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Flashcards in Vocab List Deck (37)
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1

Tumor

Abnormal growth of tissue resulting from uncontrolled progressive multiplication of cells that serves no function.

2

D-max

The depth at which electronic equilibrium occurs for photon beams. Depth of maximum absorbed dose and ionization photons in a treatment field.

3

Given Dose

Dose delivered at the depth of D-max through a single treatment field.

4

Monitor Unit

Unit of output measure used for linear accelerations.
1 mu= 1cGy

5

Isocenter

Point of intersection of 3 axis of rotation of treatment unit.
1. Gantry
2. Couch
3. Collimator

6

Central Axis

Central portion of the beam, emanating from the target. Does not diverge.

7

SSD set up

Distance from source to patient's skin

8

SAD set up

Distance from source to axis of rotation of the treatment unit.

9

Collimator field size

Open field size, projected at a reference distance, usually isocenter (100cm)

10

Blocked (Effective) Field Size

Equivalent rectangle field dimension of the open treatment area within the collimated field.

11

Photon Energy

Small pocket of electromagnetic energy.

12

Electron Energy

Negatively charged subatomic energy that can be accelerated by a variety of machines or can be admitted from decaying isotopes.

13

Wedge

Tool that modifies the asides distribution of a beam to correct for tissue in homogeneities.

14

Compensating Filter

Correct for tissue and homogeneities.

15

Cerrobend Block

Used to form (shape) the treatment field.
50% Bismuth
26.7% Lead
13.3% Tin
10% Cadmium

16

MLC

Distinct part of a linear accelerator that allows treatment field shaping through the use of motorized leaves in the head of the machine.

17

Electron Applicator (Cone)

Extended metal structure ised to restrict the useful beam to the required size.

18

Bolus

Tissue equivalent material placed on the skin to increase skin dose and even out irregular contours on the patient.

19

Beamsplit

Allows part of the beam to pass through while reflecting the other part of the beam.

20

Alpha Cradle

Immobilization devices, made from styrofoam.

21

Aquaplast

Thermoplastic immobilization device.

22

Bite Block

Used to helo immobilize and help position the tongue.

23

Positioning Lasers

Used to set up the patient correctly.

24

Single Field

treat the patient with one field

25

Parallel Opposed Field

Paid of fields directed along the same axis, form opposite sides.

26

Tangential Field

Two oblique fields, similar to a breast bridge.
(distance from midline to lateral portion)

27

Rotation/ Arc Therapy

Isocentric technique when beam moves continuously about the patient.

28

Brachytherapy

Uses radioactive material to deliver dose administered directly into the tumor.

29

Isodoses

Shows distribution of absorbed dose in points of equal dose.

30

Critical Organ Dose

Organs that limit the dose or the dose that can be tolerated by critical sructures.

31

OAR

Organs at Risk

32

Gap

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.

33

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.

34

Intensity Modulated Radiation Therapy (IMRT)

Delivers nonuniform exposure across the beam's eye view using a variety of techniques and equipment.

35

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.

36

Tomotherapy

Type of rad therapy in which the radiation is delivered slice by slice.

37

Linear Accelerator

Radiation Therapy treatment unit that accelerates electrons and produces x-rays and electron treatment.