NationMaster - Encyclopedia: Radiosurgery

Radiosurgery is a medical procedure which allows non-invasive brain surgery, i.e., without actually opening the skull, by means of directed beams of ionizing radiation. It is a relatively recent technique (1951), which is used to destroy, by means of a precise dosage of radiation, intracranial tumors and other lesions that could be otherwise inaccessible or inadequate for open surgery. There are many nervous diseases for which conventional surgical treatment is difficult or has many deleterious consequences for the patient, due to arteries, nerves, and other vital structures being damaged. A medical procedure is a course of action intended to achieve a result in the care of patients, used by medical or paramedical personnel. ... The term non-invasive in medicine has two meanings: A medical procedure which does not penetrate or break the skin or a body cavity, i. ... Insertion of an electrode during neurosurgery for Parkinsons disease. ... It has been suggested that temporal fenestra be merged into this article or section. ... Radiation hazard symbol. ... 1951 (MCMLI) was a common year starting on Monday; see its calendar. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... This is a list of major and frequently observed neurological disorders (e. ... Section of an artery An artery or arterial is also a class of highway. ... A nerve is an enclosed, cable-like bundle of nerve fibers or axons, which includes the glia that ensheath the axons in myelin. ...

Definition and applications

Doctors make use of highly sophisticated, highly precise and complex instruments, such as stereotactic devices, linear accelerators, computers and laser beams. In the last 20 years, radiosurgery has been used as a first approach, by exclusion or failure of other techniques or as supplements to them, such as other kinds of brain surgery, chemotherapy and radiotherapy. The highly precise irradiation of targets within the brain is planned by the surgeon and medical physicist with basis on images, such as computed tomography (CT), magnetic resonance imaging (MRI), and angiography of the brain. The radiation is applied from an external source, under precise mechanical orientation by a specialized apparatus. Multiple beams are directed (collimated) and centered at the intracranial lesion to be treated. In this way, healthy tissues around the target are preserved. Stereotactic surgery is a minimally-invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the body and to perform on them some action such as ablation (removal), biopsy, lesion, injection, stimulation, implantation, etc. ... A Linear particle accelerator is an electrical device for the acceleration of subatomic particles. ... A BlueGene supercomputer cabinet. ... Experiment with a laser (likely an argon type) (US Military) In physics, a laser is a device that emits light through a specific mechanism for which the term laser is an acronym: light amplification by stimulated emission of radiation. ... Chemotherapy is the use of chemical substances to treat disease. ... Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... This article does not cite its references or sources. ... Magnetic Resonance Image showing a median sagittal cross section through a human head. ... Angiography or arteriography is a medical imaging technique in which an X-ray picture is taken to visualize the inner opening of blood filled structures, including arteries, veins and the heart chambers. ...

Patients can be treated within one day of hospital stay, or even as outpatients. By comparison, the average hospital stay for a craniotomy (conventional neurosurgery, requiring the opening of the skull) is about 15 days. Radiosurgery costs about the same as a conventional surgery, but it avoids mortality, pain and post-surgical complications, such as hemorrhage and infection. The period of recovery is minimal, and in the day following the treatment the patient may return to his or her normal life style, without any discomfort. The major disadvantage of radiosurgery in relation to open surgery (craniotomy) is the duration of time required to achieve the desired effects, while its non-invasive character is perhaps its major advantage. A craniotomy is a surgical operation in which part of the skull (part of the cranium) is removed in order to access the brain. ... Hurting redirects here. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... An infection is the detrimental colonization of a host organism by a foreign species. ...

History

Radiosurgery started with Dr. Lars Leksell from the Karolinska Institute of Stockholm, Sweden, in 1949, in a joint development with Bjorn Larsson, a radiobiologist from Uppsala University. Leksell initially used protons from a cyclotron to irradiate brain tumor lesions. Lars Leksell (1907-1986) was a Swedish physician and Professor of Neurosurgery at the Karolinska Institute in Stockholm, Sweden. ... The Karolinska Institute or Karolinska institutet is a medical university in Stockholm, Sweden. ... Nickname: Location of Stockholm in northern Europe Coordinates: Country Sweden Municipality Stockholm Municipality County Stockholm Province SÃ¶dermanland and Uppland Charter 13th Century Population (April 2007) - City 782,885 - Density 4,160/kmÂ² (10,774. ... Radiation biology is the interdisciplinary field of science that studies the biological effects of ionizing and non-ionizing radiation of the whole electromagnetic spectrum, including radioactivity (alpha, beta and gamma), x-rays, ultraviolet radiation, visible light, microwaves, radio wave, low-frequency radiation (such as used in alternate electric transmission, ultrasound... Uppsala University (Swedish Uppsala universitet) is a public university in Uppsala, Sweden. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... A pair of Dee electrodes with loops of coolant pipes on their surface at the Lawrence Hall of Science. ... A brain tumor is any intracranial tumor created by abnormal and uncontrolled cell division, normally either found in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland...

