Role of Navigation in the Surgery of Spine Tumours.

Computer-assisted navigation has emerged in neurosurgery as an approach to improve intraoperative orientation and achieve better surgical results with lower complication rates. While the initial use was focused around precise identification of the surgical target, the current applications are much wider and continue to rapidly expand.Here we report our review of the main applications of navigation in spine surgery with a focus on the surgery of spine tumours operated in Sheffield Teaching Hospitals in the past 10 years (2010-2020). In our unit, intraoperative navigation became a helpful and routine adjunct to the modern armamentarium of a spinal surgeon and is currently used not just for accurate placement of the implants but also for precise demarcation of the tumour margins, as well as for identification of important anatomical structures that must be preserved.Conclusion: Intraoperative navigation is a technology that helped us to improve intraoperative orientation to the unexposed anatomy and reduce the risk of iatrogenic complications; achieve better tumour resection; improve the spinal biomechanical construction; provide a safer learning environment for the spinal surgical trainees; minimise radiation exposure of the surgical team and shorten the operating time. In our opinion, it was helpful not only to reduce the risk of complications but also to perform procedures, which without navigation would have been considered inoperable or very high risk.

Feasibility of comparing medical management and surgery (with neurosurgery or stereotactic radiosurgery) with medical management alone in people with symptomatic brain cavernoma - protocol for the Cavernomas: A Randomised Effectiveness (CARE) pilot trial.

INTRODUCTION: The top research priority for cavernoma, identified by a James Lind Alliance Priority setting partnership was 'Does treatment (with neurosurgery or stereotactic radiosurgery) or no treatment improve outcome for people diagnosed with a cavernoma?' This pilot randomised controlled trial (RCT) aims to determine the feasibility of answering this question in a main phase RCT. METHODS AND ANALYSIS: We will perform a pilot phase, parallel group, pragmatic RCT involving approximately 60 children or adults with mental capacity, resident in the UK or Ireland, with an unresected symptomatic brain cavernoma. Participants will be randomised by web-based randomisation 1:1 to treatment with medical management and with surgery (neurosurgery or stereotactic radiosurgery) versus medical management alone, stratified by prerandomisation preference for type of surgery. In addition to 13 feasibility outcomes, the primary clinical outcome is symptomatic intracranial haemorrhage or new persistent/progressive focal neurological deficit measured at 6 monthly intervals. An integrated QuinteT Recruitment Intervention (QRI) evaluates screening logs, audio recordings of recruitment discussions, and interviews with recruiters and patients/parents/carers to identify and address barriers to participation. A Patient Advisory Group has codesigned the study and will oversee its progress. ETHICS AND DISSEMINATION: This study was approved by the Yorkshire and The Humber-Leeds East Research Ethics Committee (21/YH/0046). We will submit manuscripts to peer-reviewed journals, describing the findings of the QRI and the Cavernomas: A Randomised Evaluation (CARE) pilot trial. We will present at national specialty meetings. We will disseminate a plain English summary of the findings of the CARE pilot trial to participants and public audiences with input from, and acknowledgement of, the Patient Advisory Group. TRIAL REGISTRATION NUMBER: ISRCTN41647111.

SRS for Cavernous Malformations: Myths and Realities.

The optimal management of cavernous malformations (CMs) remains controversial. Over the past decade, stereotactic radiosurgery (SRS) has gained wider acceptance in the management of CMs, especially in those with deep location, eloquence, and where surgery is of high risk. Unlike arteriovenous malformations (AVMs), there is no imaging surrogate endpoint to confirm CM obliteration. Clinical response to SRS can only be gauged by a reduction in long-term CM hemorrhage rates. There is concern that the long-term benefits of SRS and the reduced rehemorrhage rate after a latency period of 2 years may only be a reflection of natural history. Of further concern is the development of adverse radiation effects (AREs), which were significant in the early experimental studies. The lessons learnt from that era have led to the progressive development of well-defined, lower marginal dose treatment protocols that have reported less toxicity (5%-7%) and consequently reduced morbidity. Currently, there is at least Class II, Level B evidence for use of SRS in solitary CMs with previous symptomatic hemorrhage in eloquent areas with high surgical risk. Recent prospective cohort studies observing untreated brainstem and thalamic CMs report significantly higher hemorrhage rates and neurological sequelae than the rates reported from contemporary pooled large natural history meta-analyses. Furthermore, this strengthens our recommendation for early proactive SRS in symptomatic deep-seated CMs due to the higher morbidity associated with observation and microsurgery. The key to successful outcomes for any surgical intervention is patient selection. We hope that our precis on contemporary SRS techniques in the management of CMs will assist this process.

