The Neurologic & Orthopedic Hospital of Chicago (or NOHC ) was a medical center from 1987 to 2009.
88-440: NOHC was an eight-storey hospital with approximately 200,000 square feet (19,000 m), with all services conveniently located off of a central elevator bank. It had 10 operating rooms, 52 medical/surgical beds, 15 rehabilitation beds, and 18 intensive care beds. NOHC was also equipped with state-of-the-art medical equipment, including a stereotactic radiosurgery suite ( Gamma Knife ), a neuroangiography suite (Siemen's Biplane), and
176-430: A Helium ion with a +2 charge (missing its two electrons). If the ion gains electrons from its environment, the alpha particle can be written as a normal (electrically neutral) helium atom 2 He . Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei , such as potassium-40 . The production of beta particles is termed beta decay . They are designated by
264-516: A blade. Like other forms of radiation therapy (also called radiotherapy), it 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
352-451: A close second. Other stochastic effects of ionizing radiation are teratogenesis , cognitive decline , and heart disease . Although DNA is always susceptible to damage by ionizing radiation, the DNA molecule may also be damaged by radiation with enough energy to excite certain molecular bonds to form pyrimidine dimers . This energy may be less than ionizing, but near to it. A good example
440-560: A comprehensive diagnostic imaging suite (1.5 MRI, CT and general x-ray). In 2009 the hospital closed and the doctors merged with NorthShore University HealthSystem . Dr. Leonard J. Cerullo founded the Chicago Institute of Neurosurgery and Neuroresearch Medical Group (“CINN”) in 1987 and oversaw its growth into one of the largest physician practices specializing in neurologic care in the Midwest. Dr. Cerullo's original vision
528-506: A compromise that has shifted over time. For example, at one time, assistants in shoe shops in the US used X-rays to check a child's shoe size , but this practice was halted when the risks of ionizing radiation were better understood. Neutron radiation is essential to the working of nuclear reactors and nuclear weapons . The penetrating power of x-ray, gamma, beta, and positron radiation is used for medical imaging , nondestructive testing , and
616-561: 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
704-512: 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
792-635: A fast recoil proton that ionizes in turn. At the end of its path, the neutron is captured by a nucleus in an (n,γ)-reaction that leads to the emission of a neutron capture photon. Such photons always have enough energy to qualify as ionizing radiation. Neutron radiation, alpha radiation, and extremely energetic gamma (> ~20 MeV) can cause nuclear transmutation and induced radioactivity . The relevant mechanisms are neutron activation , alpha absorption , and photodisintegration . A large enough number of transmutations can change macroscopic properties and cause targets to become radioactive themselves, even after
880-495: A gas per ion pair formed , which combines ionization energy plus the energy lost to other processes such as excitation . At 38 nanometers wavelength for electromagnetic radiation , 33 eV is close to the energy at the conventional 10 nm wavelength transition between extreme ultraviolet and X-ray radiation, which occurs at about 125 eV. Thus, X-ray radiation is always ionizing, but only extreme-ultraviolet radiation can be considered ionizing under all definitions. Neutrons have
968-461: 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
SECTION 10
#17327903066391056-637: 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
1144-403: A larger amount of ionization from the daughter products of fission. Outside the nucleus, free neutrons are unstable and have a mean lifetime of 14 minutes, 42 seconds. Free neutrons decay by emission of an electron and an electron antineutrino to become a proton, a process known as beta decay : In the adjacent diagram, a neutron collides with a proton of the target material, and then becomes
1232-408: 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 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
1320-403: A low-energy electron, annihilation occurs, resulting in their conversion into the energy of two or more gamma ray photons (see electron–positron annihilation ). As positrons are positively charged particles they can directly ionize an atom through Coulomb interactions. Positrons can be generated by positron emission nuclear decay (through weak interactions ), or by pair production from
1408-449: A lower energy than gamma rays, and an older convention was to define the boundary as a wavelength of 10 m (or a photon energy of 100 keV). That threshold was driven by historic limitations of older X-ray tubes and low awareness of isomeric transitions . Modern technologies and discoveries have shown an overlap between X-ray and gamma energies. In many fields they are functionally identical, differing for terrestrial studies only in origin of
1496-417: 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
1584-436: A neutral electrical charge often misunderstood as zero electrical charge and thus often do not directly cause ionization in a single step or interaction with matter. However, fast neutrons will interact with the protons in hydrogen via linear energy transfer , energy that a particle transfers to the material it is moving through. This mechanism scatters the nuclei of the materials in the target area, causing direct ionization of
