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Electron Therapy
Electron therapy or electron beam therapy (EBT) is a kind of external beam radiotherapy where electrons are directed to a tumor site for medical treatment of cancer. Equipment Electron beam therapy is performed using a medical linear accelerator. The same device can also be used to produce high energy photon beams. When electrons are required, the x-ray target is retracted out of the beam and the electron beam is collimated with a piece of apparatus known as an applicator or an additional collimating insert, constructed from a low melting point alloy. Properties Electron beams have a finite range, after which dose falls off rapidly. Therefore, they spare deeper healthy tissue. The depth of the treatment is selected by the appropriate energy. Unlike photon beams there is no surface sparing effect, so electron therapy is used when the target extends to the patient's skin. Indications Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Beam Radiotherapy
External beam radiotherapy (EBRT) is the most common form of radiotherapy (radiation therapy). The patient sits or lies on a couch and an external source of ionizing radiation is pointed at a particular part of the body. In contrast to brachytherapy (sealed source radiotherapy) and unsealed source radiotherapy, in which the radiation source is inside the body, external beam radiotherapy directs the radiation at the tumour from outside the body. Orthovoltage ("superficial") X-rays are used for treating skin cancer and superficial structures. Megavoltage X-rays are used to treat deep-seated tumours (e.g. bladder, bowel, prostate, lung, or brain), whereas megavoltage electron beams are typically used to treat superficial lesions extending to a depth of approximately 5 cm (increasing beam energy corresponds to greater penetration). X-rays and electron beams are by far the most widely used sources for external beam radiotherapy. A small number of centers operate experimental and pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastectomy
Mastectomy is the medical term for the surgical removal of one or both breasts, partially or completely. A mastectomy is usually carried out to treat breast cancer. In some cases, women believed to be at high risk of breast cancer have the operation as a preventive measure. Alternatively, some women can choose to have a wide local excision, also known as a lumpectomy, an operation in which a small volume of breast tissue containing the tumor and a surrounding margin of healthy tissue is removed to conserve the breast. Both mastectomy and lumpectomy are referred to as "local therapies" for breast cancer, targeting the area of the tumor, as opposed to systemic therapies, such as chemotherapy, hormonal therapy, or immunotherapy. The decision to perform a mastectomy is based on various factors, including breast size, the number of lesions, biologic aggressiveness of a breast cancer, the availability of adjuvant radiation, and the willingness of the patient to accept higher rates of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Beams In Medical Applications
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 Broglie wavel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton Therapy
In medicine, proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer. The chief advantage of proton therapy over other types of external beam radiotherapy is that the dose of protons is deposited over a narrow range of depth; hence in minimal entry, exit, or scattered radiation dose to healthy nearby tissues. When evaluating whether to treat a tumor with photon or proton therapy, physicians may choose proton therapy if it is important to deliver a higher radiation dose to targeted tissues while significantly decreasing radiation to nearby organs at risk. The American Society for Radiation Oncology Model Policy for Proton Beam therapy says proton therapy is considered reasonable if sparing the surrounding normal tissue "cannot be adequately achieved with photon-based radiotherapy" and can benefit the patient. Like photon radiation therapy, proton therapy is often used in conjuncti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Beam Radiotherapy
External beam radiotherapy (EBRT) is the most common form of radiotherapy (radiation therapy). The patient sits or lies on a couch and an external source of ionizing radiation is pointed at a particular part of the body. In contrast to brachytherapy (sealed source radiotherapy) and unsealed source radiotherapy, in which the radiation source is inside the body, external beam radiotherapy directs the radiation at the tumour from outside the body. Orthovoltage ("superficial") X-rays are used for treating skin cancer and superficial structures. Megavoltage X-rays are used to treat deep-seated tumours (e.g. bladder, bowel, prostate, lung, or brain), whereas megavoltage electron beams are typically used to treat superficial lesions extending to a depth of approximately 5 cm (increasing beam energy corresponds to greater penetration). X-rays and electron beams are by far the most widely used sources for external beam radiotherapy. A small number of centers operate experimental and pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IOERT
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] |
Lumpectomy
Lumpectomy (sometimes known as a tylectomy, partial mastectomy, breast segmental resection or breast wide local excision) is a surgical removal of a discrete portion or "lump" of breast tissue, usually in the treatment of a malignant tumor or breast cancer. It is considered a viable breast conservation therapy, as the amount of tissue removed is limited compared to a full-breast mastectomy, and thus may have physical and emotional advantages over more disfiguring treatment. Sometimes a lumpectomy may be used to either confirm or rule out that cancer has actually been detected. A lumpectomy is usually recommended to patients whose cancer has been detected early and who do not have enlarged tumors. Although a lumpectomy is used to allow for most of the breast to remain intact, the procedure may result in adverse affects that can include sensitivity and result in scar tissue, pain, and possible disfiguration of the breast if the lump taken out is significant. According to National Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphoma
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph nodes, fever, drenching sweats, unintended weight loss, itching, and constantly feeling tired. The enlarged lymph nodes are usually painless. The sweats are most common at night. Many subtypes of lymphomas are known. The two main categories of lymphomas are the non-Hodgkin lymphoma (NHL) (90% of cases) and Hodgkin lymphoma (HL) (10%). The World Health Organization (WHO) includes two other categories as types of lymphoma – multiple myeloma and immunoproliferative diseases. Lymphomas and leukemias are a part of the broader group of tumors of the hematopoietic and lymphoid tissues. Risk factors for Hodgkin lymphoma include infection with Epstein–Barr virus and a history of the disease in the family. Risk factors for common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrons
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 Broglie wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanoma
Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In women, they most commonly occur on the legs, while in men, they most commonly occur on the back. About 25% of melanomas develop from moles. Changes in a mole that can indicate melanoma include an increase in size, irregular edges, change in color, itchiness, or skin breakdown. The primary cause of melanoma is ultraviolet light (UV) exposure in those with low levels of the skin pigment melanin. The UV light may be from the sun or other sources, such as tanning devices. Those with many moles, a history of affected family members, and poor immune function are at greater risk. A number of rare genetic conditions, such as xeroderma pigmentosum, also increase the risk. Diagnosis is by biopsy and analysis of any skin lesion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycosis Fungoides
Mycosis fungoides, also known as Alibert-Bazin syndrome or granuloma fungoides, is the most common form of cutaneous T-cell lymphoma. It generally affects the skin, but may progress internally over time. Symptoms include rash, tumors, skin lesions, and itchy skin. While the cause remains unclear, most cases are not hereditary. Most cases are in people over 20 years of age, and it is more common in men than women. Treatment options include sunlight exposure, ultraviolet light, topical corticosteroids, chemotherapy, and radiotherapy. Signs and symptoms The symptoms of mycosis fungoides are categorized into three clinical stages: the patch stage, the plaque stage, and the tumour stage. The patch stage is defined by flat, reddish patches of varying sizes that may have a wrinkled appearance. They can also look yellowish in people with darker skin. The plaque stage follows the patch stage of mycosis fungoides. It is characterized by the presence of raised lesions that appear reddis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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