Stereotactic Radiosurgery for Benign Cavernous Sinus Meningiomas: A Multicentre Study and Review of the Literature.

Cavernous sinus meningiomas (CSMs) remain a surgical challenge due to the intimate involvement of their contained nerves and blood vessels. Stereotactic radiosurgery (SRS) is a safe and effective minimally invasive alternative for the treatment of small- to medium-sized CSMs. Objective: To assess the medium- to long-term outcomes of SRS for CSMs with respect to tumour growth, prevention of further neurological deterioration and improvement of existing neurological deficits. This multicentric study included data from 15 European institutions. We performed a retrospective observational analysis of 1222 consecutive patients harbouring 1272 benign CSMs. All were treated with Gamma Knife stereotactic radiosurgery (SRS). Clinical and imaging data were retrieved from each centre and entered into a common database. All tumours with imaging follow-up of less than 24 months were excluded. Detailed results from 945 meningiomas (86%) were then analysed. Clinical neurological outcomes were available for 1042 patients (85%). Median imaging follow-up was 67 months (mean 73.4, range 24-233). Median tumour volume was 6.2 cc (+/-7), and the median marginal dose was 14 Gy (+/-3). The post-treatment tumour volume decreased in 549 (58.1%), remained stable in 336 (35.6%) and increased in only 60 lesions (6.3%), yielding a local tumour control rate of 93.7%. Only 27 (2.8%) of the 60 enlarging tumours required further treatment. Five- and ten-year actuarial progression-free survival (PFS) rates were 96.7% and 90.1%, respectively. Tumour control rates were higher for women than men (p = 0.0031), and also for solitary sporadic meningiomas (p = 0.0201). There was no statistically significant difference in outcome for imaging-defined meningiomas when compared with histologically proven WHO Grade-I meningiomas (p = 0.1212). Median clinical follow up was 61 months (mean 64, range 6-233). Permanent morbidity occurred in 5.9% of cases at last follow-up. Stereotactic radiosurgery is a safe and effective method for treating benign CSM in the medium term to long term.

Gamma Knife Stereotactic Radiosurgery for Conjunctival Squamous Cell Carcinoma Invading the Anterior Orbit: A Case Series.

INTRODUCTION: The aim of the study was to report our experience in the use of Gamma Knife Stereotactic Radiosurgery (GKSTRS) for conjunctival squamous cell carcinoma (SCC) invading the orbit, as an alternative to exenteration surgery. PATIENTS AND METHODS: Patients who had GKSTRS for conjunctival SCC invading the orbit but sparing the bone (AJCC eighth ed. T4a) with a minimum of 1-year follow-up were included. Treatment failure was defined as no decrease in tumour size 3 months post-treatment, or further growth during the follow-up period. Patients were followed up 3-monthly for 2 years and 6-monthly afterwards with a minimum of yearly MR Imaging of orbit. RESULTS: Six patients met the inclusion criteria. MR imaging was used to identify the extent of orbital involvement of SCC. Stereotactic radiosurgery utilizing the Leksell Gamma Knife® Perfexion was delivered in a single session in which patients received 18-20 Gy to the 45-50% isodose. The median follow-up was 29 months. Four patients responded to the treatment and had no evidence of recurrence at their most recent follow-up. The treatment failed in 2 patients, in 1 of whom the tumour was larger and extended deeper into the orbit. The other patient developed a recurrence away from the treated area at 9 months, suggesting a multifocal disease. Both patients had poorly differentiated SCC. CONCLUSION: GKSTRS is a potential alternative to orbital exenteration surgery for conjunctival SCC extending into the anterior orbit in a selected group of patients refusing orbital exenteration or has a second blind eye. Nevertheless, the disease is more likely to recur than with exenteration surgery, hence lifelong monitoring and low threshold for surgical intervention or retreatment is prudent.

