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49-473: AANS may refer to: American Association of Neurological Surgeons , a scientific and educational association focused on advancing the specialty of neurological surgery. The organization has over 8,000 members around the world. Australian Army Nursing Service , an Australian Army Reserve unit which provided a pool of trained civilian nurses who had volunteered for military service during wartime Topics referred to by

98-703: A Linac-based radiosurgical system. Winston and Lutz further advanced Linac-based radiosurgical prototype technologies by incorporating an improved stereotactic positioning device and a method to measure the accuracy of various components. Using a modified Linac, the first patient in the United States was treated in Boston Brigham and Women's Hospital in February 1986. Technological improvements in medical imaging and computing have led to increased clinical adoption of stereotactic radiosurgery and have broadened its scope in

147-549: A dedicated radiosurgery Linac is the CyberKnife , a compact Linac mounted onto a robotic arm that moves around the patient and irradiates the tumor from a large set of fixed positions, thereby mimicking the Gamma Knife concept. The fundamental principle of radiosurgery is that of selective ionization of tissue, by means of high-energy beams of radiation. Ionization is the production of ions and free radicals which are damaging to

196-512: A distinct neurosurgical discipline that utilizes externally generated ionizing radiation to inactivate or eradicate defined targets, typically in the head or spine, without the need for a surgical incision. Irrespective of the similarities between the concepts of stereotactic radiosurgery and fractionated radiotherapy the mechanism to achieve treatment is subtly different, although both treatment modalities are reported to have identical outcomes for certain indications. Stereotactic radiosurgery has

245-457: A greater emphasis on delivering precise, high doses to small areas, to destroy target tissue while preserving adjacent normal tissue. The same principle is followed in conventional radiotherapy although lower dose rates spread over larger areas are more likely to be used (for example as in VMAT treatments). Fractionated radiotherapy relies more heavily on the different radiosensitivity of the target and

294-637: A hemispheric array in a heavily shielded assembly. The device aims gamma radiation through a target point in the patient's brain. The patient wears a specialized helmet that is surgically fixed to the skull, so that the brain tumor remains stationary at the target point of the gamma rays. An ablative dose of radiation is thereby sent through the tumor in one treatment session, while surrounding brain tissues are relatively spared. Gamma Knife therapy, like all radiosurgery, uses doses of radiation to kill cancer cells and shrink tumors, delivered precisely to avoid damaging healthy brain tissue. Gamma Knife radiosurgery

343-417: A medical synchrotron or cyclotron , and accelerated in successive transits through a circular, evacuated conduit or cavity, using powerful magnets to shape their path, until they reach the energy required to just traverse a human body, usually about 200 MeV. They are then released toward the region to be treated in the patient's body, the irradiation target. In some machines, which deliver protons of only

392-712: A professional staff office in Washington, D.C. , the AANS maintains a member-driven Washington Committee to advocate for a number of causes. Washington staff maintains the Neurosurgery Blog which highlights the latest legislative activities affecting health care and the neurosurgical specialty. Since 1944, the AANS has published the Journal of Neurosurgery . In addition, the quarterly AANS Neurosurgeon focuses on "issues related to legislation, workforce and practice management." Each issue

441-476: A recent systematic review found no difference in the affects on overall survival or deaths due to brain metastases when comparing SRS treatment alone to SRS plus WBRT treatment or WBRT alone. Expansion of stereotactic radiotherapy to other lesions is increasing, and includes liver cancer, lung cancer, pancreatic cancer, etc. The New York Times reported in December 2010 that radiation overdoses had occurred with

490-495: A specific energy, a custom mask made of plastic is interposed between the beam source and the patient to adjust the beam energy to provide the appropriate degree of penetration. The phenomenon of the Bragg peak of ejected protons gives proton therapy advantages over other forms of radiation, since most of the proton's energy is deposited within a limited distance, so tissue beyond this range (and to some extent also tissue inside this range)

