Potential stereotactic radiosurgery targetsfor metastatic brain tumors.

Features

Evidence-based Guidelines for Stereotactic Radiosurgery: Status and Future Directions

Steven N. Kalkanis, MD, FAANS; Timothy C. Ryken, MD, MS, FAANS, FACS— The most common indication for stereotactic radiosurgery (SRS) has become the treatment of patients with metastatic tumors to the brain. The single biggest controversy has been the relative roles of SRS and whole brain radiation therapy (WBRT), the prior mainstay for metastatic tumor treatment — and, some say, still the “gold standard” against which other methods must be compared.

Evidence-based medicine principles have become increasingly integrated into neurosurgical practice and education. The American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Joint Guidelines Committee (JGC) was created to support these efforts and recently approved a series of guidelines directed at the management of central nervous system metastatic disease. Included within this larger work, recommendations specifically addressing the role of radiosurgery for CNS metastatic disease were enumerated. The JCG methodology dictates that a specific question be addressed, which for SRS was:
Read More

Trends and Opportunities in Radiosurgery

John Buatti, MD—

Radiosurgery continues to rapidly evolve both technologically and in its application to treat a wide variety of clinical conditions. The initially conceived paradigm of intracranial frame-based radiosurgery remains a standard of treatment for patients with intracranial benign and malignant lesions including meningiomas, schwannomas, vascular lesions, trigeminal neuralgia and metastases. Robust frame-based fiducial systems, linked to a customized radiation delivery device, provide proven accuracy in the 0.3 mm range. This still represents the ideal with which other systems are compared. The interdisciplinary interaction of a neurosurgeon, physicist and radiation oncologist remain at the heart of quality treatments, with attention to detailed quality assurance and image-based targeting of identified lesions. Despite the many perfected applications of traditional radiosurgery, there are many others that have beckoned, yet may not be served ideally by this paradigm alone. One clear example is the application of radiosurgery to the broad spectrum of metastatic intracranial disease. In this setting, many radiosurgery patients begin the journey in a known palliative status in which our primary goals are to reduce pain and suffering, improve…
Read More…

Point-Counterpoint: The Role of Stereotactic Radiosurgery Versus Whole Brain Radiotherapy in the Treatment of Central Nervous System Metastatic Disease

Timothy Ryken, MD, MS, FAANS, FACS—

For this issue focusing on stereotactic radiosurgery, Timothy Ryken, MD, MS, FAANS, FACS, presents several cases highlighting central nervous system metastatic disease. John Buatti, MD, then offers the “point” that stereotactic radiosurgery (SRS) is the treatment of choice, while Casandra Foens, MD, offers the “counterpoint” that whole brain radiotherapy (WBRT) is the treatment of choice. Central nervous system metastatic disease remains a significant cause of morbidity (and less often mortality) despite advances in many forms of systemic therapy. The blood-brain barrier hinders the ability of many of the more active and specific agents to target malignant cells that have passed into the central nervous system. The management of these patients has generally involved a discussion of radiation with or without surgical resection.
Read More

Stereotactic Radiosurgery in the Management of Spinal Lesions: An Introduction

Carryn Anderson, MD—

Stereotactic radiosurgery (SRS) is emerging as a therapeutic option for select patients with single-level metastatic disease of the spine. There are a number of machines on the market that can be used to deliver spinal SRS (e.g., TomoTherapy, CyberKnife, Novalis, TrueBeam), but any linear accelerator that can deliver intensity modulated radiation therapy (IMRT) as image-guided RT (IGRT) can be used to deliver treatment. The critical issue for this emerging modality is the experience level of the neurosurgeon and radiation oncologist, the support of physicists who can perform proper quality assurance, and the inclusion of all members of the multidisciplinary oncology team to decide who is an appropriate candidate. Abbreviations EBRT = external beam radiation therapy IGRT = image-guided radiation therapy IMRT = intensity-modulated radiation therapy SBRT = stereotactic body radiation therapy Usually, spinal SRS is used to deliver a high dose of radiation in a single treatment (also called a fraction). However, sometimes the total dose is divided between two to five fractions to spare toxicity to surrounding normal tissues. The dose delivered varies from…
Read More…

Getting Started with Spinal Radiosurgery

Peter C. Gerszten, MD, MPH, FAANS, FACS—

Stereotactic radiosurgery is a rapidly emerging treatment option for spinal neoplasms. The goals of spine radiosurgery parallel those of intracranial radiosurgery, namely to improve local control over conventional fractionated radiotherapy and to have an effectiveness with an acceptable safety profile. It also is an effective salvage therapy in the setting of progression after conventional fractionated treatment. Recent technological developments — including imaging technology for three-dimension localization and pre-treatment planning, intensity-modulated radiotherapy and a higher degree of accuracy in achieving target-dose conformation while sparing normal surrounding tissue — have allowed for the radiosurgical treatment of vertebral body lesions within close proximity to the spinal cord and cauda equine, including intradural and even intramedullary lesions. To date, clinical outcomes have mirrored their counterpart for intracranial radiosurgery. Similar to intracranial radiosurgery, spine radiosurgery has become widely adopted. These are axial and coronal images of the radiosurgery treatment plan of a 35-year-old schoolteacher diagnosed with a symptomatic hemangioblastoma by CT-guided biopsy. The tumor was treated with single-fraction radiosurgery, rather than a traditional open-surgical approach. The patient’s pain resolved within…
Read More…

Neurosurgery Cold Case Post-Mortem Identification

Benjamin J. Figura, PhD; Kathryn Ko, MD, FAANS—

In September of 2003, the body of an unidentified white male was found wrapped in plastic garbage bags in an industrial section of the Bronx. The deceased was in an advanced state of decomposition. The individual was 5’10” and, based on anthropological analysis, estimated to be between 40 and 60 years old. He was notably wearing a light-colored “Brooks Brothers” shirt with a laundry tag labeled “Felix.” The police investigation of this man’s death remains open. The New York City Medical Examiner’s evaluation has left the cause and manner of death as undetermined, but the probability of homicide is low. Of particular interest in this case is evidence of significant prior neurosurgical intervention. As all attempts to identify this individual through forensic methods have failed, the authors are presenting this case with the hope that members of the readership may be able to provide information leading to his identification.

Advertisement