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Radiation Treatment Planning
In radiotherapy, radiation treatment planning (RTP) is the process in which a team consisting of radiation oncologists, radiation therapist, medical physicists and medical dosimetrists plan the appropriate external beam radiotherapy or internal brachytherapy treatment technique for a patient with cancer. History In the early days of radiotherapy planning was performed on 2D x-ray images, often by hand and with manual calculations. Computerised treatment planning systems began to be used in the 1970s to improve the accuracy and speed of dose calculations. By the 1990s CT scans, more powerful computers, improved dose calculation algorithms and Multileaf collimators (MLCs) lead to 3D conformal planning (3DCRT), categorised as a Level 2 technique by the European Dynarad consortium. 3DCRT uses MLCs to shape the radiotherapy beam to closely match the shape of a target tumour, reducing the dose to healthy surrounding tissue. Level 3 techniques such as IMRT and VMAT utilise inverse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doctor Review Brain Images
Doctor or The Doctor may refer to: Personal titles * Doctor (title), the holder of an accredited academic degree * A medical practitioner, including: ** Physician ** Surgeon ** Dentist ** Veterinary physician ** Optometrist *Other roles ** Doctor of the Church, a title given to those with great contribution to Christian theology or doctrine ** Doctor of Philosophy ** Doctor of Pharmacy ** Doctor of Nursing Practice People * The Doctor (nickname), people with nickname or stage name of "Doctor" or "The Doctor" * Sean Doctor (born 1966), American football player * Doctor Willard Bliss (1825–1889), American physician * Doctor Greenwood (1860–1951), English footballer * List of physicians Arts, entertainment, and media Characters * Doctor, a character in 1998 American comedy movie ''My Giant#Cast, My Giant'' * Doctor (Black Cat), Doctor (''Black Cat'') * Doctor (Hellsing), Doctor (''Hellsing'') * Cave Story#Characters, The Doctor (''Cave Story''), also known as Fuyuhiko ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intensity Modulated Radiation Therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachytherapy
Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. ''Brachy'' is Greek for short. Brachytherapy is commonly used as an effective treatment for cervical, prostate, breast, esophageal and skin cancer and can also be used to treat tumours in many other body sites. Treatment results have demonstrated that the cancer-cure rates of brachytherapy are either comparable to surgery and external beam radiotherapy (EBRT) or are improved when used in combination with these techniques. Brachytherapy can be used alone or in combination with other therapies such as surgery, EBRT and chemotherapy. Brachytherapy contrasts with unsealed source radiotherapy, in which a therapeutic radionuclide (radioisotope) is injected into the body to chemically localize to the tissue requiring destruction. It also contrasts to External Beam Radiation Therapy (EBRT), in which high-energy x-rays (or occasionally gamma-rays fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Problem
An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, source reconstruction in acoustics, or calculating the density of the Earth from measurements of its gravity field. It is called an inverse problem because it starts with the effects and then calculates the causes. It is the inverse of a forward problem, which starts with the causes and then calculates the effects. Inverse problems are some of the most important mathematical problems in science and mathematics because they tell us about parameters that we cannot directly observe. They have wide application in system identification, optics, radar, acoustics, communication theory, signal processing, medical imaging, computer vision, geophysics, oceanography, astronomy, remote sensing, natural language processing, machine learning, nondestructive testing, slope stability analysis and many other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monte Carlo Method
Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deterministic in principle. They are often used in physical and mathematical problems and are most useful when it is difficult or impossible to use other approaches. Monte Carlo methods are mainly used in three problem classes: optimization, numerical integration, and generating draws from a probability distribution. In physics-related problems, Monte Carlo methods are useful for simulating systems with many coupled degrees of freedom, such as fluids, disordered materials, strongly coupled solids, and cellular structures (see cellular Potts model, interacting particle systems, McKean–Vlasov processes, kinetic models of gases). Other examples include modeling phenomena with significant uncertainty in inputs such as the calculation of ris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pencil Beam
In optics, a pencil or pencil of rays is a geometric construct used to describe a beam or portion of a beam of electromagnetic radiation or charged particles, typically in the form of a narrow beam (conical or cylindrical). Antennas which strongly bundle in azimuth and elevation are often described as "pencil-beam" antennas. For example, a phased array antenna can send out a beam that is extremely thin. Such antennas are used for tracking radar, and the process is known as beamforming. In optics, the focusing action of a lens is often described in terms of pencils of rays. In addition to conical and cylindrical pencils, optics deals with astigmatic pencils as well. In electron optics, scanning electron microscopes use narrow pencil beams to achieve a deep depth of field. Ionizing radiation used in radiation therapy, whether photons or charged particles, such as proton therapy and electron therapy machines, is sometimes delivered through the use of pencil beam scanning. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wedge (radiotherapy)
A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width..''McGraw-Hill Concise Encyclopedia of Science & Technology'', Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, p. 2041. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle. The force is applied on a flat, broad surface. This energy is transported to the pointy, sharp end of the wedge, hence the force is transported. The wedge simply transports energy in the form of friction and collects it to the pointy end, consequently breaking the item. History Wedges have ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ (anatomy)
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system. An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumour
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose-volume Histogram
A dose-volume histogram (DVH) is a histogram relating radiation dose to tissue volume in radiation therapy planning. DVHs are most commonly used as a plan evaluation tool and to compare doses from different plans or to structures. DVHs were introduced by Michael Goitein (who introduced radiation therapy concepts such as the "beam's-eye-view," "digitally reconstructed radiograph," and uncertainty/error in planning and positioning, among others) and Verhey in 1979. DVH summarizes 3D dose distributions in a graphical 2D format. In modern radiation therapy, 3D dose distributions are typically created in a computerized treatment planning system (TPS) based on a 3D reconstruction of a CT scan. The "volume" referred to in DVH analysis is a target of radiation treatment, a healthy organ nearby a target, or an arbitrary structure. Types DVHs can be visualized in either of two ways: differential DVHs or cumulative DVHs. A DVH is created by first determining the size of the dose bins of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