1672-416: A proton emission forming nitrogen-16 , which decays to oxygen-16. The short-lived nitrogen-16 decay emits a powerful beta ray. This process can be written as: O (n,p) N (fast neutron capture possible with >11 MeV neutron) N → O + β (Decay t 1/2 = 7.13 s) This high-energy β further interacts rapidly with other nuclei, emitting high-energy γ via Bremsstrahlung While not a favorable reaction,
1760-676: A protracted time can cause cancer . The International Commission on Radiological Protection (ICRP) issues guidance on ionizing radiation protection, and the effects of dose uptake on human health. Ionizing radiation may be grouped as directly or indirectly ionizing. Any charged particle with mass can ionize atoms directly by fundamental interaction through the Coulomb force if it carries sufficient kinetic energy. Such particles include atomic nuclei , electrons , muons , charged pions , protons , and energetic charged nuclei stripped of their electrons. When moving at relativistic speeds (near
1848-481: 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
SECTION 20
#17327903066391936-499: 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)
2024-496: A sufficiently energetic photon . Positrons are common artificial sources of ionizing radiation used in medical positron emission tomography (PET) scans. Charged nuclei are characteristic of galactic cosmic rays and solar particle events and except for alpha particles (charged helium nuclei) have no natural sources on earth. In space, however, very high energy protons, helium nuclei, and HZE ions can be initially stopped by relatively thin layers of shielding, clothes, or skin. However,
2112-419: A variety of industrial gauges. Radioactive tracers are used in medical and industrial applications, as well as biological and radiation chemistry . Alpha radiation is used in static eliminators and smoke detectors . The sterilizing effects of ionizing radiation are useful for cleaning medical instruments, food irradiation , and the sterile insect technique . Measurements of carbon-14 , can be used to date
2200-417: A virtual target seen in 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
2288-615: Is a particular hazard in semiconductor microelectronics employed in electronic equipment, with subsequent currents introducing operation errors or even permanently damaging the devices. Devices intended for high radiation environments such as the nuclear industry and extra-atmospheric (space) applications may be made radiation hard to resist such effects through design, material selection, and fabrication methods. Proton radiation found in space can also cause single-event upsets in digital circuits. The electrical effects of ionizing radiation are exploited in gas-filled radiation detectors, e.g.
2376-532: 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
2464-735: Is also the former team physician for the Chicago Bulls and is a current league physician for the NBA. Preston Wolin, director of sports medicine, is also the former team physician for Major League Soccer's Chicago Fire. NOHC was the nation's first hospital dedicated exclusively to the diagnosis, treatment, and rehabilitation of neurological and orthopedic patients. From October 2006 to September 2007, NOHC performed over 1,100 neurosurgical cases, 910 orthopedic cases and 1650 pain procedures. NOHC physicians took part in studies that lead to new treatment options for challenging conditions. They were among
2552-619: Is closest to visible energies, have been proven to result in formation of reactive oxygen species in skin, which cause indirect damage since these are electronically excited molecules which can inflict reactive damage, although they do not cause sunburn (erythema). Like ionization-damage, all these effects in skin are beyond those produced by simple thermal effects. The table below shows radiation and dose quantities in SI and non-SI units. Ionizing radiation has many industrial, military, and medical uses. Its usefulness must be balanced with its hazards,
2640-541: Is dependent on the speed of the neutron, whether fast or thermal or somewhere in between. It is also dependent on the nuclei it strikes and its neutron cross section . In inelastic scattering, neutrons are readily absorbed in a type of nuclear reaction called neutron capture and attributes to the neutron activation of the nucleus. Neutron interactions with most types of matter in this manner usually produce radioactive nuclei. The abundant oxygen-16 nucleus, for example, undergoes neutron activation, rapidly decays by
2728-406: 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
Neurologic & Orthopedic Hospital of Chicago - Misplaced Pages Continue
2816-415: Is of concern when shielding beta emitters, as the interaction of beta particles with some shielding materials produces Bremsstrahlung. The effect is greater with material having high atomic numbers, so material with low atomic numbers is used for beta source shielding. The positron or antielectron is the antiparticle or the antimatter counterpart of the electron . When a low-energy positron collides with
2904-578: Is significantly absorbed by the Earth's atmosphere, which is a radiation shield equivalent to about 10 meters of water. The alpha particle was named by Ernest Rutherford after the first letter in the Greek alphabet , α , when he ranked the known radioactive emissions in descending order of ionising effect in 1899. The symbol is α or α . Because they are identical to helium nuclei, they are also sometimes written as He or 2 He indicating
2992-572: 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