To suture or not to suture? Does globe immobilisation technique affect clinical outcome in stereotactic radiosurgery for uveal melanoma?

INTRODUCTION: Stereotactic radiosurgery (SRS) is a valuable treatment option for uveal melanoma, offering excellent tumour control rates and eye preservation. Its efficacy relies upon accurate localisation of the tumour, which is challenging in the mobile eye. Various methods of globe immobilisation have been used, including non-invasive devices, such as eye movement tracking and suction cups, but common practice is to use local anaesthetic block with or without transconjunctival suturing of the extraocular muscles. Some studies have suggested that the addition of muscle suturing to local anaesthetic block provides better immobilisation of the globe, when compared to anaesthetic block alone. Controversy exists regarding the clinical relevance of this observation and ocular oncologists differ in their choice of immobilisation technique. METHODS: In order to establish if the addition of muscle suturing to local anaesthetic block improves clinical outcomes, we performed a retrospective review of all cases that underwent SRS for uveal melanoma over a 10-year period (May 2008 to May 2018). Based on surgeon preference, all patients received either local anaesthetic block plus muscle suturing (Group A) or local anaesthetic block alone (Group B) to induce globe akinesia. Outcomes assessed were primary treatment failure, tumour recurrence, secondary enucleation and death rate. RESULTS: In our cohort of 290 eyes; 118 patients were in group A and 172 patients were in group B. There were no cases of primary treatment failure in either group. With a minimum of 24 months follow-up, only 3 patients experienced tumour recurrence (1 in group A and 2 in group B). There was no significant difference in recurrence, enucleation and all-cause death rates between the two groups. CONCLUSION: Our retrospective review suggests that although extraocular muscle suturing may be considered by some units to provide superior globe immobilisation for SRS, it does not alter the clinical outcome.

Long-term safety of gamma knife radiosurgery (SRS) for acromegaly.

PURPOSE: Acromegaly has high morbidity and mortality when growth hormone secretion remains uncontrolled. Stereotactic radiosurgery (SRS) may be used when pituitary surgery is not suitable or unsuccessful, but there are few very long-term safety data available, especially for significant adverse events such as stroke. METHODS: 118 patients with acromegaly were treated with SRS between 1985 and 2015, at the National Centre for Stereotactic Radiosurgery, Sheffield, UK. Data were gathered from case notes, hospital databases, and patient questionnaires. Stroke incidence in comparison to the normal population was quantified using the standardised incidence ratio (SIR), and visual complications assessed. RESULTS: 88% (104/118) had complete morbidity follow up data for analysis. The mean follow-up was 134 months, and median SRS dose was 30 Gy. 81% of tumours had cavernous sinus invasion. There was no excess stroke rate relative to that seen in two age- and sex-matched large population studies (SIR = 1.36, 95% CI 0.27-3.96; SIR = 0.52, 95% CI 0.06-1.89). In 68/104 patients who had MRI-guided SRS with no further radiation treatment (SRS or fractionated radiotherapy) there was no loss of visual acuity and 3% developed ophthalmoplegia. There was a positive correlation between > 1 radiation treatment and both ophthalmoplegia and worsening visual acuity. CONCLUSION: Stroke rate is not increased by SRS for acromegaly. Accurate MRI-based treatment planning and single SRS treatment allow the lowest complication rates. More than one radiation treatment (SRS or fractionated radiotherapy) was associated with increased visual complications.

Gamma Knife Stereotactic Radiosurgery for the treatment of chordomas and chondrosarcomas.

