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Intraoperative Electron Radiation Therapy
Intraoperative electron radiation therapy is the application of electron radiation directly to the residual tumor or tumor bed during cancer surgery. Electron beams are useful for intraoperative radiation treatment because, depending on the electron energy, the dose falls off rapidly behind the target site, therefore sparing underlying healthy tissue. IOERT has been called "precision radiotherapy," because the physician has direct visualization of the tumor and can exclude normal tissue from the field while protecting critical structures within the field and underlying the target volume. One advantage of IOERT is that it can be given at the time of surgery when microscopic residual tumor cells are most vulnerable to destruction. Also, IOERT is often used in combination with external beam radiotherapy (EBR) because it results in less integral doses and shorter treatment times. Medical uses IOERT has a long history of clinical applications, with promising results, in the mana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Brog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray (unit)
The gray (symbol: Gy) is the unit of ionizing radiation dose in the International System of Units (SI), defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose that measures the energy deposited by ionizing radiation in a unit mass of matter being irradiated, and is used for measuring the delivered dose in radiotherapy, food irradiation and radiation sterilization. It is important in predicting likely acute health effects, such as acute radiation syndrome and is used to calculate equivalent dose using the sievert, which is a measure of the stochastic health effect on the human body. The gray is also used in radiation metrology as a unit of the radiation quantity kerma; defined as the sum of the initial kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter per unit mass. The gray is an important unit in ionising radiation measurem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betatron
A betatron is a type of cyclic particle accelerator. It is essentially a transformer with a torus-shaped vacuum tube as its secondary coil. An alternating current in the primary coils accelerates electrons in the vacuum around a circular path. The betatron was the first machine capable of producing electron beams at energies higher than could be achieved with a simple electron gun, and the first circular accelerator in which particles orbited at a constant radius. The concept of the betatron had been proposed as early as 1922 by Joseph Slepian. Through the 1920s and 30s a number of theoretical problems related to the device were considered by scientists including Rolf Wideroe, Ernest Walton, and Max Steenbeck. The first working betatron was constructed by Donald Kerst at the University of Illinois Urbana-Champaign in 1940. History After the discovery in the 1800s of Faraday's law of induction, which showed that an electromotive force could be generated by a changing mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyoto University
, mottoeng = Freedom of academic culture , established = , type = Public (National) , endowment = ¥ 316 billion (2.4 billion USD) , faculty = 3,480 (Teaching Staff) , administrative_staff = 3,978 (Total Staff) , students = 22,615 , president = Nagahiro Minato , city = Kyoto , state = Kyoto , country = Japan , coor = , undergrad = 13,038 , postgrad = 9,308 , campus = Urban,, , colors = Dark blue , nickname = Kyodai , mascot = None , free_label = Athletics , free = 48 varsity teams , affiliations = Kansai Big Six, ASAIHL , logo = , website www.kyoto-u.ac.jp , or , is a public research university located in Kyoto, Japan. Founded in 1897, it is one of the former Imperial Universities and the second oldest university in Japan. KyotoU is consistently ranked amongst the top two in Japan, the top ten in Asia, and the world's top fifty institutions of higher education. Founded upon the principles of its motto, “ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megavoltage
Megavoltage X-rays are produced by linear accelerators ("linacs") operating at voltages in excess of 1000 kV (1 MV) range, and therefore have an energy in the MeV range. The voltage in this case refers to the voltage used to accelerate electrons in the linear accelerator and indicates the maximum possible energy of the photons which are subsequently produced. They are used in medicine in external beam radiotherapy to treat neoplasms, cancer and tumors. Beams with the voltage range of 4-25 MV are used to treat deeply buried cancers because radiation oncologists find that they penetrate well to deep sites within the body. Lower energy x-rays, called orthovoltage X-rays, are used to treat cancers closer to the surface. Megavoltage x-rays are preferred for treatment of deep lying tumours as they are attenuated less than lower energy photons, and will penetrate further, with a lower skin dose. Megavoltage x-rays also have lower relative biological effectiveness than o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IORT