539-532: Is able to accurately focus many beams of gamma radiation on one or more tumors. Each individual beam is of relatively low intensity, so the radiation has little effect on intervening brain tissue and is concentrated only at the tumor itself. Gamma Knife radiosurgery has proven effective for patients with benign or malignant brain tumors up to 4 cm (1.6 in) in size, vascular malformations such as an arteriovenous malformation (AVM), pain, and other functional problems. For treatment of trigeminal neuralgia

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588-407: Is centered on different themes, and past themes include humanitarian neurosurgery, neurosurgeons as patients, stereotactic radiosurgery , and neurovascular neurosurgery. On its website, the AANS presents information relevant to patients regarding a number of neurosurgical ailments and treatments. In addition to its efforts during National Neurosurgery Awareness Week (which is held in conjunction with

637-485: Is different from Wikidata All article disambiguation pages All disambiguation pages American Association of Neurological Surgeons Founded in 1931, the AANS was originally known as the Harvey Cushing Society, named for the brain surgery pioneer Harvey Cushing . The creation of the society was spurred initially by R. Glen Spurling and William P. Van Wagenen who, with Cushing, acknowledged

686-406: Is mechanically rotated around the patient in a full or partial circle. The table where the patient is lying, the "couch", can also be moved in small linear or angular steps. The combination of the movements of the gantry and of the couch allow the computerized planning of the volume of tissue that is going to be irradiated. Devices with a high energy of 6 MeV are commonly used for the treatment of

735-572: Is spared from the effects of radiation. This property of protons, which has been called the " depth charge effect" by analogy to the explosive weapons used in anti-submarine warfare, allows for conformal dose distributions to be created around even very irregularly shaped targets, and for higher doses to targets surrounded or backstopped by radiation-sensitive structures such as the optic chiasm or brainstem. The development of "intensity modulated" techniques allowed similar conformities to be attained using linear accelerator radiosurgery. As of 2013 there

784-456: Is usually used to treat cancer . Radiosurgery was originally defined by the Swedish neurosurgeon Lars Leksell as "a single high dose fraction of radiation, stereotactically directed to an intracranial region of interest". In stereotactic radiosurgery ( SRS ), the word " stereotactic " refers to a three-dimensional coordinate system that enables accurate correlation of a virtual target seen in

833-496: The cells . These ions and radicals, which may be formed from the water in the cell or biological materials, can produce irreparable damage to DNA, proteins, and lipids, resulting in the cell's death. Thus, biological inactivation is carried out in a volume of tissue to be treated, with a precise destructive effect. The radiation dose is usually measured in grays (one gray (Gy) is the absorption of one joule of energy per kilogram of mass). A unit that attempts to take into account both

882-574: The 21st century. The localization accuracy and precision that are implicit in the word "stereotactic" remain of utmost importance for radiosurgical interventions and are significantly improved via image-guidance technologies such as the N-localizer and Sturm-Pastyr localizer that were originally developed for stereotactic surgery . In the 21st century the original concept of radiosurgery expanded to include treatments comprising up to five fractions , and stereotactic radiosurgery has been redefined as

931-503: The AANS Annual Scientific Meeting and heightens public awareness on topics such as stroke ), the AANS also spearheads Neurosurgery Outreach Month every August, touting the importance of concussion and head-injury prevention at the start of a new school year and season for student athletes. The AANS offers its members a number of educational opportunities, mostly through courses held around the country at various times of

980-417: The AANS Annual Scientific Meeting, honoring the lifetime contribution of members for their surgical, scientific and humanitarian accomplishments. Radiosurgery Radiosurgery is surgery using radiation , that is, the destruction of precisely selected areas of tissue using ionizing radiation rather than excision with a blade. Like other forms of radiation therapy (also called radiotherapy), it

