, Sweden. The case series was supplemented by a review of current literature. A 20-year-old male underwent subtotal resection (STR) in 1997 and 2002 of DNT resulting in temporary control of intractable epilepsy despite antiepileptic drug treatment (AED). Long-term seizure control was obtained after GKRS of two separate residual DNT components along the surgical margin (2005 and 2010). A 27-year-old male undergoing gross total resection of the contrast-enhancing portion of a DNT (1999) resulted in temporary control of intractable epilepsy despite AEDs; lasting clinical control of seizures was achieved in 2002 after GKRS of a small, recurrent DNT component. A 28-year-old male underwent STR of DNT (1994 and 2004) resulting in temporary control of intractable epilepsy. Lasting seizure control was gained after GKRS of a residual tumor (2005).Conclusion:GKRS as performed in our series was effective in terms of tumor and seizure control. No adverse radiation effects were recorded. Prospective studies are warranted to establish the role of GKRS in the treatment of DNTs.

Microinvasive tumor endoresection in combination with ocular stereotactic radiosurgery.

OBJECTIVE The use of Gamma Knife radiosurgery (GKRS) as monotherapy in the treatment of uveal melanoma (UM) allows clinicians to achieve high local tumor control with low recurrence but does not prevent secondary enucleation due to glaucoma in cases of large tumors. The authors analyzed indications for tumor endoresection (ER), the time interval between irradiation and surgery, and the features and results of performing ER for UM after GKRS. METHODS Thirty-seven patients between 28 and 78 years of age (16 male and 11 female patients) with UM underwent GKRS with a dose of 70 to 80 Gy that was applied to the center of the tumor with complete immobilization of the eye during the procedure. Tumor resection with histological investigation was performed in 24 eyes (transscleral resection was performed in 3 eyes, and ER was performed in 21 eyes) at 3 to 97 days after GKRS, mainly during the first 2 or 3 weeks. As a rule, ER (21 eyes) was performed to treat large, centrally localized, or equatorial UMs with exudative macula-on retinal detachment that reduced vision. The average tumor height was 8.9 mm, and the average width was 13.7 mm at the base. ER for UM included phacoemulsification, microinvasive vitrectomy with transretinal tumor resection, laser photocoagulation, and application of a temporary silicone oil tamponade. Seven patients received intraocular injections of inhibitors of angiogenesis for the prevention and treatment of radiation neuroretinopathy. The follow-up period ranged from 8 to 41 months. RESULTS Preservation of the eyes without tumor recurrence was achieved in all 37 patients after GKRS (monotherapy and combined therapy). One patient died of liver metastases at 21 months after GKRS. In the ER group (21 eyes), drug-resistant glaucoma with low visual acuity appeared in 4 eyes (19%) with long-existing total exudative retinal detachment and delayed operations. Severe radiation neuroretinopathy with macular edema occurred in 4 of 21 cases (19%). Intraocular injections of inhibitors of angiogenesis significantly decreased retinal edema. Residual rhegmatogenous retinal detachment was revealed in 1 eye (4.8%). The conservation of the patient's primary vision or its improvement were observed in 11 eyes (52.4%). Useful vision more than 0.1 was achieved in 12 cases (57%), and more than 0.3 was achieved in 8 cases (38%). CONCLUSIONS As a result of this research, ER for UM after GKRS proved to be an effective method of combined eye-conserving treatment for large centrally localized or equatorial tumors at high risk of the emergence and development of toxic tumor syndrome. Perfect eye immobilization, timely ER, and multiple intraocular injections of inhibitors of angiogenesis saved not only the eye in all cases, but also useful vision in many cases. Close cooperation among radiosurgeons, ophthalmologists, and vitreoretinal surgeons is the key to effective treatment.

Worldwide variance in the potential utilization of Gamma Knife radiosurgery.

