AMY HEATH SIM AND TRT PLANNING (CH 6)

Question 1

Which of the following is a negative contrast agent?

A. Air
B. Iodine
C. Barium sulfate
D. Nonionic venous contrast

Answer 1

A. Air

Question 2

Which of the following is not true regarding iodine contrast?

A. Can be administered intravenously
B. Kidney function must be checked prior to administration
C. Is ionic only
D. Patients allergic to shellfish should not receive iodine contras

Answer 2

C. Is ionic only

Question 2

Prior to the administration of intravenous contrast, you should assess the patient for:

A. Shellfish allergy
B. Lung function
C. Joint pain
D. GI complications

Answer 2

A. Shellfish allergy

Question 2

The hyoid bone is located at what vertebral level?

A. C1
B. C3
C. T1
D. T3

Answer 2

B. C3

Question 3

The SSN corresponds to vertebral level:

A. C3
B. T3
C. T6
D. L3

Answer 3

B. T3

Question 4

SSN stands for what?

Answer 4

Suprasternal Notch

Question 5

An example of a positioning device is:

A. Thermoplastic mask
B. Chemical mold
C. Head holder
D. Vacuum mold

Answer 5

C. Head holder

Question 6

7. What positioning device is used to move a patient’s small bowel out of pelvic treatment fields?

A. Shoulder assistance straps
B. Bellyboard
C. Wingboard
D. Thermoplastic device

Answer 6

B. Bellyboard

Question 7

8. Thermoplastic immobilization devices are used to immobilize the:

A. Head and neck
B. Chest
C. Abdomen
D. Pelvis

Answer 7

A. Head and neck

Question 8

9. When obtaining images through conventional simulation, what is true regarding mA?

A. Controls contrast of the image
B. Represents the quality of the beam
C. Controls density of the image
D. All of the above are true

Answer 8

C. Controls density of the image

-Milliamperage (mA) is the quantity of beam and controls overall density.
-Kilovoltage potential (KvP) is the quality of beam and controls contrast.

Question 9

10. What is not a step of CT simulation?

A. Scanning the area of interest per physician order
B. Imaging with slices of 2–8 mm
C. Taking orthogonal images
D. Ensuring the patient anatomy and simulation marks are included in field of
view as the image is reconstructed.

Answer 9

C. Taking orthogonal images

Question 10

11. After CT simulation, what must be documented by the radiation therapist?

A. Gantry angle
B. Collimator angle
C. Field size
D. Patient setup

Answer 10

D. Patient setup

Question 11

What is not included in the CTV?

A. GTV
B. Margin for motion
C. Microscopic disease
D. All of the above are included in the CTV

Answer 11

B. Margin for motion

Question 12

13. What volume accounts for the patient’s physiologic movement, such as breathing?

A. Clinical target volume
B. Internal margin
C. Gross target volume
D. Motion volume

Answer 12

B. Internal margin

Question 13

What term describes critical structures in or near the treatment field?

A. Internal target volume
B. Organs at risk
C. Irradiated volume
D. Internal margin

Answer 13

B. Organs at risk

Question 14

15. Which of the following is true regarding the forward planning technique?

A. Plan is optimized after fields are designed
B. Computer design treatment fields based on set criteria
C. Is used for IMRT planning
D. Is only used for brachytherapy planning

Answer 14

A. Plan is optimized after fields are designed

Question 15

16. Which of the following are considered when designing fields and beam arrangements? (Choose all correct answers).

A. Total dose
B. Beam energy
C. Patient setup

Answer 15

A. Total dose
B. Beam energy
C. Patient setup

Question 16

Which of the following tumors would best be treated with an arc treatment?

A. Central lung tumor
B. Inflammatory breast cancer
C. Ewings sarcoma
D. Nasopharyngeal tumor

Answer 16

A. Central lung tumor

Question 17

18. Which of the following beam modifying devices would not be used to compensate for missing tissue in a patient?

A. Cerrobend blocks
B. Bolus
C. Compensating filters
D. Wedges

Answer 17

A. Cerrobend blocks

Question 18

Blocks are ____ HVL thick.

