Final Review Flashcards
(93 cards)
1
Q
how often should the block room be assessed with air sample analysis?
A
annually
2
Q
how often should a chart check be performed?
A
- before treatment delivery
- weekly
- at treatment completion
3
Q
kV-CBCT and MV-CBCT: how often should the collision/door interlocks be checked?
A
daily
4
Q
kV-CBCT and MV-CBCT: how often should laser image treatment isocenter coincidence be checked?
A
daily
5
Q
T/F: treatment charts are legal and binding docs that can be entered into a court of law.
A
true
6
Q
what the tolerence for laser image treatment center coincidence?
A
+/- 2mm
7
Q
CT sim: what is the tolerance for the adjustment of gantry lasers with center of imaging plan
A
2mm
8
Q
CT sim: what is the tolerance for the spacing lateral wall lasers with respect to lateral gantry lasers
A
2mm
9
Q
Describe linac acceptance testing (hint: 3 things).
A
- Involves measurement of output & performance of the linac against manufacturer specs
- Establishes baseline values that are used in future dosimetric measurements
- Verifies that the machine operates within certain tolerances & mechanical integrity
10
Q
Daily QA: what’s the tolerance of x-ray output constancy
all energies
A
3%
11
Q
Daily QA of laser localization: whats the tolerance for Non-IMRT?
A
2mm
12
Q
Daily QA of laser localization: whats the tolerance for IMRT?
A
1.5 mm
13
Q
Daily QA of laser localization: whats the tolerance for SRSBRT?
A
1 mm
14
Q
Daily linac QA of ODI at isocenter: what is the tolerance for Non-IMRT?
A
2 mm
15
Q
Daily linac QA of ODI at isocenter: what is the tolerance for IMRT
A
2 mm
16
Q
Daily linac QA of ODI at isocenter: what is the tolerance for SRSBRT
A
2 mm
17
Q
on a linac how often must we check that the beam turns off when you open the door?
A
daily
18
Q
How often must the AV monitors be checked?
A
daily
19
Q
How often must the radiation area monitors be checked?
A
daily
20
Q
How often must the beam on indicator be checked?
A
daily
21
Q
whats the tolerance for the electron beam constancy?
A
2% or 2mm
22
Q
what is the tolerance for light radiation field coincidence?
A
2 mm or 1% on a side
23
Q
what is the tolerance for distance check device for lasers compared with front pointer?
A
1 mm
24
Q
what is the tolerance for cross hair centering?
A
1 mm
25
what is the tolerance for treatment couch position for Non-IMRT?
2 mm or 1 degree
26
what is the tolerance for treatment couch position for IMRT?
2 mm or 1 degree
27
what is the tolerance for treatment couch position for SRSBRT?
1 mm or 0.5 degree
28
on a linac how often must the latching of wedges be checked?
monthly
29
whats the tolerance for tabe angle?
1 degree
30
whats the tolerance for table top sag?
2 mm from baseline
31
which test looks at deviations in interleaf transmission?
picket fence test
32
What does VMAT stand for?
volumetric modulated arc therapy
33
is the treatment room a controlled or uncontrolled area?
controlled
34
is the bathroom a controlled or uncontrolled area?
uncontrolled
35
is the treatment console area controlled or uncontrolled?
controlled
36
is the exam room a controlled or uncontrolled area?
uncontrolled
37
is the waiting room a controlled or uncontrolled area?
uncontrolled
38
what's the max dose equivalent for a controlled area?
0.01 mSv/ wk (5 mSv/yr)
39
what's the max dose equivalent for an uncontrolled area?
0.02 mSv/ wk (1 mSv/yr)
40
a barrier sufficient to attenuate the useful beam to the required degree is known as?
primary barrier
41
the required barrier that protects against stray radiation (leakage and scatter) is known as?
secondary barrier
42
what factors enter into the calculation of barrier thickness?
workload
use factor
occupancy factor
distance
43
what is the definition of workload?
is usually stated in terms of weekly dose delivered at 1 m from the source. This can be estimated by multiplying the number of patients treated per week with the dose delivered per patient at 1m
44
what is the definition of use factor?
Fraction of the operating time during which the radiation under consideration is directed toward a particular barrier
45
what is the definition of occupancy factor?