In 1968, they developed the Gamma Knife, a new device exclusively for radiosurgery, which consisted of radioactive sources of Cobalt-60 placed in a kind of helmet with central channels for irradiation, using gamma rays. In the last version of this device, 201 sources of radioactive cobalt direct gamma radiation to the center of a helmet, where the patient's head is inserted. In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... wikipedia sucks big balls For other uses, see Cobalt (disambiguation). ... This article is about electromagnetic radiation. ...

In order to achieve a high degree of precision, the patient's head is placed on a rigid frame of reference called a stereotactic frame that is inserted into a metal helmet. The device utilizes a coordinate system for each structure of the brain. By consulting a published cranial 'atlas', the surgeon knows the precise point of gamma ray convergance. Stereotactic surgery is a minimally-invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the body and to perform on them some action such as ablation (removal), biopsy, lesion, injection, stimulation, implantation, etc. ...

Gamma Knife surgery is used for stereotactic surgery as a relatively safe and selective method to irradiate tumors and arteriovenous malformations of the brain. The Gamma Knife requires only a single treatment session on a single day. In fact, the Gamma Knife surgery is so established that all insurance providers cover it and Medicare has given it its own authorization code.^{[citation needed]} In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... Stereotactic surgery or stereotaxy is a minimally-invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the body and to perform on them some action such as ablation (removal), biopsy, lesion, injection, stimulation, implantation, radiosurgery etc. ... Arteriovenous malformation or AVM is a congenital disorder of the veins and arteries that make up the vascular system . ... In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... President Johnson signing the Medicare amendment. ...

LINAC is another type of radiosurgery which has enjoyed great dissemination in neurosurgury. It was developed at the University of Florida College of Medicine and introduced by Betti and Colombo in the mid 1980's and utilizes a linear accelerator. High energy, narrowly focused beams of x-rays are employed. 1980 (MCMLXXX) was a leap year starting on Tuesday. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...

This system differs from the Gamma Knife in the way the radiation beams are delivered to the patient's head. In a similar way, a stereotactic device is used to provide a geometric coordinates reference, but the radiation beams are emitted by a single source, which rotates slowly around the patient's head. In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ...

Finally, at some medical centers such as in Boston and in California, particle accelerators built for doing research in high energy physics have been used since the 1960's for the treatment of brain tumors and arteriovenous malformations of the brain in humans. A still experimental type of radiosurgery, that utilizes a nuclear reactor for the nuclear fission of uranium, is the Neutron Capture Therapy (NCT) which was started in the United States at the nuclear reactor of the Massachusetts Institute of Technology (MIT) in the 60's, with promising results.^[1] Nowadays it is carried out as a promising advanced clinical research in several countries, due to the progress and to the results obtained in Japan by Dr. Hiroshi Hatanaka. He used NCT in more than 100 cases in the treatment of malignant tumors and of gigantic arterio-venous malformations. Nickname: City on the Hill, Beantown, The Hub (of the Universe)1, Athens of America, The Cradle of Revolution, Puritan City, Americas Walking City Location in Massachusetts, USA Counties Suffolk County Mayor Thomas M. Menino(D) Area - City 232. ... Official language(s) English Capital Sacramento Largest city Los Angeles Area Ranked 3rd - Total 158,302 sq mi (410,000 kmÂ²) - Width 250 miles (400 km) - Length 770 miles (1,240 km) - % water 4. ... A particle accelerator uses electric fields to propel charged particles to great energies. ... Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. ... Arteriovenous malformation or AVM is a congenital disorder of the veins and arteries that make up the vascular system . ... Core of a small nuclear reactor used for research. ... For the generation of electrical power by fission, see Nuclear power plant An induced nuclear fission event. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... The Massachusetts Institute of Technology (MIT) is a private, coeducational research university located in Cambridge, Massachusetts. ...