3080-471: Is the dominant mechanism in organic materials for photon energies below 100 keV, typical of classical X-ray tube originated X-rays . At energies beyond 100 keV, photons ionize matter increasingly through the Compton effect , and then indirectly through pair production at energies beyond 5 MeV. The accompanying interaction diagram shows two Compton scatterings happening sequentially. In every scattering event,
3168-614: Is ultraviolet spectrum energy which begins at about 3.1 eV (400 nm) at close to the same energy level which can cause sunburn to unprotected skin, as a result of photoreactions in collagen and (in the UV-B range) also damage in DNA (for example, pyrimidine dimers). Thus, the mid and lower ultraviolet electromagnetic spectrum is damaging to biological tissues as a result of electronic excitation in molecules which falls short of ionization, but produces similar non-thermal effects. To some extent, visible light and also ultraviolet A (UVA) which
3256-401: Is used in a wide variety of fields such as medicine , nuclear power , research, and industrial manufacturing, but presents a health hazard if proper measures against excessive exposure are not taken. Exposure to ionizing radiation causes cell damage to living tissue and organ damage . In high acute doses, it will result in radiation burns and radiation sickness , and lower level doses over
3344-523: Is well understood, but quantitative models predicting the level of risk remain controversial. The most widely accepted model, the Linear no-threshold model (LNT), holds that the incidence of cancers due to ionizing radiation increases linearly with effective radiation dose at a rate of 5.5% per sievert . If this is correct, then natural background radiation is the most hazardous source of radiation to general public health, followed by medical imaging as
3432-535: The Chernobyl disaster . Monatomic fluids, e.g. molten sodium , have no chemical bonds to break and no crystal lattice to disturb, so they are immune to the chemical effects of ionizing radiation. Simple diatomic compounds with very negative enthalpy of formation , such as hydrogen fluoride will reform rapidly and spontaneously after ionization. The ionization of materials temporarily increases their conductivity, potentially permitting damaging current levels. This
3520-521: The Geiger-Muller counter or the ion chamber . Most adverse health effects of exposure to ionizing radiation may be grouped in two general categories: The most common impact is stochastic induction of cancer with a latent period of years or decades after exposure. For example, ionizing radiation is one cause of chronic myelogenous leukemia , although most people with CML have not been exposed to radiation. The mechanism by which this occurs
3608-478: The Greek letter beta (β). There are two forms of beta decay, β and β , which respectively give rise to the electron and the positron. Beta particles are much less penetrating than gamma radiation, but more penetrating than alpha particles. High-energy beta particles may produce X-rays known as bremsstrahlung ("braking radiation") or secondary electrons ( delta ray ) as they pass through matter. Both of these can cause an indirect ionization effect. Bremsstrahlung
Neurologic & Orthopedic Hospital of Chicago - Misplaced Pages Continue
3696-413: The O (n,p) N reaction is a major source of X-rays emitted from the cooling water of a pressurized water reactor and contributes enormously to the radiation generated by a water-cooled nuclear reactor while operating. For the best shielding of neutrons, hydrocarbons that have an abundance of hydrogen are used. In fissile materials, secondary neutrons may produce nuclear chain reactions , causing
3784-496: 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
3872-651: The speed of light , c) these particles have enough kinetic energy to be ionizing, but there is considerable speed variation. For example, a typical alpha particle moves at about 5% of c, but an electron with 33 eV (just enough to ionize) moves at about 1% of c. Two of the first types of directly ionizing radiation to be discovered are alpha particles which are helium nuclei ejected from the nucleus of an atom during radioactive decay, and energetic electrons, which are called beta particles . Natural cosmic rays are made up primarily of relativistic protons but also include heavier atomic nuclei like helium ions and HZE ions . In
3960-480: 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 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
4048-754: 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 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
4136-580: 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
4224-604: 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
4312-603: 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
4400-720: 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
4488-610: The Stanford Microwave Laboratory led to the development of a 6 MeV accelerator, which 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
SECTION 50
#17327903066394576-477: The UK), including nuclear radiation , consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light , and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum . Gamma rays , X-rays , and the higher energy ultraviolet part of
4664-416: The activation energy required for the reaction. Optical materials deteriorate under the effect of ionizing radiation. High-intensity ionizing radiation in air can produce a visible ionized air glow of telltale bluish-purple color. The glow can be observed, e.g., during criticality accidents , around mushroom clouds shortly after a nuclear explosion , or the inside of a damaged nuclear reactor like during
