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
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
Ruthenium Radioisotopes
Dose Fractionation
Administration of the total dose of radiation (RADIATION DOSAGE) in parts, at timed intervals.
Radiometry
Radiotherapy, Image-Guided
Iodine Radioisotopes
Radiotherapy, Computer-Assisted
Computer systems or programs used in accurate computations for providing radiation dosage treatment to patients.
Dose-Response Relationship, Radiation
Treatment Outcome
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
Choroid Neoplasms
Fat Necrosis
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).
Rectal Diseases
Pathological developments in the RECTUM region of the large intestine (INTESTINE, LARGE).
Magnetic Resonance Imaging, Interventional
Radiotherapy, Conformal
Organs at Risk
Neoplasm Recurrence, Local
Histiocytoma
A neoplasm containing HISTIOCYTES. Important forms include BENIGN FIBROUS HISTIOCYTOMA; and MALIGNANT FIBROUS HISTIOCYTOMA.
Urination Disorders
Strontium Radioisotopes
Radioisotopes
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.
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
Radiation Protection
Prostate-Specific Antigen
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.
Coronary Restenosis
Colon, Sigmoid
A segment of the COLON between the RECTUM and the descending colon.
Neoplasm Staging
Follow-Up Studies
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)