1029-633: The AANS in 1981, the Neurosurgery Research and Education Foundation provides funding for training in the neurosciences and support for career neurosurgeons. Through grants and awards, it supports medical students, residents and young neurosurgical faculty in conducting basic science, patient-oriented, clinical and outcomes research, as well as outcomes studies that protect and support neurosurgical procedures for all practicing neurosurgeons. It also funds North American and international fellowships in all neurosurgical subspecialties. As an effort led by

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1078-558: The AANS with cooperation of other organized neurological associations, the Neuropoint Alliance was founded in 2008 to collect, analyze, and report clinical data from neurosurgical practices. Services include clinical trial management, study design, and survey facilitation. Its first nationwide effort was the National Neurosurgery Quality and Outcomes Database. The AANS presents several major awards each year during

1127-604: The Gamma Knife is dedicated to radiosurgery, many Linacs are built for conventional fractionated radiotherapy and require additional technology and expertise to become dedicated radiosurgery tools. There is not a clear difference in efficacy between these different approaches. The major manufacturers, Varian and Elekta offer dedicated radiosurgery Linacs as well as machines designed for conventional treatment with radiosurgery capabilities. Systems designed to complement conventional Linacs with beam-shaping technology, treatment planning, and image-guidance tools to provide. An example of

1176-597: The Gamma Knife unit and the Cyberknife unit. The highly precise irradiation of targets within the brain and spine is planned using information from medical images that are obtained via computed tomography , magnetic resonance imaging , and angiography . Radiosurgery is indicated primarily for the therapy of tumors, vascular lesions and functional disorders. Significant clinical judgment must be used with this technique and considerations must include lesion type, pathology if available, size, location and age and general health of

1225-522: The Gamma Knife, which was installed at the Karolinska Institute and consisted of several cobalt-60 radioactive sources placed in a kind of helmet with central channels for irradiation with gamma rays. This prototype was designed to produce slit-like radiation lesions for functional neurosurgical procedures to treat pain, movement disorders, or behavioral disorders that did not respond to conventional treatment. The success of this first unit led to

1274-697: The Leksell Gamma Knife) is used to treat brain tumors by administering high-intensity gamma radiation therapy in a manner that concentrates the radiation over a small volume. The device was invented in 1967 at the Karolinska Institute in Stockholm , Sweden, by Lars Leksell , Romanian-born neurosurgeon Ladislau Steiner, and radiobiologist Börje Larsson from Uppsala University , Sweden. A Gamma Knife typically contains 201 cobalt-60 sources of approximately 30  curies each (1.1  TBq ), placed in

1323-426: The brain, due to the depth of the target. The diameter of the energy beam leaving the emission head can be adjusted to the size of the lesion by means of collimators . They may be interchangeable orifices with different diameters, typically varying from 5 to 40 mm in 5 mm steps, or multileaf collimators, which consist of a number of metal leaflets that can be moved dynamically during treatment in order to shape

1372-428: The construction of a second device, containing 179 cobalt-60 sources. This second Gamma Knife unit was designed to produce spherical lesions to treat brain tumors and intracranial arteriovenous malformations (AVMs). Additional units were installed in the 1980s all with 201 cobalt-60 sources. In parallel to these developments, a similar approach was designed for a linear particle accelerator or Linac. Installation of

1421-410: The contribution of the physicists Kurt Liden and Börje Larsson. At this time, stereotactic proton beams had replaced the x-rays. The heavy particle beam presented as an excellent replacement for the surgical knife, but the synchrocyclotron was too clumsy. Leksell proceeded to develop a practical, compact, precise and simple tool which could be handled by the surgeon himself. In 1968 this resulted in

1470-608: The different organs that are irradiated and the type of radiation is the sievert , a unit that describes both the amount of energy deposited and the biological effectiveness. When used outside the CNS it may be called stereotactic body radiation therapy (SBRT) or stereotactic ablative radiotherapy (SABR). Radiosurgery is performed by a multidisciplinary team of neurosurgeons , radiation oncologists and medical physicists to operate and maintain highly sophisticated, highly precise and complex instruments, including medical linear accelerators,

