Flashcards in Vocab List Deck (37)
Abnormal growth of tissue resulting from uncontrolled progressive multiplication of cells that serves no function.
The depth at which electronic equilibrium occurs for photon beams. Depth of maximum absorbed dose and ionization photons in a treatment field.
Dose delivered at the depth of D-max through a single treatment field.
Unit of output measure used for linear accelerations.
1 mu= 1cGy
Point of intersection of 3 axis of rotation of treatment unit.
Central portion of the beam, emanating from the target. Does not diverge.
SSD set up
Distance from source to patient's skin
SAD set up
Distance from source to axis of rotation of the treatment unit.
Collimator field size
Open field size, projected at a reference distance, usually isocenter (100cm)
Blocked (Effective) Field Size
Equivalent rectangle field dimension of the open treatment area within the collimated field.
Small pocket of electromagnetic energy.
Negatively charged subatomic energy that can be accelerated by a variety of machines or can be admitted from decaying isotopes.
Tool that modifies the asides distribution of a beam to correct for tissue in homogeneities.
Correct for tissue and homogeneities.
Used to form (shape) the treatment field.
Distinct part of a linear accelerator that allows treatment field shaping through the use of motorized leaves in the head of the machine.
Electron Applicator (Cone)
Extended metal structure ised to restrict the useful beam to the required size.
Tissue equivalent material placed on the skin to increase skin dose and even out irregular contours on the patient.
Allows part of the beam to pass through while reflecting the other part of the beam.
Immobilization devices, made from styrofoam.
Thermoplastic immobilization device.
Used to helo immobilize and help position the tongue.
Used to set up the patient correctly.
treat the patient with one field
Parallel Opposed Field
Paid of fields directed along the same axis, form opposite sides.
Two oblique fields, similar to a breast bridge.
(distance from midline to lateral portion)
Rotation/ Arc Therapy
Isocentric technique when beam moves continuously about the patient.
Uses radioactive material to deliver dose administered directly into the tumor.
Shows distribution of absorbed dose in points of equal dose.
Critical Organ Dose
Organs that limit the dose or the dose that can be tolerated by critical sructures.
Organs at Risk
The distance between the borders of two adjacent fields usually measured on the patient's skin. Used to measure and verify the depth of two adjacent fields.
Image Guided Radiation Therapy (IGRT)
The use of imaging to compare the position of external set up marks and internal anatomy to the treatment plan.
Intensity Modulated Radiation Therapy (IMRT)
Delivers nonuniform exposure across the beam's eye view using a variety of techniques and equipment.
Volumetric Modulated Arc Therapy (VMAT)
A type of specialized IMRT where VMAT delivers radiation by rotating machine through 1 or more arcs while radiation is continuously delivered.
Type of rad therapy in which the radiation is delivered slice by slice.