Progress in Neurological Surgery

Since its first reported use in 1976 in Sweden, Gamma Knife (GK) radiosurgery has become an accepted treatment option for intracranial meningioma, either upfront, in combination with planned subtotal resection, or as adjuvant/salvage treatment. Initially, GK was used in patients unfit for a major surgical procedure or for high-risk meningiomas adjacent to critical neurovascular structures. However, with the availability of larger and increasingly long-term follow-up studies, the proven durability of GK in the treatment of meningiomas means that it has become a treatment option for younger patients who want to avoid the risks of open surgery...

Gamma Knife radiosurgery (GKRS) of cerebral arteriovenous malformations (AVM) is an accepted treatment option that has been performed for more than 40 years. The goal of AVM GKRS is nidus obliteration to eliminate the risk of intracranial hemorrhage while minimizing the risk of short- and long-term adverse radiation effects (ARE). Nidus obliteration typically occurs between 1 and 5 years after GKRS. The most important factor associated with nidus obliteration is the prescribed radiation dose. The chance of obliteration ranges from 60 to 70% for margin doses of 15-16 Gy to 90% or more for margin doses of 20-25 Gy...

There is a growing body of studies regarding the effects of Gamma Knife radiosurgery on vestibular schwannomas. However, due to their rare presence and variability, our experience with the management of non-vestibular schwannomas is relatively limited. Management strategies include radiological monitoring, microsurgical resection, microsurgery combined with radiosurgery, or upfront radiosurgery. The lack of large series and heterogeneous data makes it difficult to suggest a definitive treatment strategy and management should be tailored for each patient's radiological and clinical characteristics...

Traditional outcome measures after stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVMs) have focused predominantly on angiographic obliteration and general neurologic complications. Several grading scales attempting to predict the outcome for specific patients have previously been proposed and validated, and are outlined here. These have largely been based on both AVM and patient characteristics and attempt to predict obliteration. However, the most practical and clinically oriented goal in the management of AVMs is the prospective avoidance of neurological sequelae manifesting in the form of stroke or death, regardless of AVM obliteration...

A decision to develop a stereotactic radiosurgery center and install the first 201 cobalt-60 Gamma Knife in Pittsburgh was made in 1981 after gathering regional and leadership support. This was part of a 7-year quest that required overcoming barriers to a new technology unfamiliar to US regulatory authorities and insurance companies. The first patient was treated in August 1987. Since that time our center has installed each succeeding Gamma Knife device developed. During an initial 30-year experience we performed more than 14,750 patient procedures...

Stereotactic radiosurgery using the Leksell Gamma Knife has proven to be a valuable alternative to orbital enucleation or fractionated radiation therapy for primary tumors of the orbit, metastatic tumors to the choroid, and primary uveal melanomas. With this approach in a single outpatient setting, the eye is immobilized by a local block after which high-definition MRI or CT is performed to define the target. After rapid dose planning, radiation delivery is completed before the local block dissipates. The tumor response is often dramatic...

Pineal region tumors represent a heterogeneous group of different histologic entities, for which the management can be a significant challenge, due to their critical location and frequent aggressive behavior. Traditional management includes surgical resection, fractionated radiation therapy, and chemotherapy. Stereotactic radiosurgery (SRS) is being increasingly used in the treatment of these tumors. It is used as primary therapy for pineocytomas and papillary tumors of the pineal region, as an adjuvant radiation boost in combination with radiation or chemotherapy for pineoblastomas and germ cell tumors, or in the context of tumor recurrence...

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous connections within the dura, in which meningeal arteries shunt blood directly into the dural sinus or leptomeningeal veins. Among all the treatment options for the treatment of DAVFs, stereotactic radiosurgery (SRS) is a safe and effective modality. SRS provides a minimally invasive therapy for patients who harbor less aggressive DAVFs without cortical vein drainage (CVD), but who suffer from intolerable headache, bruit, or ocular symptoms...

The classification of central neurocytoma (CN) by the WHO was upgraded to grade 2 in 1993 as it was recognized that at least some of these tumors can exhibit more aggressive behavior. Currently, as of 2016, CN is classified as WHO grade 2. Indeed, some atypical variants have been reported and residual postsurgical tumor is believed to have the potential for malignant transformation. Although gross total resection is usually curative for CN (5-year survival rate 99%), it is achieved in nearly 30-50% of cases due to its central location...

The outcome of patients with malignant gliomas has not substantially improved, even with advances in imaging, neurosurgery, molecular subtyping, and radiation, and newer oncologic options. Maximal safe resection when feasible remains the initial treatment of choice for most malignant gliomas. These tumors often recur and require additional therapy to control the tumor growth. Leksell stereotactic radiosurgery (SRS) is offered as salvage therapy in patients with recurrent or residual malignant gliomas. SRS is well tolerated and is associated with a relatively low risk of adverse radiation effects in malignant glial tumor patients who otherwise have relatively few options...

Cavernous malformations (CM) represent a distinct subgroup of brain vascular malformations that are characterized by small sinusoidal vascular channels with hyaline degeneration and old blood pigments. Because of the increasing availability of magnetic resonance imaging (MRI) they are detected much more frequently in the present era. CM may be solitary or found in the context of a familial variant that results in an increasing number of CM developing as the patient ages. Because of the variable risk of subacute bleeding, their management options have been controversial...

Low-grade gliomas represent a heterogeneous group of tumors. The goals of treatment include prolonged survival and reduced morbidity. Treatment strategies vary depending upon tumor histology, anatomic location, age, and the general medical condition of the patient. Safe surgical resection remains the first choice for the treatment of resectable tumors. In cases of unresectable lesions, adjuvant radiotherapy and chemotherapy are considered. Several reports in recent years have documented the safety and effectiveness of stereotactic radiosurgery (SRS) in controlling tumor growth and improving patients' survival for patients with low-grade gliomas...

Glomus tumors of the head and neck typically compress adjacent blood vessels and cranial nerves and result in varied clinical presentations. Moreover, they are seldom encountered, even at large medical centers, and specialists in neurosurgery, otolaryngology, and radiation oncology have yet to reach a generalized consensus regarding the optimal management approach. In an effort to summarize the available data and better elucidate optimal treatment and management strategies for glomus tumors, we conducted a review of the published literature on this topic with emphasis on stereotactic radiosurgery...

Radiosurgery is an effective treatment approach for the management of type 1 trigeminal neuralgia (TN), comparable to other ablative techniques. Also, radiosurgery can effectively treat TN secondary to other causes, including multiple sclerosis, tumor-related TN, as well as other craniofacial neuralgias in select cases with minimal complications. An increasing number of patients favor radiosurgery over other more invasive approaches in order to avoid a general anesthetic, a prolonged hospital stay, and a higher risk of complications...

The JLGK0901 study showed the non-inferiority of stereotactic radiosurgery (SRS) alone as the initial treatment for 5-10 as compared to 2-4 brain metastases (BM) in terms of overall survival and most secondary endpoints [Lancet Oncol 2014;15:387-395]. A trend for patients with 5-10 tumors to undergo SRS alone has since become apparent. The next step is to reappraise whether results of SRS treatment alone for tumor numbers ≥10 differ from those for 2-9 tumors. During the past 2 decades, several retrospective studies have demonstrated the SRS alone treatment strategy to have certain benefits for carefully selected patients with ≥10 BM, i...

Stereotactic radiosurgery (SRS) is an effective treatment for patients with multiple brain metastases. Three decades of increasingly powerful scientific studies have shown that SRS improves outcomes and reduces toxicity when it replaces whole-brain radiation therapy (WBRT). Expert opinion surveys of clinicians have reported that the total intracranial tumor volume rather than the number of brain metastases is related to outcomes. As a result, an increasing number of treating and referring physicians have replaced the reflex use of WBRT with SRS, unless the patient has miliary disease or carcinomatous meningitis...

Here we discuss the low risk of radiation-related complications after Leksell radiosurgery, as well as its diagnosis and management. Using multimodality imaging in the context of clinical suspicion of radiation injury clinicians can now start management with agents designed to reduce the progression of radiation vasculopathy. In more severe cases both medical and surgical management options can be offered.

Chordomas and chondrosarcomas are rare locally aggressive skull base tumors with high progression or recurrence rates. Ultimately, they have high mortality rates unless they respond to multimodality management options that include one or more surgical resections, fractionated radiation therapy, and stereotactic radiosurgery (SRS). SRS has become a standard management option for recurrent or residual chordomas and chondrosarcomas after failed surgical resection and fractionated radiation therapy. This report examines the role of SRS in these skull base tumors...

Tremor is the most prevalent movement disorder in adults. Patients who are refractory to medical management can explore surgical intervention. Deep-brain stimulation (DBS) and radiofrequency thalamotomy (RFT) are surgical procedures for intractable tremor that target the ventralis intermedius (VIM) nucleus to relieve contralateral tremor. For patients who are not candidates for surgical procedures, stereotactic radiosurgery (SRS) is a minimally invasive management option for tremor relief. SRS has been used for the elderly, those considered high surgical risk for other surgical procedures, those who are unresponsive to either DBS or RFT, and those who prefer a less invasive option...

Pituitary adenomas represent a common intracranial pathology, usually resulting in the systemic secretion of hormones and compression of local endocrine and optic structures, causing a wide variety of clinical sequelae. While they are typically treated with upfront endocrine and/or surgical decompressive therapy, in patients with residual, recurrent, or refractory disease, decades of data support management with stereotactic radiosurgery. This modality offers favorable local tumor control, endocrine remission rates, and infrequent toxicity...