INTRODUCTION: Primary chordomas and chondrosarcomas of the skull base are difficult tumours to treat successfully. Despite advances in surgical techniques, a gross total resection is often impossible to achieve. In addition, some patients may be deemed unsuitable or not wish to undergo extensive surgery for these conditions. This study examines the role of Gamma Knife Stereotactic Radiosurgery (GKRS) in the treatment of these difficult cases. METHODS: All patients harbouring either a chordoma or chondrosarcoma treated at the National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, UK, between 1985 and 2018, were reviewed with regard to their clinical presentations, pre- and post-treatment imaging, GKRS prescriptions and outcomes. RESULTS: In total, 24 patients with a mean tumour volume of 13 cm3 in the chordoma group (n=15) and 12 cm3 in the chondrosarcoma group (n=9) underwent GKRS. The 5- and 10-year overall survival rates for the chordoma group were 67% and 53% respectively, while for the chondrosarcoma group, they were 78% at both time points. The tumour control rates at 5 and 10 years in the chordoma group were 67% and 49% and for the chondrosarcoma group 78% at both time points. Patients with tumour volumes of less than 7 cm3 before GKRS treatment demonstrated a statistically significant longer overall survival rate (p=0.03). CONCLUSIONS: GKRS offers a comparable option to proton beam therapy for the treatment of these tumours. Early intervention for tumour volumes of less than 7 cm3 gives the best long-term survival rates.

Intracranial Masson Lesion Following Stereotactic Radiosurgery for Treatment of Intracranial Arteriovenous Malformations.

OBJECTIVES: Masson tumor or intravascular papillary endothelial cell proliferation was first described in 1923. Only a few cases of intracranial Masson tumor have been reported following stereotactic radiosurgery (SRS). We report a series of 6 cases, age range 28-56 years, with intracranial Masson tumor following SRS for treatment of an intracranial arteriovenous malformation (AVM). METHODS: We performed a retrospective case note review, reviewed the imaging, SRS records, and neuropathology specimens following surgical excision. RESULTS: In our series all patients received Leksell SRS with the periphery of the AVM receiving doses ranging from 22-25 Gy. The time lapse from SRS to a clear enhancing mass appearing on imaging ranged from 5-10 years. Four patients underwent craniotomy and excision of the enhancing lesion for persistent edema and an enlarging cyst resulting in a resolution of symptoms. CONCLUSIONS: SRS is an effective treatment for obliteration of intracranial AVMs.

Skull base aneurysmal bone cyst presenting with hydrocephalus: progressive residuum obliterated by Gamma Knife stereotactic radiosurgery in a pediatric patient.

Aneurysmal bone cysts (ABCs) are an uncommon entity predominantly encountered in the pediatric population. The skull is rarely involved, but these cysts have been reported to arise in the skull base. Traditional treatment has been with surgery alone; however, there is a gathering body of literature that reports alternative treatments that can achieve long-term disease-free survival. However, these therapies are predominantly directed at peripheral skeletal lesions. To the authors' knowledge, this report is the first to describe long-term follow-up of the efficacy of Gamma Knife stereotactic radiosurgery for treatment of ABC residuum in the skull base that resulted in long-term patient stability and likely ABC obliteration.

A Retrospective Analysis of the Role of Single-Session Gamma Knife Stereotactic Radiosurgery in Sporadic Vestibular Schwannomas with Tumor Volumes Greater Than 10 cm3: Is It Worth Stretching the Boundaries?

OBJECTIVE: To evaluate the role of single-session Gamma Knife stereotactic radiosurgery (GK-SRS) in the treatment of vestibular schwannomas (VSs) with volumes of greater 10 cm3. METHODS: A retrospective analysis was performed of 103 patients treated with single-session GK-SRS between 1993 and 2011 with a mean follow-up of 6.2 years ± 4.4 SD. Treatment, clinical and outcome details were recorded and assessed. RESULTS: Eighty-one (78.6%) patients achieved radiological control with slow progression in a further 5 (4.9%) patients, who did not require further treatment. Linear measurements did not correlate well with volume, which can predict outcome following treatment more precisely. 2.9% of patients developed a new facial paresis, 5.8% trigeminal numbness and 2.9% facial pain. In all, 26 (25.2%) patients who were tested preserved some level of hearing following treatment. CONCLUSIONS: The overall radiological control rate in this study was 78.6%, while tumor volumes less than 20 cm3 can be safely treated with single-stage GK-SRS with an expected control rate of 83.2% without unacceptable morbidity rates. GK-SRS can be utilized as a first-line treatment option in patients with large-volume VSs especially in whom surgery is unattractive.