Fraction of the operating time during which the area of interest is occupied by the individual
46
how is workload expressed?
dose / wk at 1m
47
in the calculation of barrier how is distance measured?
meters from radiation source to the area to be protected
48
what is the occupancy factor for areas occupied full time?
1
49
what is the occupancy factor for treatment volt doors?
1/8
50
what is the occupancy factor for the patient exam room?
1/2
51
what is the occupancy factor for employee lounges?
1/5
52
what is the occupancy factor for public toliets?
1/20
53
what is the occupancy factor for unattended parking lots?
1/40
54
T/F: the quality of leakage radiation is approximately the same as the primary beam?
true
55
Unless a maze entryway is provided, the door must provide shielding ________ to the wall surrounding the door.
equivalent
56
Is leakage radiation more or less penetrating than scattered radiation?
more penetrating
57
are concrete barriers designed for x-ray shielding sufficient for protection against neutrons?
yes
58
Which of following x-ray beams is contaminated with neutrons?
10 MeV
59
What is better to reduce neutron contamination – designing a longer maze or adding more lead shielding to the door?
longer maze
60
```
Which of the following helps minimize personnel exposure to brachytherapy sources?
A. using long forceps
B. Mobile protective shields
C. Using low E sources
D. Using radium
```
A, B, C
61
A source is considered to be leaking if there is presence of ____ microcurie or more of removable contamination is measured.
0.005
62
Which of the following can be used to measure exposure directly?
ionization chamber
63
Cutie pie is an example of:
ion chamber
64
Which of following is best for finding contamination in other low levels of radiation?
G-M detector
65
A Rascal is example of:
neutron detector
66
The film in a film monitor cannot be read after how long?
6 months
67
Which of the followings is least expensive?
film monitor
68
T/F: Thermoluminescent Dosimeter are strictly for personnel use, cannot be used with pt under treatment.
False
69
How often can a TLD be read?
once
70
T/F: OSLD are strictly for personnel use, cannot be used with pt under treatment.
false
71
OSLD can be read for as long as _____ after irradiation.
1 year
72
What kind of check is the star pattern test?
radiation isocenter
73
What kind of check is the split field test?
multiple beam alignment
74
Mechanical iso is defined as the intersection point of:
Collimator access rotation and gantry access rotation
75
An adjustable pointer device with a sharp point that may be attached to the distance-measuring rod that is attached to the accessory mount for the purpose of performing a mechanical isocenter check:
wiggler
76
What’s the tolerance for collimator rotation mech iso check?
2 mm diameter circle (when you have something bigger than that then is a prob)
77
What is the tolerance for the gantry rotation mech iso check?
+/- 1mm
78
what is the tolerance for the star pattern test?
All lines should intersect or pass within a 2mm diameter circle
79
T/F: When performing a star pattern test, all slit images should ideally intersect at one point of rad iso.
True
80
what does the split field test detect?
1. Focal Spot Displacement
2. Asymmetry of Collimator Jaws
3. Displacement in the Collimator Rotation Axis or the Gantry Rotation Axis
81
The split field test consists of double exposing a film to 2 fields ___ apart.
180°
82
What is the tolerance for calibration of leaf positions
Deviation of more than 20% will indicate positioning problems
83
What is the tolerance for wedge angles?
± 2ۣ°
84
Leakage of radiation between collimator leaves in a close position is:
a bad thing
85
Which of the terms below matches following steps?
1. Before a linac can be used or pt treatment it must be calibrated and all the beam data and treatment parameters must be obtained
2. These data is then put on treatment computer
3. The computer generates dose distributions…….
commissioning
86
How often should leak test of brachytherapy sources be performed?
every 6 months
87
Commissioning of a linac is the responsibility of:
medical physicist
88
Computer software should be commission for each treatment machine and E and must be updated
anually
89
If pt treatment plan has not been reviewed by an oncologist and physicist before the first treatment it needs to be reviewed before:
3rd frac or before 10% of dose has been delivered
90
The radiation dose that is delivered should be within ___ of the prescribed dose.
5%
91
The annual QA report should be verified by:
medical physicist
92
Defined as the transverse variation of dose relative to the central axis over the central 80% of the field size at 10-cm depth in a plane perpendicular to the CAX:
field flatness
93
What is the acceptable dose variation for field flatness:
+/- 3%
