Chapter 8 WS Flashcards
What is EMR?
Electronic Medical Record
define EMR
Computerized account chronicling the care process story of a patient from presentation through their diagnosis and treatment.
what is EPID?
electronic portal imaging device
define EPID
system producing near real-time portal images on a computer screen for evaluation.
what is V & R
verification and record
define V & R
Verification and Record systems provide validated parameters from the treatment plan to the treatment machine for setup and delivery.
Actual machine settings are compared with those most recently prescribed for a particular field and prevent initiation of the treatment beam if settings vary outside a specified tolerance range.
what is QA
quality assurance
define QA
systematic monitoring of the quality and appropriateness of patient care with an emphasis on performance levels.
what is included in a treatment record
documents the delivery of treatments;
- displays fractional and cumulative doses,
- machine settings,
- verification imaging;
- documents the ordering and execution of prescribed changes.
define protraction
time period during which the treatment will be given
define treatment technique
number, type, and orientation of treatment fields
define beam modifiers
Devices that change the shape of the treatment field or distribution of the radiation at depth
Examples: independent jaws, MLCs, wedges, compensators, and bolus.
define isocenter
Point of intersection of the three axes of rotation (gantry, collimator, and base of couch) of the treatment unit.
what is another name for “treatment field”
portal
define BEV
Allows anatomy to be viewed from the perspective of the radiation beam.
define verification imaging
The documentation of treatment through radiographic or electronic imaging devices.
define localization
identification of hidden anatomy relative to observable or palpable surface landmarks
define fiducial markers
fixed reference points against which other objects can be measured
define ODI and what is it used for
Optical distance indicator also called a range finder and is used to read the SSD (source to skin distance)
define collimation
the arrangement of shielding material designed to define the x and y dimensions of the field.
what is cerrobend composed of and what is it used for
Bismuth(50%), Lead(26.7%), Tin (13.3%), cadmium (10%) (easy way to remember: BLT w/cheese ☺)
Used for shielding.
what is a bolus and what is it used for
Tissue equivalent material that is usually placed on the patient to increase the skin dose and/or even out irregular contours in the patient.
define hinge angle
the measure of the angle between central rays of two intersecting treatment beams.
what are interlocks
Safety switches blocking or terminating radiation production. Prevent beam initiation and include alerts prompting completion of treatment setup and safety procedures, including closing the door, beam-modifier placement such as wedges and electron cones. Also interlock will prevent initiation of beam if water temp., water pressure, and vacuum system measurements not in range. Anything not acceptable will trigger a fault on the console.
define Mus
Monitor Units-Unit of output measure for linear accelerators
Calibrated so that 1 MU delivers 1cGy for a standard reference field size (Usually 10 X 10) at a standard reference depth at a standard source-to-calibration point.
define MLCs
MultiLeaf Collimator, They are found in the head of the gantry and are used for field shaping and blocking through the use of motorized leaves in the head of the machine
define triangulation
Lining the patient up to the three points marked on the patient using the three machine-aligned lasers.
5 main items that must be included in the Radiation Therapy prescription
- anatomical site,
- total radiation dose,
- individual treatment dose (fractionation),
- time period (number of fractions)during which the treatment will be given (protraction),
- energy (method of delivery so the energy will tell whether it is photons or electrons), depth of treatment (ex. Midplane or per plan).
Note: As you go to clinic, you will find that some radiation oncologists will include additional information in the prescription and some W/L p. 159 May also include the type and orientation of treatment beams (ex. IMRT, AP/PA, etc.)
while the patient is being treated, should the lights be on or off?
on so you can easily see the patient
list two methods for identifying a patient
First and last name, date of birth, may use bar coding systems and wrist braclets. Along with name and dob.
what is a time - out
A standardize approach to verifying that you are treating the right patient, area, etc.
Ex. At Moffitt after setting up the patient, the therapist will complete the time out by stating “We are treating Mr. Smith to the Prostate, with a full bladder, etc….” this is done in the treatment room and other therapists have to concur. Other sites check off a list of things in ARIA and call this a time-out. So each site has its own standardize approach.
True or False: the three point localization marks placed on the patient for triangulation will always coincide with the treatment isocenter
false
The three points are placed in a stable location. Isocenter will not always coincide with 3 stable points (ex. on the lung patient we practice triangulating in the VERT, the marks near the underarm coincide with the AP isocenter mark but this is not a stable place to triangulate to, so we triangulate to the tattoos I placed on the patient then move to the AP mark)
what is a portal image (used to be a port film)
An image that verifies the BEV(Beams eye view) path, including the beam shape, position and projection of the beams central axis.
the thin end of the wedge is called the ______
toe
the thick end of the wedge is call the _____
heel
what is the hinge angle for POP fields (portals)
180 degrees
what is IMRT an acronym for
intensity modulated radiation therapy
What is the difference between conformal and IMRT treatment in regards to the dose being delivered during treatment?
IMRT allows a higher dose to be delivered to the target while delivering less dose to the normal structures around it.
What is the difference between the step and shoot (segmental MLC) and the sliding window technique (dynamic MLC) IMRT treatment?
Step and shoot: IMRT technique where the leaves reposition then come to rest while the beam is delivered in multiple segments at each gantry angle.
Sliding Window: IMRT technique where the MLCs move from one side of the field to the other while the beam is on.
