A tissue equivalent material, usually large enough to provide full scatter conditions of a beam. These are used to predict the dose distribution in an actual patient.
What is phantoms.
100
This calculation cannot be used in isocentric techniques, because of source to skin distance dependence.
What is PPD.
100
1/4 of the electron energy in Mev. It is the most useful percent depth dose for electron treatments.
What is 90% dose line.
100
The probability of occurrence increases with increasing absorbed dose, but the severity of the effect dose not depend on the magnitude of absorbed dose. (Used with x-rays)
What is stochastic effects.
100
This type of treatment uses material that is formed to conform to a body part and are treated with brachytherapy.
What is surface mold brachytherapy.
200
Phantoms that are not homogenous.
What is an anthropomorphic phantom.
200
As the field size increases this factor increases because of increase collimator scatter.
What is output factor.
200
In this type of collision of electrons: kinetic energy is not lost, it may be redistributed among the particles involved in the collision.
What is elastic collisions.
200
Annual occupational exposure.
What is 50 mSv or 5 rem.
200
Radioactive seeds are implanted into tissues in this type of brachytherapy.
What is interstitial brachytherapy.
300
The quotient (as a percentage) of the absorbed dose at any depth to the absorbed dose at a fixed reference depth along the central axis.
What is percentage depth dose (PDD).
300
ratio of the dose at a given point in a phantom to the dose at the same point at a fixed reference depth.
What is tissue phantom ratio (TPR).
300
This process is a result of incident electrons having an inelastic collision with the nucleus of an atom. This is more common in high Z materials.
What is Bremsstrahlung.
300
Annual public exposure.
What is 5 mSv or 0.5 rem.
300
Type of treatment usually used for cervical, uterine, or vaginal boosts.
What is intracavitary brachytherapy.
400
Energy transferred from photons to electrons.
What is kerma.
400
Ratio of the dose at a given point in a phantom to the dose at the same point at the reference depth of max dose.
What is tissue max ratio (TMR).
400
Unlike x-ray beams, electron beams emanate from what kind of source.
What is virtual source.
400
P = (WUT/d^2) (B)
What is the primary barrier calculation.
400
In an HDR afterloader, this is used to test the catheter line for kinks and obstruction before the source is used.
What is a dummy wire.
500
Energy absorbed by tissue from electrons.
What is absorbed dose.
500
This calculation is used for isocenter treatments and
rotational treatments
What is tissue-air ratio (TAR).
500
This happens in electron treatments because of bremsstrahlung interactions with the collimation and body tissues.
What is x-ray contamination.
500
A device that doesn't measure dose, but is used to detect a radiation presence.