4752-466: The atmosphere such particles are often stopped by air molecules, and this produces short-lived charged pions, which soon decay to muons, a primary type of cosmic ray radiation that reaches the surface of the earth. Pions can also be produced in large amounts in particle accelerators . Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus . Alpha particle emissions are generally produced in
4840-425: The brain that were not amenable to conventional surgery. The initial stereotactic instrument he conceived used probes and electrodes. The first attempt to supplant 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
4928-426: 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
5016-429: The bulk of the ionization effects are due to secondary ionization. Even though photons are electrically neutral, they can ionize atoms indirectly through the photoelectric effect and the Compton effect . Either of those interactions will cause the ejection of an electron from an atom at relativistic speeds, turning that electron into a beta particle (secondary beta particle) that will ionize other atoms. Since most of
5104-672: The decay of radioactive isotopes are the primary sources of natural ionizing radiation on Earth, contributing to background radiation . Ionizing radiation is also generated artificially by X-ray tubes , particle accelerators , and nuclear fission . Ionizing radiation is not immediately detectable by human senses, so instruments such as Geiger counters are used to detect and measure it. However, very high energy particles can produce visible effects on both organic and inorganic matter (e.g. water lighting in Cherenkov radiation ) or humans (e.g. acute radiation syndrome ). Ionizing radiation
5192-611: 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,
5280-980: The electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet , visible light , nearly all types of laser light, infrared , microwaves , and radio waves are non-ionizing radiation . The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at different energies . The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV. Ionizing subatomic particles include alpha particles , beta particles , and neutrons . These particles are created by radioactive decay , and almost all are energetic enough to ionize. There are also secondary cosmic particles produced after cosmic rays interact with Earth's atmosphere, including muons , mesons , and positrons . Cosmic rays may also produce radioisotopes on Earth (for example, carbon-14 ), which in turn decay and emit ionizing radiation. Cosmic rays and
5368-428: The energy of the first ball divided between the two unequally. When a charged nucleus strikes a relatively slow-moving nucleus of an object in space, LET occurs and neutrons, alpha particles, low-energy protons, and other nuclei will be released by the collisions and contribute to the total absorbed dose of tissue. Indirectly ionizing radiation is electrically neutral and does not interact strongly with matter, therefore
SECTION 60
#17327903066395456-455: The first ionization energy of oxygen, and the ionization energy of hydrogen, both about 14 eV. In some Environmental Protection Agency references, the ionization of a typical water molecule at an energy of 33 eV is referenced as the appropriate biological threshold for ionizing radiation: this value represents the so-called W-value , the colloquial name for the ICRU 's mean energy expended in
5544-407: The first in the nation to use technologies that later became standards of care: guided imaging in spine surgery, implanted artificial discs, inserted stents and coils designed to keep blood vessels open, and use of the Gamma Knife to destroy tumors. They were developing new knee and hip replacement options that allow patients to resume an active lifestyle. Offered at NOHC, BIRMINGHAM Hip resurfacing
5632-433: The gamma ray transfers energy to an electron, and it continues on its path in a different direction and with reduced energy. The lowest ionization energy of any element is 3.89 eV, for caesium . However, US Federal Communications Commission material defines ionizing radiation as that with a photon energy greater than 10 eV (equivalent to a far ultraviolet wavelength of 124 nanometers ). Roughly, this corresponds to both
5720-484: The hydrogen atoms. When neutrons strike the hydrogen nuclei, proton radiation (fast protons) results. These protons are themselves ionizing because they are of high energy, are charged, and interact with the electrons in matter. Neutrons that strike other nuclei besides hydrogen will transfer less energy to the other particle if linear energy transfer does occur. But, for many nuclei struck by neutrons, inelastic scattering occurs. Whether elastic or inelastic scatter occurs
5808-400: The ionized atoms are due to the secondary beta particles, photons are indirectly ionizing radiation. Radiated photons are called gamma rays if they are produced by a nuclear reaction , subatomic particle decay, or radioactive decay within the nucleus. They are called x-rays if produced outside the nucleus. The generic term "photon" is used to describe both. X-rays normally have
5896-400: The joint replacement department claims one of the lowest infection rates in the nation. 41°57′50.2″N 87°40′37.7″W / 41.963944°N 87.677139°W / 41.963944; -87.677139 Gamma Knife Radiosurgery is surgery using radiation , that is, the destruction of precisely selected areas of tissue using ionizing radiation rather than excision with