How it works

The fundamental principle of radiosurgery is that of selective ionization of the tissue to be operated upon, by means of high-energy beams of radiation. Ionization is the production of ions and free radicals which are usually deleterious to the cells. These ions and radicals, which may be formed from the water in the cell or from the biological materials can produce irreparable damage to these structures and then 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 absorbed by the treated mass of tissue is what defines the degree of biological inactivation. It usually is measured in grays, where one gray (Gy) is the absorption of one joule per kilogram of mass. A unit that attempts to take into account both 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. Ionization is the physical process of converting an atom or molecule into an ion by changing the difference between the number of protons and electrons. ... An electrostatic potential map of the nitrate ion (NO3âˆ’). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... In chemistry free radicals are uncharged atomic or molecular species with unpaired electrons or an otherwise open shell configuration. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... This article or section does not adequately cite its references or sources. ... The gray (symbol: Gy) is the SI unit of absorbed dose. ... The joule (IPA pronunciation: or ) (symbol: J) is the SI unit of energy. ... The sievert (symbol: Sv) is the SI derived unit of dose equivalent. ...

In order to perform optimal therapy, the neurosurgeon, assisted by physicists specialized in radiation therapy and often in conjunction with a radiation oncologist, chooses the best type of radiation to be used and how it will be delivered. Usually, the total dose of radiation required to kill a tumor, for example, is not delivered in a single, massive section, because this would cause undesirable effects on the patient. Instead, it is divided into several sessions of smaller duration and energy dose, in a procedure called dose fractioning. The aim of dose fractioning is to minimize the undesirable damage to healthy tissues, as healthy tissue cells are better than cancerous cells at repairing radiation induced damage between irradiations. In order to plan the radiation incidence and dosage, the physicists calculate a map portraying the lines of equal absorbed dose of radiation upon the patient's head (this is called an isodose map). Information about the tumor's location is obtained from a series of computerized tomograms, which are then fed to special planning computer software.

There are six types of irradiation currently used in radiosurgery: electromagnetical waves (gamma rays and x-rays), subatomic particles ( electrons, protons and neutrons), and carbon ions. This article is about electromagnetic radiation. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... e- redirects here. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not adequately cite its references or sources. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ...

The first type of radiation is gamma rays, which are beams of high energy photons that interact with the corona of electrons of the atoms that compose the irradiated tissue, ionizing them. Gamma radiation is used in the Gamma Knife device, where they are produced by fixed sources of radioactive cobalt. The Gamma Knife treatment is the gold standard in brain tumor treatment. Properties In chemistry and physics, an atom (Greek á¼„Ï„Î¿Î¼Î¿Ï‚ or Ã¡tomos meaning indivisible) is the smallest particle still characterizing a chemical element. ... In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... wikipedia sucks big balls For other uses, see Cobalt (disambiguation). ... In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ...

The second type of radiation, X-rays, are also high energy photons that are identical to gamma rays except for the way they are produced. Radiosurgery can be performed using a linear accelerator, the source being now a commercial medical device of universal use in radiotherapy. The Linac consists of an electron accelerator. Electrons from the accelerator can collide with a solid target to create X-radiation. In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ...

The emission head (called "gantry") 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 makes possible the computerized planning of the volume of brain tissue which is going to be irradiated. Devices with an energy of 6 MeV are the most suitable for the treatment of the brain, due to the smaller volume to be irradiated. In addition, the diameter of the energy beam leaving the emission head can be adjusted to the size of the lesion by means of interchangeable collimators (an orifice with different diameters, varying from 5 to 40 mm, in steps of 5 mm). There are also multileaf collimators, which consist of a number of metal leaflets that can be moved dynamically during treatment in order to shape the radiation beam to conform to the mass to be ablated. Linear accelerator (LINAC) used for medical radiation therapy File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Container ship Rita being loaded at Copenhagen by a portainer crane A portainer (also known as a gantry crane, container crane, container handling gantry crane, quay crane, ship-to-shore crane, STS crane or a dockside crane) is a very large crane used to load and unload container ships, and... How a lead collimator filters a stream of rays. ... Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosive processes. ...

The third type of radiation, electrons, will have very similar characteristics to that of gamma or X-rays. The depth of penetration is less than that of the above-mentioned photon sources.

