William Friedman

• University of Florida

Objective: The safety of single-treatment stereotactic radiosurgery (SRS) for vestibular schwannoma (VS) with radiographic evidence of brainstem compression but without motor deficit is controversial. Data on linear accelerator (linac)-based SRS in this setting are scarce. We address this with an outcomes report from an unselected series of patien...

Background: Data are scarce on the efficacy of a second radiosurgery (SRS) treatment of vestibular schwannoma that has progressed following initial treatment with SRS. We sought to report the outcome of our repeat SRS series with long-term imaging follow-up. Materials and methods: We retrospectively analyzed 6 patients who met the following crit...

Linear accelerator radiosurgery uses a LINAC as the source of highly energetic photons. These photons, called X-rays, are produced electronically rather than through the spontaneous decay of a radioactive isotope (gamma rays), like cobalt in the Gamma Knife. The X-ray beam is collimated and aimed at the stereotactic target point. A variety of treat...

Radiosurgery has become a popular alternative to microsurgery for small arteriovenous malformations (AVM). Numerous reports document high obliteration rates (around 80%) and low radiation induced complication rates (around 2%). Gamma knife, linear accelerator, and particle beam systems are all viable options. The major drawback of radiosurgery is t...

Objectives: To determine the long-term outcome after stereotactic radiosurgery (SRS) for temporal bone paragangliomas. Materials and methods: We retrospectively reviewed the medical records of 11 patients with temporal bone paragangliomas (10 patients with a glomus jugulare tumor and 1 patient with a glomus tympanicum tumor) treated between Janu...

Identifying factors that contribute to the aggressiveness of glioblastoma (GBM) is crucial for treating this deadly brain tumor. We demonstrate here that CD70, a member of the TNF family, is overexpressed by tumor cells in a subset of patients with low grade glioma and GBM. The elevated gene and protein expression is associated with increased tumor...

Radiosurgery is truly minimally invasive treatment, delivering therapeutic energy to an accurately defined target without an incision. It has been used to treat a wide variety of pathologic conditions including benign and malignant brain tumors, vascular lesions such as arteriovenous malformations, and pain syndromes such as trigeminal neuralgia. A...

INTRODUCTION: High quality tumor samples and DNA, coupled with annotated clinical data are the building blocks of basic, translational, and clinical research but are often difficult to obtain in a high-quality and standardized format and are expensive to maintain. In 2006, the legislature of the State of Florida appropriated funding for the Florida...

Background: Despite the conformity of stereotactic radiosurgery (SRS) treatment, there are concerns about the risk of malignancy. Objective: We compared the number of cancer cases observed after treatment in a group of SRS patients to the number of cancer cases that would be expected in an age- and gender-matched group. Methods: We collected d...

Objective Starting in October 2012, the Center for Medicare and Medicaid Services (CMS) began to reduce payments to hospitals that have disproportionately high rates of readmission within 30 days following discharge. Factors associated with readmission rates for neurosurgical patients remain largely uninvestigated. Our Objective is to identify defi...

During the last two decades, there has been a shift in the United States healthcare system towards improving the quality of healthcare provided by enhancing patient safety and reducing medical errors. Unfortunately, surgical complications, patient harm events, and malpractice claims remain common in the field of neurosurgery. Many of these events a...

: The reported prevalence rates of arteriovenous malformations (AVMs) in the general population range from 0.001% to 0.50%. The following case describes the initial presentation of hemorrhage from an intracranial AVM in an 18-year-old college football player. It also discusses treatment of the AVM with stereotactic radiosurgery and successful retur...

Objectives:: To determine the influence of secretory status on long-term outcome after fractionated radiotherapy (RT) for gross residual pituitary adenoma. Materials and methods:: This is a retrospective study of 116 consecutively treated patients who met the following inclusion criteria: tissue diagnosis of pituitary adenoma, visible tumor at t...

OBJECT: Estimating survival time in cancer patients is crucial for clinicians, patients, families, and payers. To provide appropriate and cost-effective care, various data sources are used to provide rational, reliable, and reproducible estimates. The accuracy of such estimates is unknown. METHODS: The authors prospectively estimated survival in 15...

Stereotactic radiosurgery for intracranial arteriovenous malformations (AVMs) has been performed since the 1970s. When an AVM is treated with radiosurgery, radiation injury to the vascular endothelium induces the proliferation of smooth muscle cells and the elaboration of extracellular collagen, which leads to progressive stenosis and obliteration...