1519-443: The electrodes with radiation was made in the early fifties, with x-rays . The principle of this instrument was to hit the intra-cranial target with narrow beams of radiation from multiple directions. The beam paths converge in the target volume, delivering a lethal cumulative dose of radiation there, while limiting the dose to the adjacent healthy tissue. Ten years later significant progress had been made, due in considerable measure to

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1568-660: The first 4  MeV clinical linear accelerator began in June 1952 in the Medical Research Council (MRC) Radiotherapeutic Research Unit at the Hammersmith Hospital , London. The system was handed over for physics and other testing in February 1953 and began to treat patients on 7 September that year. Meanwhile, work at the Stanford Microwave Laboratory led to the development of a 6 MeV accelerator, which

1617-565: The linear accelerator method of radiosurgery, due in large part to inadequate safeguards in equipment retrofitted for stereotactic radiosurgery. In the U.S. the Food and Drug Administration (FDA) regulates these devices, whereas the Gamma Knife is regulated by the Nuclear Regulatory Commission . This is evidence that immunotherapy may be useful for treatment of radiation necrosis following stereotactic radiotherapy. The selection of

1666-652: The need for a venue in which younger neurosurgeons could exchange ideas on the specialty. Membership to the Society of Neurological Surgeons, the specialty's key organization during this period, was closed to younger men at this time. Spurling and Van Wagenen enlisted the help of Temple Fay and R. Eustace Semmes in the creation of the group, and on May 6, 1932, the Harvey Cushing Society held its first meeting in Boston . Twenty-three people attended, many of whom were Cushing's colleagues and neurosurgical trainees. Other charter members of

1715-558: The patient's diagnostic images with the actual target position in the patient. Stereotactic radiosurgery may also be called stereotactic body radiation therapy (SBRT) or stereotactic ablative radiotherapy (SABR) when used outside the central nervous system (CNS). Stereotactic radiosurgery was first developed in 1949 by the Swedish neurosurgeon Lars Leksell to treat small targets in the brain that were not amenable to conventional surgery. The initial stereotactic instrument he conceived used probes and electrodes. The first attempt to supplant

1764-428: The patient. General contraindications to radiosurgery include excessively large size of the target lesion, or lesions too numerous for practical treatment. Patients can be treated within one to five days as outpatients . By comparison, the average hospital stay for a craniotomy (conventional neurosurgery, requiring the opening of the skull) is about 15 days. The radiosurgery outcome may not be evident until months after

1813-422: The procedure may be used repeatedly on patients. Acute complications following Gamma Knife radiosurgery are rare, and complications are related to the condition being treated. A linear accelerator (linac) produces x-rays from the impact of accelerated electrons striking a high z target, usually tungsten. The process is also referred to as "x-ray therapy" or "photon therapy." The emission head, or " gantry ",

1862-435: The proper kind of radiation and device depends on many factors including lesion type, size, and location in relation to critical structures. Data suggest that similar clinical outcomes are possible with all of the various techniques. More important than the device used are issues regarding indications for treatment, total dose delivered, fractionation schedule and conformity of the treatment plan. A Gamma Knife (also known as

1911-447: The radiation beam to conform to the mass to be ablated. As of 2017 Linacs were capable of achieving extremely narrow beam geometries, such as 0.15 to 0.3 mm. Therefore, they can be used for several kinds of surgeries which hitherto had been carried out by open or endoscopic surgery, such as for trigeminal neuralgia. Long-term follow-up data has shown it to be as effective as radiofrequency ablation, but inferior to surgery in preventing

1960-432: The recurrence of pain. The first such systems were developed by John R. Adler , a Stanford University professor of neurosurgery and radiation oncology, and Russell and Peter Schonberg at Schonberg Research, and commercialized under the brand name CyberKnife. Protons may also be used in radiosurgery in a procedure called Proton Beam Therapy (PBT) or proton therapy . Protons are extracted from proton donor materials by

