Newest Tx Planning Qs Flashcards

1
Q

A representation of the dose in an irradiated volume, as a function of spatial position along a single line is known as a/an:
A. isodose curve
B. percent depth dose line
C. dose profile
D. dose volume histogram

A

A. isodose curve
B. percent depth dose line
C. dose profile
D. dose volume histogram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Dose rates in air express the dose measured:
A. at 10 cm depth in a phantom
B. without a phantom, with a buildup cap at a certain distance
C. with a phantom, without a buildup cap at a certain distance
D. without a build up cap or phantom with a 10 x 10 cm field size

A

B. without a phantom, with a buildup cap at a certain distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In order to make custom Cerrobend blocks, the following information is needed:
1. target-to-film distance
2. beam energy
3. patient thickness

A

All

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following radioisotopes is sometimes administered into the peritoneal cavity in the treatment of gynecological malignancies?
A. Cesium-137
B. Iridium-192
C. Iodine-131
D. Phosphorus-32

A

D. Phosphorus-32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When comparing an isodose profile from a linear accelerator with one from an orthovoltage machine, the linear accelerator isodose will have the following characteristics:
1. greater penetration
2. greater side scatter
3. higher % DD at depth
4. flatter isodose lines

A

1 3 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The field size of an X-ray or gamma ray beam is defined as the area enclosed within the boundary of the __________% depth dose line.

A

50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Wedge angle refers to:
A. the angle of the actual wedge filter
B. the angle at which an isodose curve at a specific depth is tilted as a result of the wedge being inserted in the beam
C. the angle at which an isodose curve at a specified depth is tilted with respect to the central axis of the beam

A

B. the angle at which an isodose curve at a specific depth is tilted as a result of the wedge being inserted in the beam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

While treating lateral fields in the treatment of the craniospinal axis, to avoid having the caudal margin of the lateral fields diverge into the posterior spine field, the couch should be rotated:
A. way from the collimator
B. toward the collimator
C. until the table is at 5 degrees
D. until the table is at 10 degrees

A

B. toward the collimator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When a missing tissue compensator is used, it should be placed:
A. directly on the skin surface
B. at some distance from the skin surface
C. on the end of an electron cone
D. on top of a bolus material at isocenter

A

B. at some distance from the skin surface

Rationale:
To preserve the skin-sparing effect, tissue compensators should be placed at least 15 cm from the patient’s skin surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The shape of the isodose curves depends largely upon:
1. field size
2. depth dose
3. flattening filters
4. SSD

A

1 3
Rationale:
The shape of the isodose curve depends on the field size, filters and accessories such as blocks, wedges, cones and multi-leaf collimators.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly