Chapter 15 Review Questions

Question 1

Modern photon radiation treatment units may:

a. be one device on the hospital network receiving treatment-specific information.
b. have both kV and MV imaging capabilities.
c. be controlled by multiple computer systems.
d. be designed to deliver nonisocentric treatments.
e. all of the above.

Answer 1

all the above

Question 2

Image-guided radiation therapy:

a. has been available only in the twenty-first century.
b. permits a faster patient positioning process.
c. must use registered images of the treatment position with the simulation position.
d. requires an x-ray tube mounted on the accelerator C-arm.

Answer 2

C

Question 3

MV images differ from kV images in that MV images have:

a. better soft-tissue contrast.
b. higher spatial resolution.
c. smaller amounts of metal artifacts.
d. lower radiation dose to the patient.

Answer 3

c. smaller amounts of metal artifacts.

Question 4

Four-dimensional CT:

a. requires the patient to hold his or her breath.
b. can be used to define the extent of respiratory motion.
c. would not display the target motion during the respiratory cycle.
d. images an anatomic location in the patient only once

Answer 4

b. can be used to define the extent of respiratory motion.

Question 5

Cone-beam CT differs from regular CT in that cone-beam CT:

a. uses a two-dimensional x-ray detector.
b. must use a kV source of x-rays less than 10 kV to reduce scattering.
c. produces images that have a smaller amount of scatter.
d. must be produced with a megavoltage source.

Answer 5

a. uses a two-dimensional x-ray detector.

Question 6

The respiratory cycle of a normal resting adult is approximately:

Answer 6

4 seconds

Question 7

Stereotactic treatments require:

a. a dedicated treatment unit, such as a Gamma knife.
b. that the site of treatment be in the brain.
c. a frame of reference that is used for imaging and treatment.
d. a large-dose, single-fraction treatment.

Answer 7

c. a frame of reference that is used for imaging and treatment.

Question 8

Managing the patient’s respiratory motion can be accomplished by:

a. asking the patient to hold his or her breath for more than 1 minute.
b. using vacuum bags to position the patient on the treatment table.
c. abdominal compression.
d. respiratory gating.
e. both c and d.

Answer 8

d. respiratory gating.

Question 9

One significant advantage of protons compared with photons is that:

a. protons are less expensive to produce than photons.
b. energy is deposited only to malignant tissue and not to normal tissue.
c. protons have limited range in the patient.
d. image guidance is not required

Answer 9

c. protons have limited range in the patient.

Question 10

An advantage of fiducial marker–guided treatments is that fiducial markers:

a. emit electromagnetic waves.
b. are easily imaged with ultrasound
c. contain radioactive material and can be located with a Geiger counter.
d. may be easy to track with x-rays.

Answer 10

d. may be easy to track with x-rays.