2009-405: The same term [REDACTED] This disambiguation page lists articles associated with the title AANS . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=AANS&oldid=1027137274 " Category : Disambiguation pages Hidden categories: Short description

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2058-472: The society were Gilbert Anderson, Paul C. Bucy , W. Edward Chamberlain, Leo M. Davidoff , Louise Eisenhardt, Edgar Fincher, John F. Fulton, W. James Gardner, William J. German, Franc D. Ingraham, Franklin Jelsma, Edgar Kahn, Roland Klemme, James G. Lyerly Sr., Eric Oldberg, Tracy Putnam , Frederic Schreiber, Merril C. Sosman, and Frank R. Teachenor. The AANS is composed of board-certified neurosurgeons from around

2107-545: The spinal metastasis is efficient in controlling pain in up to 90% of the cases and ensures stability of the tumours on imaging evaluation in 95% of the cases, and is more efficient for spinal metastasis involving one or two segments. Meanwhile, conventional external beam radiotherapy is more suitable for multiple spinal involvement. SRS may be administered alone or in combination with other therapies. For brain metastases, these treatment options include whole brain radiation therapy (WBRT), surgery, and systemic therapies. However,

2156-694: The surrounding normal tissue to the total accumulated radiation dose . Historically, the field of fractionated radiotherapy evolved from the original concept of stereotactic radiosurgery following discovery of the principles of radiobiology : repair, reassortment, repopulation, and reoxygenation. Today, both treatment techniques are complementary, as tumors that may be resistant to fractionated radiotherapy may respond well to radiosurgery, and tumors that are too large or too close to critical organs for safe radiosurgery may be suitable candidates for fractionated radiotherapy. Today, both Gamma Knife and Linac radiosurgery programs are commercially available worldwide. While

2205-433: The treatment. Since radiosurgery does not remove the tumor but inactivates it biologically, lack of growth of the lesion is normally considered to be treatment success. General indications for radiosurgery include many kinds of brain tumors, such as acoustic neuromas , germinomas , meningiomas , metastases , trigeminal neuralgia, arteriovenous malformations, and skull base tumors, among others. Stereotatic radiosurgery of

2254-499: The world as well as medical students, neurosurgical support staff, and physicians in associated fields of practice. Throughout its history, the AANS has taken stances on a number of key legislative issues affecting neurosurgical professionals and their patients. Efforts include patient safety and quality improvement, tort reform , and issues relating to the Emergency Medical Treatment and Active Labor Act . In addition to

2303-465: The year. Topics include practice management, oral board preparation, maintenance of certification, and resident education. Course offerings also extend to mid-level practitioners such as nurses and physician assistants . The AANS has held an Annual Scientific Meeting every year since its 1932 inception except twice; in 1945 due to World War II , and in 2020 due to the COVID-19 pandemic . The 2021 meeting

2352-505: Was exclusively virtual, also due to the pandemic. Programming includes presentations of neurological studies, seminars, workshops for practitioners at all levels, and keynote speeches. Past speakers include H. Ross Perot (1987), Colin Powell (1995), George H. W. Bush (1999), Tom Brokaw (2001), Benazir Bhutto (2002), Henry Kissinger (2003), Ken Burns (2004), Walter Isaacson (2013), and Chesley Sullenberger (2013). Established by

2401-514: Was installed at Stanford University Hospital, California, in 1956. Linac units quickly became favored devices for conventional fractionated radiotherapy but it lasted until the 1980s before dedicated Linac radiosurgery became a reality. In 1982, the Spanish neurosurgeon J. Barcia-Salorio began to evaluate the role of cobalt-generated and then Linac-based photon radiosurgery for the treatment of AVMs and epilepsy . In 1984, Betti and Derechinsky described

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