The fourth type of radiation, protons, is used in Proton Beam Therapy (PBT). Protons are produced by a medical synchrotron, extracting them from proton donor materials and accelerating them in successive travels through a circular, evacuated conduit, using powerful magnets, until they reach sufficient energy (usually about 200 MeV) to enable them to approximately traverse a human body, then stop. They are then released toward the irradiation target which is region in the patient's body. In some machines, which deliver only a certain energy of protons, a custom mask made of plastic will be interposed between the initial beam and the patient, in order to adjust the beam energy for a proper amount of penetration. Because of the Bragg Peak effect, proton therapy has advantages over other the other forms of radiation, since most of the proton's energy is deposited within a limited distance, so tissue beyond this range (and so some extent also tissue inside this range) is spared from the effects of radiation. This property of protons, which has been called the "depth charge effect" 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. In recent years, however, so-called "intensity modulated" techniques have allowed for similar conformities to be attained using linear accelerator radiosurgery. Proton therapy is a kind of external beam radiotherapy where protons are directed to a tumor site. ... Synchrotrons are now mostly used for producing monochromatic high intensity X-ray beams; here, the synchrotron is the circular track, off which the beamlines branch. ... Bragg Peak When a fast charged particle moves through matter, it produces an ionisation dose by depositing energy and ionizing along its path. ...

Neutrons, the fifth type of radiation, are used in Boron neutron capture therapy (BNCT). BCNT depends on the interaction of slow neutrons with boron-10 to produce alpha particles, another type of radiation. Patients are first given an intravenous injection of a boron-10 tagged chemical that preferentially binds tumor cells. The neutrons are created either in a nuclear reactor or by colliding high-energy protons into a Lithium target. The neutrons pass through a moderator, which shapes the neutron energy spectrum suitable for BNCT treatment. Before entering the patient the neutron beam is shaped by a beam collimator. While passing through the tissue of the patient, the neutrons are slowed by collisions and become low energy thermal neutrons. The thermal neutrons undergo reaction with the boron-10 nuclei, forming an unstable boron-11 nucleus which then undergoes spontaneous decay to lithium-7 and an alpha particle. Both the alpha particle and the lithium ion produce closely spaced ionizations in the immediate vicinity of the reaction, with a range of approximately 10 micrometres, or one cell diameter. This technique is advantageous since the radiation damage occurs over a short range and thus normal tissues can be spared. Also, there are two mechanisms for tumor selectivity, since both the boron compound is made to bind to tumor cells and the neutron beam is aimed at the location of the tumor. BNCT has been developed in only in an experimental basis, and it has not entered surgical routine. Boron neutron capture therapy (BNCT) is a form of radiosurgery that utilizes a neutron beam that interacts with boron injected to a patient. ... General Name, Symbol, Number boron, B, 5 Chemical series metalloids Group, Period, Block 13, 2, p Appearance black/brown Standard atomic weight 10. ... An alpha particle is deflected by a magnetic field Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. ... This article does not cite its references or sources. ... General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/grey Atomic mass 6. ...

The selection of the proper kind of radiation and device depends on many factors including lesion type, size and location in relation to critical structures. Data suggests that similar clinical outcomes are possible with all of these methods. More important than the device used are issues regarding indications for treatment, total dose delivered, fractionation schedule and conformity of the treatment plan.

Latest generation Linacs are 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 are carried out by open or endoscopic surgery, such as for trigeminal neuralgia, etc. Trigeminal neuralgia, or Tic Douloureux, is a neuropathic disorder of the trigeminal nerve that causes episodes of intense pain in the eyes, lips, nose, scalp, forehead, and jaw. ...

Radiosurgery of brain tumors

Radiosurgery has been especially helpful for the localized, highly precise treatment of brain tumors. Due to the steep fall of the irradiation fields (isodoses) from the center of the target to be destroyed, the biological inactivation happens only on it; while the brain, and other vascular and neural structures around it, are protected. This is achieved through the high mechanical precision of the radiation source, and the assured reproducibility of the target. The precision in the positioning of the patient, in the calculation of dosages, and in the safety of the patient, are all extremely high.

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 the patient. General contraindications to radiosurgery include excessively large size of the target lesion or lesions too numerous for practical treatment.

