Flashcards in Image Guided Radiotherapy Deck (20):
In general most tumours are radio resistant if there not in the?
External beam radiation therapy with positional verification using imaging prior to each fraction
IGRT is not limited to?
3DCRT, IMRT, VMAT, radiosurgery, stereotactic
IGRT is used for ?
What is a systematic error?
Deviation that occurs in the same direction and of a similiar magnitude for each fraction
What is a random error?
Is a deviation that can vary in direction and magnitude during the treatment
How do you correct for error?
GTV-disease we can see
PTV-where you treat
Is MRI better than CT imaging for certain things?
Yes MRI shows better delineation of soft tissue and water!
What movements can we predict?
Bladder filling minute to minute
Heart beat both second to second
What movements can't we predict?
Skin motion day to day
Prostate motion hour to hour
Peristalsis second to second
What is interfractional?
Varies day to day
What is intrafraxtional?
Movement during treatment
IGRT detects what?
Positional errors weight loss substantial organ deformation changes in respiratory motion
Soft tissue matching?
Is matching prostate rectum bladder
Outside representation of the patient
What are transponders?
Magnetic implants allow for target delineation with out ionising energy used for live tracking
How many structures should be used to match?
Imaging for palliative and radical?
Should be no less rigorous
For palliative patient they expand the margins and tolerance
More comfortable for patients
What is the ptv margin
2.5 systematic +0.7 random