Radiosurgery as primary management for acromegaly.

OBJECTIVE: Transsphenoidal surgery (TSS) remains the recommended primary treatment for acromegaly. Long-term outcome data are not available for patients treated with gamma knife radiosurgery (STRS) as a primary treatment. DESIGN: Retrospective cohort study. DATA COLLECTION: notes review, laboratory results, general physician notes, patient questionnaire and death certification. PATIENTS: Twenty acromegaly patients underwent primary STRS at the National Centre for Radiosurgery, Sheffield, UK, between 1985 and 2015. MEASUREMENTS: Biochemical control (GH/IGF1), hypopituitarism, morbidity and mortality were all recorded. RESULTS: At 20 years of follow-up, control was seen in all on acromegaly-specific medication (n = 12) and 75% of those off medication (3/4). Time for 50% to achieve control on medication was 3 years, and 7.4 years off medication. Median marginal radiation dose was 27.5 Gy, and median follow-up was 166.5 months. 53% of patients developed new hypopituitarism at a median follow-up of 146 months, and the development of first onset of hypopituitarism occurred as late as 20 years after treatment. With MRI planning, no other complications were noted. Three patients underwent subsequent TSS due to poor biochemical control. During follow-up, 7 patients died at a median age of 65 years. There were no STRS-related deaths. CONCLUSION: This is the longest follow-up of patients who have undergone primary STRS for acromegaly. It shows low morbidity, but significant latency to biochemical control and new-onset hypopituitarism. This mandates very long-term follow-up for these patients. STRS has shown good long-term efficacy providing initial control can be afforded by optimal medical management. While TSS remains best practice, STRS offers an alternative for those in whom surgery is not an option.

Repeat Radiosurgery Treatment After Cavernous Malformation Radiosurgery.

OBJECTIVE: Of cavernous malformations (CMs) treated with radiosurgery (RS), 5% bleed after 2-year initial latency period. This rate is similar to failure rate of RS for other pathologies, which often require repeat RS for favorable outcome. The aim of this pilot study was to define failure of CM RS and to assess safety of second RS. METHODS: Retrospective analysis was performed of 7 of 345 CMs retreated with RS; 6 CMs were deep-seated, and 1 was superficial. Median time between the 2 treatments was 8 years (range, 3-16 years), and median follow-up time after second RS was 3 years (range, 1-9 years). RESULTS: Following the 2-year latency period after RS, 6% of deep-seated and 5% of hemispheric CMs, and 6% of deep-seated and 2% of hemispheric lesions caused transient neurologic deficits without hemorrhage. A second treatment was indicated for rebleed in 5 cases and for recurrent transient neurologic deficits in 2 cases. Prescribed dose was 15 Gy (range, 12-20 Gy) at first treatment and 12 Gy (range, 12-18 Gy) at second treatment. Target volumes were 692 mm3 (range, 54-2400 mm3) and 935 mm3 (range, 150-1550 mm3) at first and second treatments, respectively, and treatment volumes were 811 mm3 (range, 79-2500 mm3) and 962 mm3 (range, 194-1750 mm3), respectively. Differences in treatment parameters were not significant. Reason for failure was inaccurate target definition in only 2 cases. There were no bleeds, morbidity, or mortality after second RS. CONCLUSIONS: Second RS applied to previously treated CMs is safe and may be effective. Further investigations are needed to verify these findings and assess long-term benefit of second RS.

Contemporary radiosurgery of cerebral cavernous malformations: Part 1. Treatment outcome for critically located hemorrhagic lesions.