The non-interference with the quality of life of the patient in the post-operatory period competes with the inconvenience of the latency of months until the result of the radiosurgery is accomplished. Patients with a bad general state of health and those with tumors which are unreachable by conventional means, are especially helped. The well-being or quality of life of a population is an important concern in economics and political science. ...

Outcome may not be evident for months after the treatment. Since radiosurgery does not remove the tumor, but results in a biological inactivation of the tumor, lack of growth of the lesion is normally considered to be treatment success. Radiosurgery has been used to treat many kinds of brain tumors, such as acoustic neuromas, astrocytomas, gliomas, germinomas, meningiomas, among others. Even highly fatal cancerous metastases in the brainstem can be reduced, leaving the patient neurologically intact. It has been demonstrated by the thousands of successfully treated cases, that radiosurgery can be a very safe and efficient method for the management of many difficult brain lesions, while it avoids the loss in quality of life associated to other more invasive methods. For many indications, such as acoustic neuroma, brain arteriovenous malformations and skull base tumors, radiosurgery has emerged as the treatment of choice. Acoustic neuroma (or Vestibular Schwannoma) is a benign primary intracranial tumor of the myelin forming cells called Schwann cells (Schwannoma) of the 8th cranial nerve --- also known as the acoustic nerve, (or more properly the vestibulocochlear nerve). ... Astrocytomas are primary intracranial tumors derived from astrocytes cells of the brain. ... A glioma is a type of primary central nervous system (CNS) tumor that arises from glial cells. ... Germinomas are neoplasia (commonly referred to as cancers or tumors) which most closely resemble germ line cells. ... Meningiomas are tumors arising from the outer part of the arachnoid mater in the meninges of the brain or the spinal cord. ... Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ...

Patients are being treated for lesions which only radiosurgery can solve, or because they prefer it as a first treatment, after receiving complete information of its risks and benefits as compared to the conventional surgery, when the choice is available.

In the future, advanced computer methods, such as intensity-modulated radiosurgery will be used to improve the accuracy and scope of radiosurgery. For now, the Gamma Knife is the standard for brain tumor treatment. Gamma Knife only takes one treatment session and is the most accurate surgery on the market. In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ...

See also

Clinac 2100 C100 accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... Insertion of an electrode during neurosurgery for Parkinsons disease. ... Shown above is the bone scintigraphy of a young woman. ... Stereotactic surgery or stereotaxy is a minimally-invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the body and to perform on them some action such as ablation (removal), biopsy, lesion, injection, stimulation, implantation, radiosurgery etc. ... This article does not adequately cite its references or sources. ...

Notes

References

Renato M.E. Sabbatini Renato Marcos Endrizzi Sabbatini, Brazilian biomedical and computer scientist, educator, science writer, entrepreneur and administrator, born in Campinas, State of São Paulo, Brazil, on 20 February 1947. ...

