Ablative brain surgery: an overview Franzini, Andrea; Moosa, Shayan; Servello, Domenico ...
International journal of hyperthermia,
10/1/2019, 2019-10-00, 2019-10-01, 20191001, Volume:
36, Issue:
2
Journal Article
Peer reviewed
Open access
Background: Ablative therapies have been used for the treatment of neurological disorders for many years. They have been used both for creating therapeutic lesions within dysfunctional brain circuits ...and to destroy intracranial tumors and space-occupying masses. Despite the introduction of new effective drugs and neuromodulative techniques, which became more popular and subsequently caused brain ablation techniques to fall out favor, recent technological advances have led to the resurgence of lesioning with an improved safety profile. Currently, the four main ablative techniques that are used for ablative brain surgery are radiofrequency thermoablation, stereotactic radiosurgery, laser interstitial thermal therapy and magnetic resonance-guided focused ultrasound thermal ablation.
Object: To review the physical principles underlying brain ablative therapies and to describe their use for neurological disorders.
Methods: The literature regarding the neurosurgical applications of brain ablative therapies has been reviewed.
Results: Ablative treatments have been used for several neurological disorders, including movement disorders, psychiatric disorders, chronic pain, drug-resistant epilepsy and brain tumors.
Conclusions: There are several ongoing efforts to use novel ablative therapies directed towards the brain. The recent development of techniques that allow for precise targeting, accurate delivery of thermal doses and real-time visualization of induced tissue damage during the procedure have resulted in novel techniques for cerebral ablation such as magnetic resonance-guided focused ultrasound or laser interstitial thermal therapy. However, older techniques such as radiofrequency thermal ablation or stereotactic radiosurgery still have a pivotal role in the management of a variety of neurological disorders.
OBJECTIVE Several recent studies have improved our understanding of the outcomes of volume-staged (VS) and dose-staged (DS) stereotactic radiosurgery (SRS) for the treatment of large (volume > 10 cm
...) brain arteriovenous malformations (AVMs). In light of these recent additions to the literature, the aim of this systematic review is to provide an updated comparison of VS-SRS and DS-SRS for large AVMs. METHODS A systematic review of the literature was performed using PubMed to identify cohorts of 5 or more patients with large AVMs who had been treated with VS-SRS or DS-SRS. Baseline data and post-SRS outcomes were extracted for analysis. RESULTS A total of 11 VS-SRS and 10 DS-SRS studies comprising 299 and 219 eligible patients, respectively, were included for analysis. The mean obliteration rates for VS-SRS and DS-SRS were 41.2% (95% CI 31.4%-50.9%) and 32.3% (95% CI 15.9%-48.8%), respectively. Based on pooled individual patient data, the outcomes for patients treated with VS-SRS were obliteration in 40.3% (110/273), symptomatic radiation-induced changes (RICs) in 13.7% (44/322), post-SRS hemorrhage in 19.5% (50/256), and death in 7.4% (24/323); whereas the outcomes for patients treated with DS-SRS were obliteration in 32.7% (72/220), symptomatic RICs in 12.2% (31/254), post-SRS hemorrhage in 10.6% (30/282), and death in 4.6% (13/281). CONCLUSIONS Volume-staged SRS appears to afford higher obliteration rates than those achieved with DS-SRS, although with a less favorable complication profile. Therefore, VS-SRS or DS-SRS may be a reasonable treatment approach for large AVMs, either as stand-alone therapy or as a component of a multimodality management strategy.
The goal of this study was to evaluate the obliteration rate of intracranial dural arteriovenous fistulas (DAVFs) in patients treated with stereotactic radiosurgery (SRS), and to compare obliteration ...rates between cavernous sinus (CS) and noncavernous sinus (NCS) DAVFs, and between DAVFs with and without cortical venous drainage (CVD).
A systematic literature review was performed using PubMed. The CS DAVFs and the NCS DAVFs were categorized using the Barrow and Borden classification systems, respectively. The DAVFs were also categorized by location and by the presence of CVD. Statistical analyses of pooled data were conducted to assess complete obliteration rates in CS and NCS DAVFs, and in DAVFs with and without CVD.
