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Total Body Irradiation
Total body irradiation (TBI) is a form of radiotherapy used primarily as part of the preparative regimen for haematopoietic stem cell (or bone marrow) transplantation. As the name implies, TBI involves irradiation of the entire body, though in modern practice the lungs are often partially shielded to lower the risk of radiation-induced lung injury. Total body irradiation in the setting of bone marrow transplantation serves to destroy or suppress the recipient's immune system, preventing immunologic rejection of transplanted donor bone marrow or blood stem cells. Additionally, high doses of total body irradiation can eradicate residual cancer cells in the transplant recipient, increasing the likelihood that the transplant will be successful. Dosage Doses of total body irradiation used in bone marrow transplantation typically range from 10 to >12 Gy. For reference, an unfractionated (i.e. single exposure) dose of 4.5 Gy is fatal in 50% of exposed individuals without ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiotherapy
Radiation therapy or radiotherapy (RT, RTx, or XRT) is a treatment using ionizing radiation, generally provided as part of cancer therapy to either kill or control the growth of malignant cells. It is normally delivered by a linear particle accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body, and have not spread to other parts. 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. Ionizin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose Fractionation
Dose fractionation effects are utilised in the treatment of cancer with radiation therapy. When the total dose of radiation is divided into several, smaller doses over a period of several days, there are fewer toxic effects on healthy cells. This maximizes the effect of radiation on cancer and minimizes the negative side effects. A typical fractionation scheme divides the dose into 30 units delivered every weekday over six weeks. Background Experiments in radiation biology have found that as the absorbed dose of radiation increases, the number of cells which survive decreases. They have also found that if the radiation is ''fractionated'' into smaller doses, with one or more rest periods in between, fewer cells die. This is because of self-repair mechanisms which repair the damage to DNA and other biomolecules such as proteins. These mechanisms can be over expressed in cancer cells, so caution should be used in using results for a cancer cell line to make predictions for heal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oocyte Cryopreservation
Oocyte cryopreservation (commonly referred to as OC or egg freezing) is a form of assisted reproductive technology (ART) used to preserve human eggs (oocytes). The technique is often used to delay pregnancy. When pregnancy is desired, the eggs can be thawed, fertilized, and transferred to the uterus as embryos. The procedure's success rate varies depending on factors such as the individual's age (with higher odds of success in younger individuals), overall health, and genetic factors. The first human birth of oocyte cryopreservation was reported in 1986. According to a review, which included 936 live births between 1986 and 2008 in the United States obtained from 58 cryopreservation studies, the incidence of major structural congenital anomalies was 1.3%. There were no significant differences compared to naturally-conceived infants. Studies have been undertaken by the National Institute For Health and Care Excellence, determining that although there is insufficient data for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryo Cryopreservation
Embryos may be preserved through cryopreservation, generally at an embryogenesis stage corresponding to pre-implantation, that is, from fertilisation to the blastocyst stage. Indications Embryo cryopreservation is useful for leftover embryos after a cycle of in vitro fertilisation, as patients who fail to conceive may become pregnant using such embryos without having to go through a full IVF cycle. Or, if pregnancy occurred, they could return later for another pregnancy. Spare oocytes or embryos resulting from fertility treatments may be used for oocyte donation or embryo donation to another woman or couple, and embryos may be created, frozen and stored specifically for transfer and donation by using donor eggs and sperm. Method Embryo cryopreservation is generally performed as a component of in vitro fertilization (which generally also includes ovarian hyperstimulation, egg retrieval and embryo transfer). The ovarian hyperstimulation is preferably done by using a GnRH agonist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryopreservation Of Ovarian Tissue
Ovarian tissue cryopreservation is cryopreservation of tissue of the ovary of a female. Indications Cryopreservation of ovarian tissue is of interest to women who want fertility preservation beyond the natural limit, or whose reproductive potential is threatened by cancer therapy, for example in hematologic malignancies or breast cancer. It can be performed on prepubertal girls at risk for premature ovarian failure, and this procedure is as feasible and safe as comparable operative procedures in children. Procedure The procedure is to take a part of the ovary and carry out slow freezing before storing it in liquid nitrogen whilst therapy is undertaken. Tissue can then be thawed and implanted near the fallopian, either orthotopic (on the natural location) or heterotopic (on the abdominal wall), where it starts to produce new eggs, allowing normal conception to take place. A study of 60 procedures concluded that ovarian tissue harvesting appears to be safe. A study has also conclud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertility Preservation
