Chapter 8 WS

Question 1

What is EMR?

Answer 1

Electronic Medical Record

Question 2

define EMR

Answer 2

Computerized account chronicling the care process story of a patient from presentation through their diagnosis and treatment.

Question 3

what is EPID?

Answer 3

electronic portal imaging device

Question 4

define EPID

Answer 4

system producing near real-time portal images on a computer screen for evaluation.

Question 5

what is V & R

Answer 5

verification and record

Question 6

define V & R

Answer 6

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.

Question 7

what is QA

Answer 7

quality assurance

Question 8

define QA

Answer 8

systematic monitoring of the quality and appropriateness of patient care with an emphasis on performance levels.

Question 9

what is included in a treatment record

Answer 9

documents the delivery of treatments;

• displays fractional and cumulative doses,
• machine settings,
• verification imaging;
• documents the ordering and execution of prescribed changes.

Question 10

define protraction

Answer 10

time period during which the treatment will be given

Question 11

define treatment technique

Answer 11

number, type, and orientation of treatment fields

Question 12

define beam modifiers

Answer 12

Devices that change the shape of the treatment field or distribution of the radiation at depth

Examples: independent jaws, MLCs, wedges, compensators, and bolus.

Question 13

define isocenter

Answer 13

Point of intersection of the three axes of rotation (gantry, collimator, and base of couch) of the treatment unit.

Question 14

what is another name for “treatment field”

Answer 14

portal

Question 15

define BEV

Answer 15

Allows anatomy to be viewed from the perspective of the radiation beam.

Question 16

define verification imaging

Answer 16

The documentation of treatment through radiographic or electronic imaging devices.

Question 17

define localization

Answer 17

identification of hidden anatomy relative to observable or palpable surface landmarks

Question 18

define fiducial markers

Answer 18

fixed reference points against which other objects can be measured

Question 19

define ODI and what is it used for

Answer 19

Optical distance indicator also called a range finder and is used to read the SSD (source to skin distance)

Question 20

define collimation

Answer 20

the arrangement of shielding material designed to define the x and y dimensions of the field.

Question 21

what is cerrobend composed of and what is it used for

Answer 21

Bismuth(50%), Lead(26.7%), Tin (13.3%), cadmium (10%) (easy way to remember: BLT w/cheese ☺)

Used for shielding.

Question 22

what is a bolus and what is it used for

Answer 22

Tissue equivalent material that is usually placed on the patient to increase the skin dose and/or even out irregular contours in the patient.

Question 23

define hinge angle

Answer 23

the measure of the angle between central rays of two intersecting treatment beams.

Question 24

what are interlocks

Answer 24

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.

Question 25

define Mus

Answer 25

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.

Question 26

define MLCs

Answer 26

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

Question 27

define triangulation

Answer 27

Lining the patient up to the three points marked on the patient using the three machine-aligned lasers.

Question 28

5 main items that must be included in the Radiation Therapy prescription

Answer 28

- 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.)

Question 29

while the patient is being treated, should the lights be on or off?

Answer 29

on so you can easily see the patient

Question 30

list two methods for identifying a patient

Answer 30

First and last name, date of birth, may use bar coding systems and wrist braclets. Along with name and dob.

Question 31

what is a time - out

Answer 31

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.

Question 32

True or False: the three point localization marks placed on the patient for triangulation will always coincide with the treatment isocenter

Answer 32

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)

Question 33

what is a portal image (used to be a port film)

Answer 33

An image that verifies the BEV(Beams eye view) path, including the beam shape, position and projection of the beams central axis.

Question 34

the thin end of the wedge is called the ______

Answer 34

toe

Question 35

the thick end of the wedge is call the _____

Answer 35

heel

Question 36

what is the hinge angle for POP fields (portals)

Answer 36

180 degrees

Question 37

what is IMRT an acronym for

Answer 37

intensity modulated radiation therapy

Question 38

What is the difference between conformal and IMRT treatment in regards to the dose being delivered during treatment?

Answer 38

IMRT allows a higher dose to be delivered to the target while delivering less dose to the normal structures around it.

Question 39

What is the difference between the step and shoot (segmental MLC) and the sliding window technique (dynamic MLC) IMRT treatment?

Answer 39

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.