Nineteen studies were included, comprising 729 patients harboring 743 DAVFs treated with SRS. The mean obliteration rate was 63% (95% CI 52.4%-73.6%). Complete obliteration for CS and NCS DAVFs was achieved in 73% and 58% of patients, respectively. No significant difference in obliteration rates between CS and NCS DAVFs was found (OR 1.72, 95% CI 0.66-4.46; p=0.27). Complete obliteration in DAVFs with and without CVD was observed in 56% and 75% of patients, respectively. A significantly higher obliteration rate was observed in DAVFs without CVD compared with DAVFs with CVD (OR 2.37, 95% CI 1.07-5.28; p=0.03).
Treatment with SRS offers favorable rates of DAVF obliteration with low complication rates. Patients harboring DAVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using SRS.
The aim in this paper was to compare the outcomes of dose-staged and volume-staged stereotactic radio-surgery (SRS) in the treatment of large (> 10 cm(3)) arteriovenous malformations (AVMs).
A ...systematic literature review was performed using PubMed. Studies written in the English language with at least 5 patients harboring large (> 10 cm(3)) AVMs treated with dose- or volume-staged SRS that reported post-treatment outcomes data were selected for review. Demographic information, radiosurgical treatment parameters, and post-SRS outcomes and complications were analyzed for each of these studies.
The mean complete obliteration rates for the dose- and volume-staged groups were 22.8% and 47.5%, respectively. Complete obliteration was demonstrated in 30 of 161 (18.6%) and 59 of 120 (49.2%) patients in the dose- and volume-staged groups, respectively. The mean rates of symptomatic radiation-induced changes were 13.5% and 13.6% in dose- and volume-staged groups, respectively. The mean rates of cumulative post-SRS latency period hemorrhage were 12.3% and 17.8% in the dose- and volume-staged groups, respectively. The mean rates of post-SRS mortality were 3.2% and 4.6% in dose- and volume-staged groups, respectively.
Volume-staged SRS affords higher obliteration rates and similar complication rates compared with dose-staged SRS. Thus, volume-staged SRS may be a superior approach for large AVMs that are not amenable to single-session SRS. Staged radiosurgery should be considered as an efficacious component of multimodality AVM management.
Glioblastoma multiforme (GBM) is the most common and lethal form of brain cancer and these tumors are highly resistant to chemo- and radiotherapy. Radioresistance is thought to result from a paucity ...of molecular oxygen in hypoxic tumor regions, resulting in reduced DNA damage and enhanced cellular defense mechanisms. Efforts to counteract tumor hypoxia during radiotherapy are limited by an attendant increase in the sensitivity of healthy brain tissue to radiation. However, the presence of heightened levels of molecular oxygen during radiotherapy, while conventionally deemed critical for adjuvant oxygen therapy to sensitize hypoxic tumor tissue, might not actually be necessary. We evaluated the concept that pre-treating tumor tissue by transiently elevating tissue oxygenation prior to radiation exposure could increase the efficacy of radiotherapy, even when radiotherapy is administered after the return of tumor tissue oxygen to hypoxic baseline levels. Using nude mice bearing intracranial U87-luciferase xenografts, and in vitro models of tumor hypoxia, the efficacy of oxygen pretreatment for producing radiosensitization was tested. Oxygen-induced radiosensitization of tumor tissue was observed in GBM xenografts, as seen by suppression of tumor growth and increased survival. Additionally, rodent and human glioma cells, and human glioma stem cells, exhibited prolonged enhanced vulnerability to radiation after oxygen pretreatment in vitro, even when radiation was delivered under hypoxic conditions. Over-expression of HIF-1α reduced this radiosensitization, indicating that this effect is mediated, in part, via a change in HIF-1-dependent mechanisms. Importantly, an identical duration of transient hyperoxic exposure does not sensitize normal human astrocytes to radiation in vitro. Taken together, these results indicate that briefly pre-treating tumors with elevated levels of oxygen prior to radiotherapy may represent a means for selectively targeting radiation-resistant hypoxic cancer cells, and could serve as a safe and effective adjuvant to radiation therapy for patients with GBM.
A recent randomized controlled trial investigating unilateral MRI-guided focused ultrasound (FUS) for essential tremor demonstrated efficacy. The long-term durability of this thalamotomy, however, is ...unknown. Furthermore, the feasibility of stimulating a previously lesioned target such as the thalamic nucleus ventralis intermedius (Vim) is poorly understood. We report a case of tremor recurrence, following an initially successful FUS thalamotomy, in which Vim-DBS was subsequently utilized to regain tremor control.