BACKGROUND Surgical education is moving rapidly to the use of simulation for technical training of residents and maintenance or upgrading of surgical skills in clinical practice. To optimize the learning exercise, it is essential that both visual and haptic cues are presented to best present a real-world experience. Many systems attempt to achieve...

Stereotactic radiosurgery (SRS) is a procedure that delivers a single large radiation dose to a well-defined target. Here, we describe a frameless SRS technique suitable for intracranial targets in canines. Medical records of dogs diagnosed with a primary intracranial tumour by imaging or histopathology that underwent SRS were retrospectively revie...

Objective We previously performed a nationwide survey of American neurosurgical residents before the initiation of the 2011 Accreditation Council for Graduate Medical Education regulations, in which more than 70% indicated the proposed changes would negatively impact residency training. We sought to resurvey the resident population as to the actual...

INTRODUCTION: Cervical radiculopathy due to cervical spondylosis is commonly treated by either posterior cervical foraminotomy (PCF) or anterior cervical discectomy and fusion with plating (ACDFP). The present study analyzes the cost effectiveness of ACDFP vs PCF for patients with single-level cervical radiculopathy. METHODS: Forty-five patients wh...

Stereotactic radiosurgery is ideal for treating small cerebral arteriovenous malformations that are surgically inaccessible. However, given the inherent delay of AVM obliteration and the potential for radiosurgical failure, detailed evaluation of the neurovascular architecture is necessary to monitor persistence of residual flow. Modern imaging sys...

The nervous system is organized in such a way that a careful history and physical will almost always allow the clinician to localize the site of disease. This requires a basic knowledge of the neurological exam and the anatomy that underlies that exam. In this chapter we will review the examination of mental status, cranial nerves, motor, reflex, a...

To explain the concepts that radiation oncologists should understand to manage patients with optic nerve sheath meningioma (ONSM). To accomplish this goal we first describe our institution's experience with the treatment of ONSM with radiation therapy and then use this data set as a framework for explaining the role of radiation therapy in the trea...

We introduce a taxonomy for mixed simulation focusing on mixed simulators with physical exteriors augmented with virtual underlays for practicing medical procedures such as central venous access (CVA). We used CT and MRI imaging and 3D printing to develop anatomically authentic mixed simulators, i.e., exact physical and/or virtual replicas of their...

Listening to an injured brain is not easy. It takes knowledge, dedication, and understanding of the critically ill patient and their family. It takes an appreciation of the logistics of care in these difficult times of imbalance between more and sicker patients and fewer medical specialists. The impact of the right personnel, whose interest and tr...

Object: Ventricular infection after ventriculostomy placement carries a high mortality rate. Responding to ventriculostomy infection rates, a multidisciplinary performance improvement team was formed, a comprehensive protocol for ventriculostomy placement was developed, and the efficacy was evaluated. Methods: A best-practice protocol was develo...

Most of us have appreciated Mixed Reality (MR) in the form of the virtual "yellow first down line" when watching football on TV. However, MR technology was previously confined to a few pioneering groups and was not readily available. Simply defined, MR integrates the virtual and physical worlds to generate new environments where real and virtual ob...

Previous studies suggest that nonurgent pages comprise a substantial portion of the pages received by residents while on duty. We evaluated the number, type, and urgency of pages received and the task being performed at the time of paging by on-call junior neurosurgery residents at a large teaching hospital, with the aim of providing insight into m...

Implementation of a standard protocol and use of antibiotic-coated ventricular catheters helped reduce EVD-related infections from 9.2% to almost zero at the University of Florida. This project demonstrated the success of creating a task force to identify areas of improvement, implement solutions, and monitor the outcomes.

Radiographic response of brain metastasis to stereotactic radiosurgery (SRS) over time has not been well characterized. Being able to predict SRS-induced changes in tumor size over time may allow improved counseling of patients and potentially earlier recognition of poor response to SRS. To quantify the rate of change in size of metastatic brain tu...

Stereotactic radiosurgery is the term coined by Lars Leksell to describe the application of a single, high dose of radiation to a stereotactically defined target volume. In the 1970s, reports began to appear documenting the successful obliteration of arteriovenous malformations (AVMs) with radiosurgery. When an AVM is treated with radiosurgery, a p...

Despite a high success rate in the stereotactic radiosurgical treatment of intracranial arteriovenous malformations (AVMs) that cannot be safely resected with microsurgery, some patients must be managed after treatment failure. To provide an update on the use of repeat linear accelerator radiosurgery as a treatment for failed AVM radiosurgery at th...