Fertility preservation is the effort to help cancer patients retain their fertility, or ability to procreate. Research into how cancer, ageing and other health conditions effect reproductive health and preservation options are growing. Specifically sparked in part by the increase in the survival rate of cancer patients. Indications Fertility preservation procedures are indicated when it is predicted that there will be exposure to a cause of infertility, mainly cancer treatment but also ageing, sex reassignment surgery for those who identify as trans and conditions like Polycystic Ovary Syndrome (PCOS) or Primary Ovarian Insufficiency (POI). Chemotherapy and radiotherapy Chemotherapy and radiation treatments for cancer and autoimmunity conditions like Lupus and Multiple Sclerosis have the ability to affect reproductive health. The regimens that threaten ovarian and testicular function are mainly radiation therapy to the pelvic area and some types of chemotherapy. Chemotherapi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinical Trial
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, pharmaceutical drug, drugs, medical nutrition therapy, dietary choices, dietary supplements, and medical devices) and known interventions that warrant further study and comparison. Clinical trials generate data on dosage, safety and efficacy. They are conducted only after they have received institutional review board, health authority/ethics committee approval in the country where approval of the therapy is sought. These authorities are responsible for vetting the risk/benefit ratio of the trial—their approval does not mean the therapy is 'safe' or effective, only that the trial may be conducted. Depending on product type and development stage, investigators initially enroll volunteers or patients into small Pilot experiment, pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treatment Modality
A therapy or medical treatment is the attempted remediation of a health problem, usually following a medical diagnosis. Both words, ''treatment'' and ''therapy'', are often abbreviated tx, Tx, or Tx. As a rule, each therapy has indications and contraindications. There are many different types of therapy. Not all therapies are effective. Many therapies can produce unwanted adverse effects. ''Treatment'' and ''therapy'' are often synonymous, especially in the usage of health professionals. However, in the context of mental health, the term ''therapy'' may refer specifically to psychotherapy. Semantic field The words ''care'', ''therapy'', ''treatment'', and ''intervention'' overlap in a semantic field, and thus they can be synonymous depending on context. Moving rightward through that order, the connotative level of holism decreases and the level of specificity (to concrete instances) increases. Thus, in health-care contexts (where its senses are always noncount), th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematopoietic Stem Cell Transplantation
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce additional normal blood cells. HSCT may be autologous (the patient's own stem cells are used), syngeneic (stem cells from an identical twin), or allogeneic (stem cells from a donor). It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma, leukemia, some types of lymphoma and immune deficiencies. In these cases, the recipient's immune system is usually suppressed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT. HSCT remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of Homeland Security
The United States Department of Homeland Security (DHS) is the U.S. United States federal executive departments, federal executive department responsible for public security, roughly comparable to the Interior minister, interior, Home Secretary, home, or Ministry of Public Security, public security ministries in other countries. Its missions involve anti-terrorism, border security, civil defense, Immigration to the United States, immigration and customs, border security, border control, cyber security, cybersecurity, Airport security, transportation security, Maritime security (USCG), maritime security and Air-sea rescue, sea rescue, and the mitigation of Weapon of mass destruction, weapons of mass destruction. It began operations on March 1, 2003, after being formed as a result of the Homeland Security Act of 2002, enacted in response to the September 11 attacks. With more than 240,000 employees, DHS is the third-largest Cabinet of the United States, Cabinet department, after t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematopoietic Stem Cell Transplantation
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce additional normal blood cells. HSCT may be autologous (the patient's own stem cells are used), syngeneic (stem cells from an identical twin), or allogeneic (stem cells from a donor). It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma, leukemia, some types of lymphoma and immune deficiencies. In these cases, the recipient's immune system is usually suppressed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT. HSCT remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