OBJECTIVE The role of Gamma Knife radiosurgery (GKRS) has expanded worldwide during the past 3 decades. The authors sought to evaluate whether experienced users vary in their estimate of its potential use. METHODS Sixty-six current Gamma Knife users from 24 countries responded to an electronic survey. They estimated the potential role of GKRS for benign and malignant tumors, vascular malformations, and functional disorders. These estimates were compared with published disease epidemiological statistics and the 2014 use reports provided by the Leksell Gamma Knife Society (16,750 cases). RESULTS Respondents reported no significant variation in the estimated use in many conditions for which GKRS is performed: meningiomas, vestibular schwannomas, and arteriovenous malformations. Significant variance in the estimated use of GKRS was noted for pituitary tumors, craniopharyngiomas, and cavernous malformations. For many current indications, the authors found significant variance in GKRS users based in the Americas, Europe, and Asia. Experts estimated that GKRS was used in only 8.5% of the 196,000 eligible cases in 2014. CONCLUSIONS Although there was a general worldwide consensus regarding many major indications for GKRS, significant variability was noted for several more controversial roles. This expert opinion survey also suggested that GKRS is significantly underutilized for many current diagnoses, especially in the Americas. Future studies should be conducted to investigate health care barriers to GKRS for many patients.

Primary Central Nervous System Lymphoma (PCNSL): Analysis of Treatment by Gamma Knife Radiosurgery and Chemotherapy in a Prospective, Observational Study.

Background:Primary central nervous system lymphoma (PCNSL) is a rare cancer accounting for less than 3% of primary brain and central nervous system (CNS) tumors. Tissues involved include the brain parenchyma, leptomeninges, eyes, and spinal cord. High-dose methotrexate (MTX) is the gold standard for newly diagnosed PCNSL. However, Gamma Knife radiosurgery (GKRS) may be efficacious as a co-adjuvant treatment. The purpose of this prospective observational cohort study is to determine the effectiveness of MTX in combination with GKRS in the treatment of PCNSL.Methods:This is a prospective, observational cohort study evaluating the treatment of histologically confirmed PCNSL with MTX as a single agent in a dose of 8 g/m2 (control) and treatment with MTX, plus GKRS. Strict inclusion and exclusion criteria were employed. Primary outcomes were measured by survival rate. Secondary outcomes were assessed by the tumor’s responsiveness to treatment and reduction in size as noted on imaging.Results:Between January 2007 and January 2012, 128 charts were evaluated. Included in this evaluation were 73 chemotherapy (control) and 55 chemotherapy, plus GKRS, patients (variable). The follow-up period was 24 to 49 months (mean: 36.9 months). There were no statistically significant differences in patient demographics or histology diagnosis. Patients were treated with GK doses ranging from 11 Gy to 16 Gy (median: 11 Gy). The median survival rate from initial diagnosis was 26.8 months in the chemotherapy group and 47.6 in the chemotherapy, plus GKRS, group (p-value: 0.0034). All lesions showed a complete response after GKRS when evaluated using magnetic resonance imaging after three to eight weeks (mean range: 6.3 weeks).Conclusions:The use of GKRS is non-invasive, safe, and shows rapid success, improving the prognosis of the patient. This noninvasive treatment modality should be considered as an option for patients with PCNSL. In our study, GKRS as a co-adjuvant therapy to high-dose methotrexate was statistically significant for greater tumor control, enhanced overall survival period, and a lesser number of complications.

Gamma knife radiosurgery in movement disorders: Indications and limitations.

Functional radiosurgery has advanced steadily during the past half century since the development of the gamma knife technique for treating intractable cancer pain. Applications of radiosurgery for intracranial diseases have increased with a focus on understanding radiobiology. Currently, the use of gamma knife radiosurgery to ablate deep brain structures is not widespread because visualization of the functional targets remains difficult despite the increased availability of advanced neuroimaging technology. Moreover, most existing reports have a small sample size or are retrospective. However, increased experience with intraoperative neurophysiological evaluations in radiofrequency thalamotomy and deep brain stimulation supports anatomical and neurophysiological approaches to the ventralis intermedius nucleus. Two recent prospective studies have promoted the clinical application of functional radiosurgery for movement disorders. For example, unilateral gamma knife thalamotomy is a potential alternative to radiofrequency thalamotomy and deep brain stimulation techniques for intractable tremor patients with contraindications for surgery. Despite the promising efficacy of gamma knife thalamotomy, however, these studies did not include sufficient follow-up to confirm long-term effects. Herein, we review the radiobiology literature, various techniques, and the treatment efficacy of gamma knife radiosurgery for patients with movement disorders. Future research should focus on randomized controlled studies and long-term effects. © 2016 International Parkinson and Movement Disorder Society.