The Accreditation Council for Graduate Medical Education (ACGME) duty hour standards that began July 2011 will further limit resident duty hours. To survey neurosurgery residents in the United States on duty hour violations under the current system and the predicted effects on education and patient safety of the new regulations. Surveys were mailed...

Nonvestibular schwannomas are uncommon tumors of the brain often treated by surgical resection. Surgery may be associated with high morbidity. We present a series of nonvestibular schwannomas treated with linear accelerator radiosurgery during a 19-year period. This is a retrospective analysis of patients who underwent treatment of nonvestibular sc...

Disseminated intravascular coagulation is a relatively common complication in patients with trauma, sepsis, obstetric calamities, and certain malignancies. We report a rare case of DIC after embolization and surgery for a large meningioma. We also review the literature on coagulopathy during brain tumor surgery as well as the diagnosis and treatmen...

Intracranial hypotension is not an uncommon diagnosis after lumbar puncture or neurosurgery. However, spontaneous intracranial hypotension (SIH) is a poorly understood entity that can present with a wide variety of symptoms/signs ranging from headache to coma. SIH may result from an occult spinal cerebrospinal fluid (CSF) leak. Alternatively, becau...

In 2004, the Department of Neurosurgery at the University of Florida implemented a major curriculum innovation called the Transition to Practice program. This program was established to prepare residents to more safely transition to the role of independent practitioner. A qualitative and quantitative evaluation of the program was conducted after it...

Image guided surgery is currently performed using frame-based as well as frameless approaches. In order to reduce the invasive nature of stereotactic guidance as well as to reduce the cost in both equipment and time required within the operating room we investigated the use of rapid prototyping (RP) technology. In our approach we fabricated custom...

Neurosurgical patients have a high risk of hyponatremia and associated complications. We critically evaluated the existing literature to identify the determinants for the development of hyponatremia and which management strategies provided the best outcomes. A multidisciplinary panel in the areas of neurosurgery, nephrology, critical care medicine,...

The search for efficacious, minimally invasive neurosurgical treatment has led to the development of the operating microscope, endovascular treatment, and endoscopic surgery. One of the most minimally invasive and exciting discoveries is the use of targeted, high-dose radiation for neurosurgical disorders. Radiosurgery is truly minimally invasive,...

Trigeminal neuralgia, also called tic douloureux, is a commonly misdiagnosed disorder characterized by intense facial pain. It is a chronic pain disorder that affects the fifth cranial nerve, usually in the fifth to seventh decade of life. Medication is the first line of treatment but frequently fails over time. At that point, many patients seek su...

The radiosurgery-based arteriovenous malformation (AVM) score (RBAS) is a grading system designed to predict patient outcomes after Gamma Knife surgery for AVMs. This study seeks to validate independently the predictive nature of the RBAS, not only after single treatment but for retreatment, and to assess the overall outcome regardless of number of...

In this paper, the authors review the results of a single-center experience using linear accelerator (LINAC) radiosurgery for the treatment of cavernous sinus meningiomas. This is a retrospective analysis with a median follow-up of 50 months. All patients were treated on an outpatient basis. Fifty-five patients were treated and 6 patients were lost...

The purpose of this paper is to report on a case of a successful dorsal root entry zone procedure done for the treatment of postherpetic neuralgia and to provide unique MRI documentation outlining the precise location of the surgical lesion. A 79-year-old female presented with postherpetic neuralgia in the left V1 distribution following a herpes zo...

Meningiomas are the most common benign primary brain tumor, with an incidence of approximately 7/100,000 in the general population. Surgery has long been thought to be the treatment of choice for symptomatic lesions and is often curative. Many meningiomas, however, occur in locations where attempted surgical cure may be associated with morbidity or...

Stereotactic radiosurgery (SRS) is a minimally invasive treatment modality that delivers a large single dose of radiation to a specific intracranial target while sparing surrounding tissue. Unlike conventional fractionated radiotherapy, SRS does not maximally exploit the higher radio sensitivity of brain lesions relative to normal brain (therapeuti...

Radiosurgery, a term coined in 1951 by the Swedish neurosurgeon Lars Leksell [1], was first practiced using an orthovoltage x-ray apparatus, then a particle accelerator and finally a Co-60 isotope unit. The majority of Leksell’s clinical work was carried out using the latter device, known as the Gamma Knife. With this dedicated tool Leksell was abl...

Stereotactic radiosurgery is a commonly used treatment method in the management of metastatic brain tumors. When lesions enlarge after radiosurgery, it may represent tumor regrowth, radiation necrosis, or both. The purpose of this study was to determine whether standard magnetic resonance imaging (MRI) sequences could reliably distinguish between t...