A. 1
B. 3
C. 5
D. 7

Answer 18

C. 5

Question 19

20. Multileaf collimators (MLC) are made of:

A. Lipowitz metal
B. Tungsten
C. Lead
D. Brass

Answer 19

B. Tungsten

Question 20

***21. What device would be used in order to compensate for missing tissue as well as increase the dose to the skin?

A. Compensating filter
B. Bolus
C. Wedge
D. Hand block

Answer 20

B. Bolus

Question 21

22. What is a limitation of using wedges in a patient’s treatment plan?

A. Increased time needed for treatment planning
B. Field size limitations
C. Limitations in gantry angles that can be used
D. Little variety in available wedge angles

Answer 21

B. Field size limitations

Question 22

23. Calculate the hinge angle when using 30° wedges in a wedge pair field arrangement.

A. 60°
B. 120°
C. 180°
D. 240°

Answer 22

B. 120°

Question 23

24. The _______________ is the projection of what the treatment field will look like, from the point of view from the origin of the beam. A. Beam’s eye view B. Isodose distribution C. Dose volume histogram D. Field size view

Answer 23

A. Beam’s eye view

Question 24

***25. What is not included in the radiation therapy treatment prescription? A. Dose per fraction B. Beam-modifying devices C. Treatment volume D. Patient position

Answer 24

D. Patient position

Question 25

Calculate the equivalent square for a 6×12 cm field size. A. 4×4 cm B. 6×6 cm C. 8×8 cm D. 10×10 cm

Answer 25

C. 8×8 cm

Question 26

The ________ factor is the ratio of dose at dmax for field size to dose at dmax for standard field size. A. Attenuation B. Output C. Back scatter D. Tissue maximum

Answer 26

B. Output

Question 27

28. Backscatter factor is the: A. Ratio of dose with modifier in beam to dose without modifier in beam B. Ratio of dose at dmax in phantom to dose at dmax in air C. Target-to-axis distance D. Ratio of absorbed dose at depth to dose at dmax

Answer 27

B. Ratio of dose at dmax in phantom to dose at dmax in air

Question 28

Percent depth dose increases with: A. Increased energy B. Decreased field size C. Increased depth D. All of the above

Answer 28

A. Increased energy

Question 29

30. What is the Mayneord’s factor for a patient who was originally treated at 100 cm SSD to a depth of 5 cm with a 10× photon beam, but now needs to be treated at 110 cm SSD? A. 0.990 B. 0.993 C. 1.003 D. 1.010

Answer 29

C. 1.003

Question 30

31. The ratio of scattered dose at depth in phantom to scatter dose at depth in air is: A. Tissue-air ratio (TAR) B. Scatter-air ratio (SAR) C. Tissue maximum ratio (TMR) D. Tissue phantom ratio (TPR)

Answer 30

B. Scatter-air ratio (SAR)

Question 31

32. TAR is independent of: A. Energy B. Field size C. Depth D. SSD

Answer 31

D. SSD -TAR increases with increased energy and increased field size, decreases with increased depth and is independent of SSD. This factor is used in SAD calculations. TAR=BSF when measured at dmax.

Question 32

What does TAR stand for?

Answer 32

Tissue Air Ratio

Question 33

33. Calculate the gap required for adjacent fields (Field A—length 12, Field B— length 20) treated at 100 cm SSD with 6 MV photon beams to a treatment depth of 5 cm. A. 0.5 cm B. 0.8 cm C. 1.3 cm D. 1.5 cm

Answer 33

B. 0.8 cm

Question 34

34. Calculate the monitor units needed for a patient being treated AP/PA to their abdomen with a 12×16 cm field, SSD=100 cm, treated midplane to a depth of 7 cm, Sc=1.08, Sp=1.007, %dd=76 %, tumor dose to target is 180 cGy A. 90 MU B. 101 MU C. 109 MU D. 118 MU

Answer 34

C. 109 MU

Question 35

35. A patient is being treated isocentrically with four fields (equally weighted) to their pelvis using 10× photons. The AP SSD is 90 cm, Right Lateral SSD is 78 cm, PA SSD is 90 cm and left lateral SSD is 82 cm. The total tumor dose per fraction is 180 cGy. What information will you need before you can look up the factors to complete the monitor unit calculation? A. Field size B. Patient position C. Location of patient tattoos D. Gantry angles

Answer 35

A. Field size

Question 36

36. The practical range of a 12 MeV electron beam is: A. 3 cm B. 4 cm C. 6 cm D. 12 cm

Answer 36

C. 6 cm

Question 37

How many monitor units are needed for a lumpectomy boost electron treatment, prescribed to the 80 % isodose line? The Cfs for the treatment field using a 10 × 10 cm cone with minimal blocking is 1.05. The dose per field is 200 cGy. A. 211 MU’s B. 238 MU’s C. 190 MU’s D. 214 MUs

Answer 37

B. 238 MU’s