External links

Manufacturers

Categories: Articles with unsourced statements since February 2007 | All articles with unsourced statements | Neurology | Neurosurgery | Oncology | Radiobiology In medicine, Leksell Gamma Knife is a neurosurgical device used to treat brain tumors. ... Cyberknife based on Kuka 250 CyberKnife is the name of a frameless robotic radiosurgery system invented by John R. Adler, a Stanford University Neurosurgeon. ... Stereotactic radiosurgery is an accepted modality in the treatment of primary and metastatic brain tumors, benign brain tumors, and certain other neurological disorders. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Nuclear engineering is the practical application of the atomic nucleus gleaned from principles of nuclear physics and the interaction and maintenance of nuclear fission systems and components, specifically, nuclear reactors, nuclear power plants and/or nuclear weapons. ... Nuclear physics is the branch of physics concerned with the nucleus of the atom. ... For the generation of electrical power by fission, see Nuclear power plant An induced nuclear fission event. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... Radiation as used in physics, is energy in the form of waves or particles. ... Radiation hazard symbol. ... The nucleus of an atom is the very small dense region, of positive charge, in its centre consisting of nucleons (protons and neutrons). ... This diagram demonstrates the defense in depth quality of nuclear power plants. ... Nuclear chemistry is a subfield of chemistry dealing with radioactivity, nuclear processes and nuclear properties. ... Nuclear material consists of materials used in nuclear systems, such as nuclear reactors and nuclear weapons. ... Nuclear Fuel Process A graph compairing nucleon number against binding energy Nuclear fuel is any material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned to derive energy. ... Fertile material is a term used to describe nuclides which generally themselves do not undergo induced fission (fissionable by thermal neutrons) but from which fissile material is generated by neutron absorption and subsequent nuclei conversions. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass 232. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... These pie-graphs showing the relative proportions of uranium-238 (blue) and uranium-235 (red) at different levels of enrichment. ... Depleted uranium storage yard. ... General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight (244) gÂ·molâˆ’1 Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ... A nuclear power station. ... Core of CROCUS, a small nuclear reactor used for research at the EPFL in Switzerland. ... An illustration showing the various sources of nuclear waste Radioactive waste are waste types containing radioactive chemical elements that do not have a practical purpose. ... Internal view of the JET tokamak superimposed with an image of a plasma taken with a visible spectrum video camera. ... Future energy development faces great challenges due to an increasing world population, demands for higher standards of living, a need for less pollution, a need to avert global warming, and a possible end to fossil fuels (see Hubbert peak theory). ... An Inertial fusion power plant is intended to industrially produce electric power by use of inertial confinement fusion techniques. ... Pressurized water reactors (PWRs) (also VVER) are generation II nuclear power reactors that use water under high pressure as coolant and neutron moderator. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... Generation IV reactors (Gen IV) are a set of theoretical nuclear reactor designs currently being researched. ... The fast breeder or fast breeder reactor (FBR) is a fast neutron reactor designed to breed fuel by producing more fissile material than it consumes. ... A fast neutron reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons. ... Schematic diagram of a Magnox nuclear reactor showing gas flow. ... Schematic diagram of the Advanced Gas-cooled Reactor. ... The Gas-Cooled Fast Reactor (GFR) system is a Generation IV reactor concept that features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides. ... A molten salt reactor is a type of nuclear reactor where the working fluid is a molten salt. ... A Liquid metal cooled nuclear reactor is nuclear reactor where the primary coolant is a liquid molten metal. ... The Lead-cooled Fast Reactor is a Generation IV reactor that features a fast-spectrum lead or lead/bismuth eutectic liquid metal-cooled reactor with a closed fuel cycle. ... The Sodium-cooled fast reactor is a sodium cooled reactor that uses fast neutrons. ... Supercritical water reactor scheme. ... Very high temperature reactor scheme. ... Graphite Pebble for Reactor The pebble bed reactor (PBR) or pebble bed modular reactor (PBMR) is an advanced nuclear reactor design. ... The Integral Fast Reactor or Advanced Liquid-Metal Reactor is a design for a nuclear fast reactor with a specialized nuclear fuel cycle. ... Nuclear propulsion can include a wide variety of methods, the commonality of which is the use of some form of nuclear reaction as their primary power source. ... In a nuclear thermal rocket a working fluid, usually hydrogen, is heated in a high temperature nuclear reactor, and then expands through a rocket nozzle to create thrust. ... // A radioisotope thermoelectric generator (RTG) is a simple electrical generator which obtains its power from radioactive decay. ... Shown above is the bone scintigraphy of a young woman. ... Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. ... Clinac 2100 C100 accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... Proton therapy is a kind of external beam radiotherapy where protons are directed to a tumor site. ... Brachytherapy for prostate cancer is administered using seeds, small radioactive rods implanted directly into the tumour. ... Boron neutron capture therapy (BNCT) is an experimental form of radiotherapy that utilizes a neutron beam that interacts with boron injected to a patient. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter. ... A nuclear fireball lights up the night in a United States nuclear test. ... For the 1989 computer game, see Nuclear War (computer game). ... U.S. and USSR/Russian nuclear weapons stockpiles, 1945-2006. ... The first nuclear weapons, though large, cumbersome and inefficient, provided the basic design building blocks of all future weapons. ... A 23 kiloton tower shot called BADGER, fired on April 18, 1953 at the Nevada Test Site, as part of the Operation Upshot-Knothole nuclear test series. ... Preparation for an underground nuclear test at the Nevada Test Site in the 1980s. ... // Nuclear weapons delivery is the technology and systems used to place a nuclear weapon at the position of detonation, on or near its intended target. ... World map with nuclear weapons development status represented by color. ... This is a list of states with nuclear weapons. ... Main article: Nuclear testing The following is a list of nuclear test series designations, organized first by country and then by date. ...

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