RADIOCHIRURGIA STEREOTACTICĂ GAMMA KNIFE (RGK) ÎN TRATAREA MENINGIOAMELOR – STUDIU PE 550 DE PACIENŢI

Introduction. Meningiomas are benign tumors which originate from the cells of the arachnoid granules. Meningiomas represent a special pathologic entity for neurosurgeons due to the fact that they can grow silently for a long time, and can affect important neural structures when they become symptomatic. The total resection of meningiomas is curative. For the meningiomas which are not surgically accessible and for reoccurrence. Gamma Knife radiosurgery (GKS) is a very efficient solution. Materials and methods. The study below presents the experience of the authors regarding the use of GKS for the treatment of meningiomas. The authors focus on a population of 550 patients diagnosed and treated for meningiomas over a period of 10 years at the „Bagdasar-Arseni“ University Hospital in Bucharest. This study compares the impact of GKS when performed alone or in association with open microneurosurgery. The authors assessed patients with tumors ranging between 1 and 42 cm3 in volume. GKS is used successfully to treat meningiomas, both independently and in association with open microsurgery. Results. The major complications of the treatment are represented by lack of response to treatment (7% of patients) and transient cerebral edema (22% of patients). A disturbing phenomenon happens in a few meningiomas of the convexity, with malignant edema (&lt;1%). Conclusion. Given the multiple advantages it has, GKS is right now the tip of the spear regarding the therapeutical methods available for meningiomas. These tumors usually are benign in nature; however, a small percentage are malignant. Often, meningiomas cause no symptoms and require no immediate treatment. But the growth of benign meningiomas can cause serious problems. In some cases, such growth can be fatal. Typically, symptomatic meningiomas are treated with either radiosurgery or conventional surgery. When the tumors met in daily practice are larger than the therapeutical resources of the devices used for GKS, an open microsurgical approach may be attempted followed by stereotactic irradiation of the remnant tumor.

Treatment of brain glioblastoma multiforme with pcDNA3.1-Egr. 1p-p16 combined with gamma knife radiation: An experimental study on nude mice

High post-operative recurrence and poor prognosis are likely to be related to the infiltrative growth of the glioblastoma multiforme (GBM). The primary objective of this study is to investigate the possible synergistic effect of the combined treatment of gamma knife radio-surgery (GKRS) and gene therapy for GBM and secondary objective is to explore the role of GKRS for the temporal and spatial regulation of the gene expression. The study performed on 70 nude mice and randomly divided into seven groups. Subcutaneous injection of human GBM tumor cells (T98G) was carried out to establish the animal models. Various doses of liposome-mediated pcDNA3.1-Egr. 1p-p16 recombinant plasmid were transfected through intra-tumor injection. GKRS was scheduled following the plasmid transfection. Tumor volumes were measured every 4 days after the treatment. Subcutaneous tumor nodule specimens were collected to analyze the cell apoptosis and p16 gene expression using terminal-deoxynucleoitidyl transferase mediated nick end labeling staining and reverse transcription-polymerase chain reaction. Tumor volumes, levels of cell apoptosis and p16 gene expression were compared between groups. Rates of tumor growth were significantly lower in the pcDNA3.1-Egr. 1p-p16 plasmid + GKRS groups than that in the remaining groups 28 days following the GKRS management. The p16mRNA expression was noted in both of the pcDNA3.1-Egr. 1p-p16 plasmid group and the pcDNA3.1-Egr. 1p-p16 plasmid + GKRS with marginal-dose of 20 Gy group. The level of messenger ribonucleic acid expression was higher in the pcDNA3.1-Egr. 1p-p16 plasmid + GKRS with the marginal-dose of 20 Gy group, with a markedly increased apoptotic and necrotic cells, than that in the pcDNA3.1-Egr. 1p-p16 plasmid group. In animal studies, pcDNA3.1-Egr. 1p-p16 in combination with GKRS is a preferable management option for the GBM to the sole use of GKRS or gene therapy. It may be a novel approach for the treatment of human patient with GBM.