Linear accelerator (LINAC) radiosurgery was developed in the 1980s. The treatment paradigm uses the rotating high-energy X-ray output of the LINAC to focus many hundreds of 'beam equivalents' on intracranial or spinal targets. At the University of Florida, 450 vestibular schwannomas have been treated. Tumor control has been achieved in 90% (5- year...

To review one of the largest single-institution experiences treating metastatic brain disease with stereotactic radiosurgery. We performed a retrospective analysis of 619 patients who underwent linear accelerator-based stereotactic radiosurgery for 1569 brain metastases between May 1989 and February 2006. Patient characteristics and treatment param...

Stereotactic radiosurgery (SRS) is a minimally invasive treatment modality that delivers a large, single dose of radiation to a specific intracranial target while sparing surrounding tissue. Unlike conventional fractionated radiotherapy, SRS does not maximally exploit the higher radiosensitivity of brain lesions relative to normal brain (therapeuti...

Acoustic schwannomas are benign tumors that originate from Schwann cells surrounding the vestibular (eighth) nerve, usually within the internal auditory canal [1]. As the tumor enlarges, it fills the canal and extends into the cerebellopontine angle. Acoustic schwannomas are relatively uncommon with an incidence of approximately 1 new case per 100,...

The goal in this study was to review the effects of treatment plan quality on outcomes after radiosurgery for vestibular schwannoma (VS). Between July 1988 and August 2005, 390 patients were treated. The results of this experience have been published recently. In this study the authors looked at dosimetry variables: conformity of treatment plan and...

Purpose:Image guidance allows surgeons to perform accurate and minimally invasive surgical procedures. Advancements in the field of rapid prototyping have provided the opportunity to design patient specific guidance systems. At the University of Florida, this technology has been applied to the fabrication of patient specific routers that allows gui...

Hyperbaric oxygenation is a rarely used method of treatment for steroid-refractory radiation-induced edema after stereotactic radiosurgery. We present its successful implementation for a radiosurgical complication after the treatment of a deep, large arteriovenous malformation. We also review the literature on hyperbaric oxygenation for radiation-i...

Patients with bilateral vestibular schwannomas offer a unique opportunity to determine the effectiveness of radiosurgery. By using the untreated tumor as an internal control, one can determine whether radiosurgery was able to interrupt the natural history of the treated tumor. From September 1998 to November 2004, 13 patients with neurofibromatosis...

The last decade has seen the introduction of advanced technologies that have enabled much more precise application of therapeutic radiation. These relatively new technologies include multileaf collimators, 3-dimensional conformal radiotherapy planning, and intensity modulated radiotherapy in radiotherapy. Therapeutic dose distributions have become...

Full integration of advanced imaging, noninvasive immobilization, positioning, and motion-management methods into radiosurgery have resulted in fundamental changes in therapeutic strategies and approaches that are leading us to the treatment room of the future. With the introduction of image-guided radiosurgery (IGRS) systems, such as Trilogy, phys...

Radiosurgery has become a popular treatment for small vestibular schwannomas (VSs). The aim of this study was to review an extensive, single-institution experience with linear accelerator (LINAC) radiosurgery for VSs. Between July 1988 and August 2005, 390 patients with VSs were treated with LINAC-based radiosurgery at the authors' institution. Pat...

Neurocytomas are typically located within the supratentorial ventricular system. Extraventricular neurocytomas are very rare, and this is only the second reported case of a pontine neurocytoma. We discuss the clinical presentation, histology, and treatment of these rare tumors. A 58-year-old man presented with a 4-month history of headache and unil...

Image‐guided surgery can be broken down into two broad categories: frame‐based guidance and frameless guidance. In order to reduce both the invasive nature of stereotactic guidance and the cost in equipment and time, we have developed a new guidance technique based on rapid prototyping (RP) technology. This new system first builds a computer model...

To review a single-institution's 12-year experience of treating malignant gliomas with linear accelerator-based radiosurgery. One hundred patients were treated for malignant gliomas at the University of Florida between May 1, 1989, and June 12, 2002. Patient variables were entered into a radiosurgery database in a prospective manner. The endpoint o...

In this paper the authors review the results of a single-center experience in the use of linear accelerator (LINAC) surgery for radiosurgical treatment of meningiomas. A retrospective analysis of all patients treated with LINAC surgery for meningiomas between May 1989 and December 2001 was performed. All patients participated in follow-up review fo...