Intraoperative radiation therapy (IORT) is radiation therapy that is administered during surgery directly in the operating room (hence ''intraoperative''). Usually therapeutic levels of radiation are delivered to the tumor bed while the area is exposed during surgery. IORT is typically a component in the multidisciplinary treatment of locally advanced and recurrent cancer, in combination with external beam radiation, surgery, and chemotherapy. As a growing trend in recent years, IORT can also be used in earlier stage cancers such as prostate and breast cancer. Medical uses IORT was found to be useful and feasible in the multidisciplinary management of many solid tumors but further studies are needed to determine the benefit more precisely. Single-institution experiences have suggested a role of IORT e.g. in brain tumors and cerebral metastases, locally advanced and recurrent rectal cancer, skin cancer, retroperitoneal sarcoma, pancreatic cancer, and selected gynaecologic and gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-rays
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz ( to ) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . Spellings of ''X-ray(s)'' in English include the variants ''x-ray(s)'', ''xray(s)'', and ''X ray(s)''. The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraoperative Radiation Therapy
Intraoperative radiation therapy (IORT) is radiation therapy that is administered during surgery directly in the operating room (hence ''intraoperative''). Usually therapeutic levels of radiation are delivered to the tumor bed while the area is exposed during surgery. IORT is typically a component in the multidisciplinary treatment of locally advanced and recurrent cancer, in combination with external beam radiation, surgery, and chemotherapy. As a growing trend in recent years, IORT can also be used in earlier stage cancers such as prostate and breast cancer. Medical uses IORT was found to be useful and feasible in the multidisciplinary management of many solid tumors but further studies are needed to determine the benefit more precisely. Single-institution experiences have suggested a role of IORT e.g. in brain tumors and cerebral metastases, locally advanced and recurrent rectal cancer, skin cancer, retroperitoneal sarcoma, pancreatic cancer, and selected gynaecologic and geni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limb-sparing Techniques
Limb-sparing techniques, also known as limb-saving or limb-salvage techniques, are performed in order to preserve the look and function of limbs. Limb-sparing techniques are used to preserve limbs affected by trauma, arthritis, cancers such as high-grade bone sarcomas, and vascular conditions such as diabetic foot ulcers. As the techniques for chemotherapy, radiation, and diagnostic modalities improve, there has been a trend toward limb-sparing procedures to avoid amputation, which has been associated with a lower 5-year survival rate and cost-effectiveness compared to limb salvage in the long-run. There are many different types of limb-sparing techniques, including arthrodesis, arthroplasty, endoprosthetic reconstruction, various types of implants, rotationplasty, osseointegration limb replacement, fasciotomy, and revascularization. Arthrodesis Arthrodesis is the surgical immobilization of bones within a joint to promote fusion of the joint. Arthrodesis is performed most commonly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resection (surgery)
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pathological condition such as a disease or injury, to help improve bodily function, appearance, or to repair unwanted ruptured areas. The act of performing surgery may be called a surgical procedure, operation, or simply "surgery". In this context, the verb "operate" means to perform surgery. The adjective surgical means pertaining to surgery; e.g. surgical instruments or surgical nurse. The person or subject on which the surgery is performed can be a person or an animal. A surgeon is a person who practices surgery and a surgeon's assistant is a person who practices surgical assistance. A surgical team is made up of the surgeon, the surgeon's assistant, an anaesthetist, a circulating nurse and a surgical technologist. Surgery usually spans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcomas
A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal (connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sarcomas can arise in any of these types of tissues. As a result, there are many subtypes of sarcoma, which are classified based on the specific tissue and type of cell from which the tumor originates. Sarcomas are ''primary'' connective tissue tumors, meaning that they arise in connective tissues. This is in contrast to ''secondary'' (or "metastatic") connective tissue tumors, which occur when a cancer from elsewhere in the body (such as the lungs, breast tissue or prostate) spreads to the connective tissue. The word ''sarcoma'' is derived from the Greek σάρκωμα ''sarkōma'' "fleshy excrescence or substance", itself from σάρξ ''sarx'' meaning "flesh". Classification Sarcomas are typically divided into two major groups: bone sarco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Division
Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell division: a vegetative division ( mitosis), producing daughter cells genetically identical to the parent cell, and a cell division that produces haploid gametes for sexual reproduction (meiosis), reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells. In cell biology, mitosis ( /maɪˈtoʊsɪs/) is a part of the cell cycle, in which, replicated chromosomes are separated into two new nuclei. Cell division gives rise to genetically identical cells in which the total number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of interphase (during which the DNA replication occurs) and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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