An 81-year-old right-handed female with medically refractory essential tremor (a Clinical Rating Scale for Tremor CRST value of 73) underwent left-sided FUS thalamotomy with initial abolition of right-upper extremity tremor. By the 6-month follow-up, there was complete recurrence of tremor (a CRST value of 76). The patient subsequently underwent left-sided Vim-DBS.
Vim-DBS provided clinical improvement with a CRST value of 42 at the 3-month follow-up; the patient continues to do clinically well at the 6-month follow-up. This result mirrors previous reported cases of stimulation following radiofrequency and gamma-knife lesioning. Our literature review highlights several reasons for the waning of clinical benefit seen with lesional procedures.
This case demonstrates that thalamic DBS can salvage a failed FUS thalamotomy and also the feasibility of stimulating a previously lesioned target.
Functional neurosurgery resource features state-of-the-art approaches from renowned experts! For patients with inadequately treated epilepsy, tremor, dystonia, spasticity, depression, ...obsessive-compulsive disorder, Parkinson's and Alzheimer's disease, functional neurosurgery offers hope. Functional Neurosurgery: The Essentials is a reader-friendly introduction to this fascinating and rapidly evolving field. The text is edited by internationally prominent functional neurosurgeons Jeffrey A. Brown, Julie G. Pilitsis, and Michael Schulder. It features contributions from authors with expertise spanning the disciplines of neurosurgery, neurology, rehabilitation and physical medicine, neurophysiology, bioengineering, psychiatry and ophthalmology. Opening with a brief history of stereotaxy/functional neurosurgery and brain stereotactic frames, 41 concise and coherent chapters explore cutting-edge approaches to a broad range of functionally treatable conditions. The chapters yield a solid foundation of understanding of the field, with insightful commentary, pearls, and nuances from the editors. The starting question in the neuroprosthetics chapter, "Can a computer infer human intention or perception?" brings to life the exciting, inquisitive, and pioneering spirit of this subspecialty. The robust reference list provides a guide to deeper study that should continue throughout training and practice. Highlights * Imaging: MRI and CT for stereotactic neurosurgery, fMRI and resting state MRI * Movement disorders: A comparative analysis of the risks and benefits of deep brain stimulation versus lesioning * Epilepsy: Temporal lobectomy and extra-temporal surgery; invasive monitoring, neuromodulation, laser interstitial thermal therapy, and vagus nerve stimulation * Dystonia: Etiology to diagnosis, medical and surgical options * Future innovations: Exoskeletons, intention controlled, and visual neuroprosthetics The text is a fundamental resource for neurosurgical residents during their functional neurosurgery rotations and for general neurosurgeons and functional subspecialists on procedures they may not routinely perform in clinical practice.
An indispensable, single-volume resource on state-of-the-art epilepsy procedures from renowned international experts! Epilepsy is a common neurological disorder affecting an estimated 1% of the ...population, about 20 to 30% of which experience seizures inadequately controlled by medical therapy alone. Advances in anatomic and functional imaging modalities, stereotaxy, and the integration of neuronavigation during surgery have led to cutting-edge treatment options for patients with medically refractory epilepsy. Operative Techniques in Epilepsy Surgery, Second Edition by Gordon Baltuch, Arthur Cukiert, and an impressive international group of contributors has been updated and expanded, reflecting the newest treatments for pediatric and adult epilepsy. Seven sections with 30 chapters encompass surgical planning, invasive EEG studies, cortical resection, intraoperative mapping, disconnection, neuromodulation, and further topics. Twelve cortical resection chapters cover surgical approaches such as amygdalohippocampectomy; hippocampal transection; frontal lobe, central region, and posterior quadrant resections; and microsurgery versus endoscopy for hypothalamic hamartomas. Disconnection procedures discussed in section five include corpus callosotomy, hemispherectomy, and endoscopic-assisted approaches. Well-established procedures such as vagus nerve and deep brain stimulation are covered in the neuromodulation section, while the last section discusses radiosurgery for medically intractable cases. Key Highlights * Chapters new to this edition include endoscopic callosotomy, laser-induced thermal therapy (LITT), and focused ultrasound * High-quality illustrations, superb operative and cadaver photographs, radiologic images, and tables enhance understanding of impacted anatomy and specific techniques * The addition of videos provides insightful step-by-step procedural guidance This is an essential reference for fellows and residents interested in epilepsy and functional neurosurgery, and an ideal overview for neurosurgeons, neurologists, and neuroradiologists in early career stages who wish to pursue this subspecialty.
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