5984-581: 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
6072-479: The original source is removed. Ionization of molecules can lead to radiolysis (breaking chemical bonds), and formation of highly reactive free radicals . These free radicals may then react chemically with neighbouring materials even after the original radiation has stopped. (e.g., ozone cracking of polymers by ozone formed by ionization of air). Ionizing radiation can also accelerate existing chemical reactions such as polymerization and corrosion, by contributing to
6160-428: 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
6248-422: 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 ",
6336-576: The process of alpha decay . Alpha particles are a strongly ionizing form of radiation, but when emitted by radioactive decay they have low penetration power and can be absorbed by a few centimeters of air, or by the top layer of human skin. More powerful alpha particles from ternary fission are three times as energetic, and penetrate proportionately farther in air. The helium nuclei that form 10–12% of cosmic rays, are also usually of much higher energy than those produced by radioactive decay and pose shielding problems in space. However, this type of radiation
6424-435: 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
6512-447: 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
6600-545: The radiation. In astronomy, however, where radiation origin often cannot be reliably determined, the old energy division has been preserved, with X-rays defined as being between about 120 eV and 120 keV, and gamma rays as being of any energy above 100 to 120 keV, regardless of source. Most astronomical " gamma-ray astronomy " are known not to originate in nuclear radioactive processes but, rather, result from processes like those that produce astronomical X-rays, except driven by much more energetic electrons. Photoelectric absorption
6688-432: 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
6776-453: The remains of long-dead organisms (such as wood that is thousands of years old). Ionizing radiation is generated through nuclear reactions, nuclear decay, by very high temperature, or via acceleration of charged particles in electromagnetic fields. Natural sources include the sun, lightning and supernova explosions. Artificial sources include nuclear reactors, particle accelerators, and x-ray tubes . The United Nations Scientific Committee on
6864-452: The resulting interaction will generate secondary radiation and cause cascading biological effects. If just one atom of tissue is displaced by an energetic proton, for example, the collision will cause further interactions in the body. This is called " linear energy transfer " (LET), which utilizes elastic scattering . LET can be visualized as a billiard ball hitting another in the manner of the conservation of momentum , sending both away with
6952-545: 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,
7040-694: 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
7128-746: The treatment of AVMs and epilepsy . In 1984, Betti and Derechinsky described 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
7216-433: 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
7304-619: The use of a knee-preserving resurfacing procedure called “The Journey Deuce.” NOHC was named by HealthGrades in 2008 as the best hospital in Illinois for spine surgery, and given 5 stars for back and neck surgery, spinal fusion , and the Spine Surgery Excellence Award 2008, placing it in the top 5% of the country. The same study also noted that patients who undergo brain or spine surgery at NOHC frequently have fewer complications and shorter hospital stays, and that
7392-528: Was a relatively new procedure approved by the FDA in 2006. It is a minimally invasive alternative to total hip replacement that preserves the top of the femur with a metal ball. Dr. Mitchell Sheinkop , director of the joint replacement program, has performed this procedure on former MLB player Albert Belle and former NFL quarterback Jim Miller . He was also the first orthopedic surgeon in Chicago to be trained in
7480-491: 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 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
7568-586: Was led by CINN (Chicago Institute of Neurosurgery and Neuroresearch), which consisted of 9 neurosurgeons, 2 neurologists, 1 neurointerventionalist, and 5 physiatrists. While NOHC acted as the “hub,” CINN also maintained satellite offices at four other locations throughout Chicago. Dr. John Hefferon , one of the leading orthopedic physicians in Chicago, was the Medical Director for NOHC's orthopedic service line that focuses on sports medicine, joint replacement & resurfacing, and work-related injuries. He
7656-400: Was no evidence that proton beam therapy is better than any other types of treatment in most cases, except for a "handful of rare pediatric cancers". Critics, responding to the increasing number of very expensive PBT installations, spoke of a "medical arms race " and "crazy medicine and unsustainable public policy". Ionizing radiation Ionizing radiation (US, ionising radiation in
7744-460: Was to create a hospital dedicated to neurologic care with the founding of the Neurologic & Orthopedic Institute of Chicago in 2003. In 2007, the name was changed to “Neurologic and Orthopedic Hospital of Chicago.” The hospital closed suddenly in 2009. NOHC's medical staff included a number of the most respected neurological and orthopedic physicians in the market. The neurological practice
#638361