Brachytherapy: A collective term for interstitial, intracavity, and surface radiotherapy. It uses small sealed or partly-sealed sources that may be placed on or near the body surface or within a natural body cavity or implanted directly into the tissues.Iridium Radioisotopes: Unstable isotopes of iridium that decay or disintegrate emitting radiation. Ir atoms with atomic weights 182-190, 192, and 194-198 are radioactive iridium isotopes.Radiotherapy Dosage: The total amount of radiation absorbed by tissues as a result of radiotherapy.Radiotherapy Planning, Computer-Assisted: Computer-assisted mathematical calculations of beam angles, intensities of radiation, and duration of irradiation in radiotherapy.Radiation Injuries: Harmful effects of non-experimental exposure to ionizing or non-ionizing radiation in VERTEBRATES.Ruthenium Radioisotopes: Unstable isotopes of ruthenium that decay or disintegrate emitting radiation. Ru atoms with atomic weights 93-95, 97, 103, and 105-108 are radioactive ruthenium isotopes.Dose Fractionation: Administration of the total dose of radiation (RADIATION DOSAGE) in parts, at timed intervals.Prostatic Neoplasms: Tumors or cancer of the PROSTATE.Radiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Radiotherapy, Image-Guided: The use of pre-treatment imaging modalities to position the patient, delineate the target, and align the beam of radiation to achieve optimal accuracy and reduce radiation damage to surrounding non-target tissues.Vaginal Neoplasms: Tumors or cancer of the VAGINA.Uterine Cervical Neoplasms: Tumors or cancer of the UTERINE CERVIX.Beta Particles: High energy POSITRONS or ELECTRONS ejected from a disintegrating atomic nucleus.Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Radiotherapy, Computer-Assisted: Computer systems or programs used in accurate computations for providing radiation dosage treatment to patients.Dose-Response Relationship, Radiation: The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Ytterbium: Ytterbium. An element of the rare earth family of metals. It has the atomic symbol Yb, atomic number 70, and atomic weight 173. Ytterbium has been used in lasers and as a portable x-ray source.Combined Modality Therapy: The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.Radiotherapy: The use of IONIZING RADIATION to treat malignant NEOPLASMS and some benign conditions.Tongue Neoplasms: Tumors or cancer of the TONGUE.Choroid Neoplasms: Tumors of the choroid; most common intraocular tumors are malignant melanomas of the choroid. These usually occur after puberty and increase in incidence with advancing age. Most malignant melanomas of the uveal tract develop from benign melanomas (nevi).Fat Necrosis: A condition in which the death of adipose tissue results in neutral fats being split into fatty acids and glycerol.Radiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Rectum: The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.Rectal Diseases: Pathological developments in the RECTUM region of the large intestine (INTESTINE, LARGE).Magnetic Resonance Imaging, Interventional: Minimally invasive procedures guided with the aid of magnetic resonance imaging to visualize tissue structures.Urinary Retention: Inability to empty the URINARY BLADDER with voiding (URINATION).Radiotherapy, Conformal: Radiotherapy where there is improved dose homogeneity within the tumor and reduced dosage to uninvolved structures. The precise shaping of dose distribution is achieved via the use of computer-controlled multileaf collimators.Organs at Risk: Organs which might be damaged during exposure to a toxin or to some form of therapy. It most frequently refers to healthy organs located in the radiation field during radiation therapy.Neoplasm Recurrence, Local: The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.Histiocytoma: A neoplasm containing HISTIOCYTES. Important forms include BENIGN FIBROUS HISTIOCYTOMA; and MALIGNANT FIBROUS HISTIOCYTOMA.Uveal Neoplasms: Tumors or cancer of the UVEA.Urination Disorders: Abnormalities in the process of URINE voiding, including bladder control, frequency of URINATION, as well as the volume and composition of URINE.Strontium Radioisotopes: Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Prosthesis Implantation: Surgical insertion of a prosthesis.Radioisotope Teletherapy: A type of high-energy radiotherapy using a beam of gamma-radiation produced by a radioisotope source encapsulated within a teletherapy unit.Radiotherapy, High-Energy: Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.Glossectomy: Partial or total surgical excision of the tongue. (Dorland, 28th ed)Radiation Oncology: A subspecialty of medical oncology and radiology concerned with the radiotherapy of cancer.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Radiation ProtectionProstate-Specific Antigen: A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.Radiotherapy, Adjuvant: Radiotherapy given to augment some other form of treatment such as surgery or chemotherapy. Adjuvant radiotherapy is commonly used in the therapy of cancer and can be administered before or after the primary treatment.Androgen Antagonists: Compounds which inhibit or antagonize the biosynthesis or actions of androgens.Coronary Restenosis: Recurrent narrowing or constriction of a coronary artery following surgical procedures performed to alleviate a prior obstruction.Genital Neoplasms, Female: Tumor or cancer of the female reproductive tract (GENITALIA, FEMALE).Colon, Sigmoid: A segment of the COLON between the RECTUM and the descending colon.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Rhenium: Rhenium. A metal, atomic number 75, atomic weight 186.2, symbol Re. (Dorland, 28th ed)Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)Mastectomy, Segmental: Removal of only enough breast tissue to ensure that the margins of the resected surgical specimen are free of tumor.