OBJECTIVELong-term benefits of radiosurgery (RS) applying modern protocols to treat cavernous malformations (CMs) remain unclear as critics may consider the decrease in the rebleed rate generally observed 2 years after RS as a reflection of the lesion's natural history. The authors adopted an early intention-to-treat attitude since rehemorrhage from deep-seated CMs ultimately leads to stepwise neurological deterioration. The safety of this early policy was previously demonstrated. Here, the authors revisit their current practice in a larger population with a longer follow-up time to assess the long-term effects of RS in the context of current knowledge on the natural history of CMs.METHODSThe authors conducted a retrospective analysis of 210 patients with 210 hemorrhagic CMs located in the brainstem, thalamus, or basal ganglia and treated with Gamma Knife RS between 1995 and 2014. Two hundred six patients had available follow-up, which was a median of 5.5 years (range 1-20 years). The median age was 37 years (0.5-77 years) at presentation and 43 (2-78) at treatment. One hundred twenty-seven CMs had bled once and 83 had had multiple hemorrhages prior to treatment.RESULTSThe lifetime annual bleed rate of CMs having a single hemorrhage prior to treatment was 2.4% per lesion. The hemorrhage rate stabilized at 1.1% after a temporary increase of 4.3% within the first 2 years after RS. The annual pretreatment hemorrhage rate was 2.8% for the lesions having multiple bleeds prior to RS with a pretreatment rebleed rate of 20.7% and with a modest gradual decrease within the first 5 years and remaining stable at 11.55% thereafter. The rebleed rate fell to 7.9% for the first 2 years after RS and declined further to 1.3% thereafter, which was significantly lower than the long-term pretreatment rebleed risk. The rate of hemorrhage-free survival remained 86.4% and 75.1% (1 patient each) at 20 years after RS in the single- and multiple-bleed groups, respectively.Pretreatment hemorrhages resulted in permanent deficits in 48.8% of the cases with a single bleed and in 77.1% of the cases with multiple bleeds. Both the rate and severity of deficits were significantly lower in the first group. Only mild and a low rate of permanent neurological deficits were caused either by posttreatment hemorrhages (7.4%) or by radiation (7.2%). The rate of persistent morbidity in the single-bleed group remained significantly lower at the end of the study than pretreatment morbidity in the multiple-bleed group (OR 2.9, 95% CI 1.6-5.3). Lesion-specific mortality was < 1%.CONCLUSIONSThe hemorrhage rate of CMs after RS remained low after the first 2 years during the longer follow-up period. The benefit of early treatment appears to be confirmed by the study results as repeated hemorrhages carry the risk of significantly higher cumulative morbidity than the morbidity associated with RS.

Contemporary radiosurgery of cerebral cavernous malformations: Part 2. Treatment outcome for hemispheric lesions.

OBJECTIVEThe role of radiosurgery (RS) in treating superficial cavernous malformations (CMs) is insufficiently studied in part because of the disappointing results of early experimental attempts as compared to the mostly safe and effective microsurgery. Nonetheless, because of lesion- or treatment-specific factors, a therapeutic alternative may be required. In this study, the authors aimed to assess the safety of RS in treating superficial CMs and to analyze its long-term effect on hemorrhage rates and epilepsy control.METHODSThe authors conducted a retrospective analysis of 96 patients with 109 CMs located in the cerebral or cerebellar hemispheres and treated with RS between 1995 and 2014. A median of 15 Gy (range 10-25 Gy) was given to the 50% prescription isodose level, lesion volume was 604 mm3 (4-8300 mm3), and the prescription isodose volume was 638.5 mm3 (4-9500 mm3). Outcomes were compared to those of 206 deep-seated lesions reported on in another study. Ninety-five patients had available follow-up, which was a median of 7 years (1-21 years). Median patient age was 42 years (0.5-77) at presentation and 45 (3-80) at treatment. Seventy-one CMs presented with symptomatic hemorrhage, and 52 caused seizures.RESULTSIn the nonhemorrhagic group (37 lesions), one bleed occurred during the follow-up period, for an annual bleed rate of 0.4% per lesion. The lifetime annual bleed rate of CMs having a single hemorrhage prior to treatment was 2.5%. The rebleed rate in the single-bleed group decreased from 1.8% within the first 2 years after RS to 0.7% thereafter. The pretreatment rebleed rate for lesions having multiple bleeds prior to RS was 14.15%, which fell to 3.85% for the first 2 years after RS and declined to 1.3% thereafter. Multivariate analysis showed younger age, deep lesion location, and multiple pretreatment hemorrhages as significant predictors of posttreatment hemorrhage.Pretreatment hemorrhages led to permanent deficits in 41.4% of the cases with a single bleed and in 46.1% of cases with multiple bleeds. Only mild (modified Rankin Scale score 1) and a low rate of permanent neurological deficits were caused either by posttreatment hemorrhages (4.3%) or by radiation (2%).The rate of improvement in epilepsy was 84.9% after RS in patients with at least one seizure prior to treatment, not depending on the presence of hemorrhage or the time interval between presentation and treatment. Favorable outcome occurred in 81% of patients whose seizures were not controlled with antiepileptic medication prior to RS.CONCLUSIONSRadiosurgery for superficial CMs is safe and appears to be effective, offering a real treatment alternative to surgery for selected patients. Given their relatively benign natural history, superficial CMs require further study to verify the long-term benefit of RS over the lesions' natural history.

