CLRS305 Linacs & CH8 Tech

Hypofractionation

higher daily dose but less protraction

Protraction

the days of tx, achieve radiobiological effect by fractionation

Linacs contain ___ frequency _____ waves

high, electromagnetic

Electron gun contains…

heated filament

Flattening filter

shaped like a triangle to make the beam the same energy level

Upper & lower jaws

x and y jaws, can be manipulated

Why do we use scattering foil with electrons?

b/c electrons have mass

EDW

enhanced dynamic wedge - moving while beam is on

Pneumatic system

using air pressure to move things in and out

Primary collimator

doesn’t move

Secondary collimator

adjustable

Flattening filter is made of…

tungsten m

____ rotates around isocenter

everything

T or F: everything is mounted isocentricly

true

MU (monitor units)

amount of radiation given with note of depth, field size, etc.

Informed consent

b4 recieve Tx, explanation of status, tx alternatives, consequences

Verify and record

double check each other, verification of tx; MU, gantry, collimator, table position, arc vs fixed treat, beam modifications - all monitored

Changes

physician sign and date, electronic charting; fractionation, dose, addition or deletion of blocks or bolus

IMRT

deliver evenly distributed rad dose to target volume while minimizing dose to surrounding - MLC

VMAT (arc)

able to do higher volume but limit dose and control dose a lot better for tx

SRS

intracranial; higher dose

SBRT

rest of body; higher dose

TBI

total body irradiation (bone marrow transplant ?)

Adjacent fields

treating fields that are side by side

T or F: SSD never be greater than 100

true