European consensus conference on unruptured brain AVMs treatment (Supported by EANS, ESMINT, EGKS, and SINCH).

In December of 2016, a Consensus Conference on unruptured AVM treatment, involving 24 members of the three European societies dealing with the treatment of cerebral AVMs (EANS, ESMINT, and EGKS) was held in Milan, Italy. The panel made the following statements and general recommendations: (1) Brain arteriovenous malformation (AVM) is a complex disease associated with potentially severe natural history; (2) The results of a randomized trial (ARUBA) cannot be applied equally for all unruptured brain arteriovenous malformation (uBAVM) and for all treatment modalities; (3) Considering the multiple treatment modalities available, patients with uBAVMs should be evaluated by an interdisciplinary neurovascular team consisting of neurosurgeons, neurointerventionalists, radiosurgeons, and neurologists experienced in the diagnosis and treatment of brain AVM; (4) Balancing the risk of hemorrhage and the associated restrictions of everyday activities related to untreated unruptured AVMs against the risk of treatment, there are sufficient indications to treat unruptured AVMs grade 1 and 2 (Spetzler-Martin); (5) There may be indications for treating patients with higher grades, based on a case-to-case consensus decision of the experienced team; (6) If treatment is indicated, the primary strategy should be defined by the multidisciplinary team prior to the beginning of the treatment and should aim at complete eradication of the uBAVM; (7) After having considered the pros and cons of a randomized trial vs. a registry, the panel proposed a prospective European Multidisciplinary Registry.

Staged-Volume Radiosurgery of Large Arteriovenous Malformations Improves Outcome by Reducing the Rate of Adverse Radiation Effects.

Background: The treatment of large arteriovenous malformations (AVMs) remains challenging. Recently, staged-volume radiosurgery (SVRS) has become an option. Objective: To compare the outcome of SVRS on large AVMs with our historical, single-stage radiosurgery (SSRS) series. Methods: We have been prospectively collecting data of patients treated by SVRS since 2007. There were 84 patients who had a median age of 37 years (range, 9-62 years) who were treated until July 2013. The outcomes of 76 of those who had follow-ups available were analyzed and compared with the outcomes of 122 patients treated with the best SSRS technique. Results: There were 21.5% of AVMs that were deep seated, and 44% presented with hemorrhage resulting in 45% fixed neurological deficit. There were 14% of patients who had undergone embolization before radiosurgery. The median nidus treatment volume was 19.7 cm3 (6.65-68.7) and 17.5 Gy (13-22.5) prescription isodose was given. Of the 44 lesions having radiological follow-up at 4 years, 61.4% were completely obliterated. Previous embolization (50% with and 63% without) and higher Spetzler-Martin grades appeared to be the negative factors in successful obliteration, but treatment volume was not. Within 3 years after radiosurgery, the annual bleed rates of unruptured and previously ruptured AVMs were 3.2% and 5.6%, respectively. Three bleeds were fatal and 2 resulted in significant modified Rankin scale 3 morbidity. These rates differ little from SSRS. Temporary adverse radiation effects (AREs) did not change significantly, but permanent AREs dropped from 15% to 6.5% (P = .03) compared with SSRS. Conclusion: Obliteration and hemorrhage rates of large AVMs treated by SVRS are similar to historical SSRS. However, SVRS offers a lower rate of AREs.

Gamma Knife radiosurgery for glomus jugulare tumors: a single-center series of 75 cases.

OBJECTIVE Glomus jugulare tumors are rare indolent tumors that frequently involve the lower cranial nerves (CNs). Complete resection can be difficult and associated with lower CN injury. Gamma Knife radiosurgery (GKRS) has established its role as a noninvasive alternative treatment option for these often formidable lesions. The authors aimed to review their experience at the National Centre for Stereotactic Radiosurgery, Sheffield, United Kingdom, specifically the long-term tumor control rate and complications of GKRS for these lesions. METHODS Clinical and radiological data were retrospectively reviewed for patients treated between March 1994 and December 2010. Data were available for 75 patients harboring 76 tumors. The tumors in 3 patients were treated in 2 stages. Familial and/or hereditary history was noted in 12 patients, 2 of whom had catecholamine-secreting and/or active tumors. Gamma Knife radiosurgery was the primary treatment modality in 47 patients (63%). The median age at the time of treatment was 55 years. The median tumor volume was 7 cm3, and the median radiosurgical dose to the tumor margin was 18 Gy (range 12-25 Gy). The median duration of radiological follow-up was 51.5 months (range 12-230 months), and the median clinical follow-up was 38.5 months (range 6-223 months). RESULTS The overall tumor control rate was 93.4% with low CN morbidity. Improvement of preexisting deficits was noted in 15 patients (20%). A stationary clinical course and no progression of symptoms were noted in 48 patients (64%). Twelve patients (16%) had new symptoms or progression of their preexisting symptoms. The Kaplan-Meier actuarial tumor control rate was 92.2% at 5 years and 86.3% at 10 years. CONCLUSIONS Gamma Knife radiosurgery offers a risk-versus-benefit treatment option with very low CN morbidity and stable long-term results.

Gamma knife surgery for pediatric arteriovenous malformations: a 25-year retrospective study.

OBJECT: The authors present their 25-year experience in treating pediatric arteriovenous malformations (AVMs) to allow comparisons with other historic studies and data in adults. METHODS: Data were collected from a prospectively maintained departmental database selected for age and supplemented by case note review and telephone interviews as appropriate. RESULTS: Three hundred sixty-three patients, ages 1-16 years (mean ± SD, 12 ± 3.2 years), underwent 410 treatments; 4 had planned 2-stage treatments and 43 were retreated subsequent to an initial partial response. Fifty-eight percent received general anesthesia for the procedure. Sixteen percent had previously undergone embolization. The most common presenting symptoms were as follows: hemorrhage (80.2%), epilepsy (8.3%; overall seizure prevalence 19.9%), and migrainous headaches (6.3%). Only 0.28% of the AVMs were incidental findings. The mean lesion volume was 3.75 ± 5.3 cm3 (range 0.01-32.8 cm3), with a median Spetzler-Martin grade of III (range I-V). The mean peripheral (therapeutic) dose was 22.7 ± 2.3 Gy (range 15-25 Gy), corresponding to a mean maximum dose of 43.6 ± 6 Gy (range 25-51.4 Gy). The obliteration rate was 71.3% in patients who received one treatment and 62.5% for retreated patients, with a mean obliteration time of 32.4 and 79.6 months, respectively. The overall obliteration rate was 82.7%. No follow-up data are as yet available for the 4 patients who underwent the staged treatments. Only 4 patients received peripheral doses below 20 Gy, and the AVM was obliterated in 3 of these patients. The other patients received 20, 22.5, or 25 Gy and had obliteration rates of 82.6%, 77.7%, and 86.3%, respectively. The bleeding rate postradiosurgery was 2.2%, and the cumulative complication rate was 3.6%, with radionecrosis being the most common complication (1.1%). CONCLUSIONS: Surprisingly, there was no correlation (p = 0.43) between outcome and radiosurgical dose when that dose was between 20 and 25 Gy, thus suggesting that the lower of these 2 doses may be effective. Radiosurgery for pediatric AVM is safe and effective.