MDCB Practice Set 1 - Test 3
B - answer1. As the energy of the parallel-opposed x-rays beams of same energy
increases, it will lead to:
A. decreased dose at midplane.
B. decreased skin dose.
C. increased dose in build-up region.
D. increased dose at Dmax.
C - answer2. In the small volume treatment of bladder cancer with radiation therapy, the
patient should be
treated with:
A. a full bladder in order to spare as much small bowel as possible.
B. a full bladder in order to spread the dose evenly to the tumor.
C. an empty bladder in order to encompass tumor with reproducibility.
D. an empty bladder in order to minimize bleeding complications.
D - answer3. Although they receive the same dose, some tissues exhibit acute radiation
damage earlier than
others because they have a:
A. smaller number of metabolizing cells.
B. reduced blood flow.
C. lower number of hypoxic cells.
D. higher mitotic index.
C - answer4. A 20 cm diameter patient is treated to midplane by using a 100 cm source-
to-axis distance
(SAD) technique. If the same patient is then treated by using a 100 cm source-to-
surface
distance (SSD) technique, the monitor units would increase by approximately:
A. 10%.
B. 15%.
C. 21%.
D. 25%.
B - answer5. According to the NCRP Report #116, the annual effective dose limit for
continuous exposure to
the whole body for the general public is:
A. 0.5 mSv (0.05 rem).
B. 1.0 mSv (0.10 rem).
C. 15.0 mSv (1.50 rem).
D. 75.0 mSv (7.50 rem).
, C - answer6. Unless otherwise permitted by the NRC, brachytherapy needles and tubes
must be leak tested
by the user at intervals NOT to exceed:
A. 1 month.
B. 3 months.
C. 6 months.
D. 9 months.
D - answer7. An orthovoltage beam is used to deliver 350 cGy to a depth of 5 cm.
Calculate the timer setting
for an SSD of 52 cm given the following information:
Exposure rate = 128 R/min at 50 cm source-to-surface distance (SSD)
"cGy/R" factor = 0.95 cGy/R
Backscatter factor = 1.17
% depth dose at 5 cm = 63%
Timer error = 0
A. 3.61.
B. 3.71.
C. 4.06.
D. 4.22.
B - answer8. Which of the following image sets is used for dose calculation for photons?
A. MRI
B. CT
C. PET
D. SPECT
C - answer9. Which of the following statements is true for the conventional tangent
breast setup with the
medial aspect of the field extending from mid-sternum to the mid-axilla?
A. A high dose rate boost may be required for the lumpectomy site.
B. Inhomogeneity corrections by the TPS may reduce the role of wedges.
C. Bolus should be used to account for missing tissue compensation.
D. Tangential breast treatment is a more precise method of treatment than APBI.
C - answer10. Preplanning dosimetry for brachytherapy seed implants of the prostate
gland makes
reasonable allowances for variations due to:
A. seed migration.
B. seed misplacement.
C. organ movement.
D. lymphatic drainage.
D - answer11. Concerning the precision of treatment planning and delivery of treatment
in radiation therapy,
B - answer1. As the energy of the parallel-opposed x-rays beams of same energy
increases, it will lead to:
A. decreased dose at midplane.
B. decreased skin dose.
C. increased dose in build-up region.
D. increased dose at Dmax.
C - answer2. In the small volume treatment of bladder cancer with radiation therapy, the
patient should be
treated with:
A. a full bladder in order to spare as much small bowel as possible.
B. a full bladder in order to spread the dose evenly to the tumor.
C. an empty bladder in order to encompass tumor with reproducibility.
D. an empty bladder in order to minimize bleeding complications.
D - answer3. Although they receive the same dose, some tissues exhibit acute radiation
damage earlier than
others because they have a:
A. smaller number of metabolizing cells.
B. reduced blood flow.
C. lower number of hypoxic cells.
D. higher mitotic index.
C - answer4. A 20 cm diameter patient is treated to midplane by using a 100 cm source-
to-axis distance
(SAD) technique. If the same patient is then treated by using a 100 cm source-to-
surface
distance (SSD) technique, the monitor units would increase by approximately:
A. 10%.
B. 15%.
C. 21%.
D. 25%.
B - answer5. According to the NCRP Report #116, the annual effective dose limit for
continuous exposure to
the whole body for the general public is:
A. 0.5 mSv (0.05 rem).
B. 1.0 mSv (0.10 rem).
C. 15.0 mSv (1.50 rem).
D. 75.0 mSv (7.50 rem).
, C - answer6. Unless otherwise permitted by the NRC, brachytherapy needles and tubes
must be leak tested
by the user at intervals NOT to exceed:
A. 1 month.
B. 3 months.
C. 6 months.
D. 9 months.
D - answer7. An orthovoltage beam is used to deliver 350 cGy to a depth of 5 cm.
Calculate the timer setting
for an SSD of 52 cm given the following information:
Exposure rate = 128 R/min at 50 cm source-to-surface distance (SSD)
"cGy/R" factor = 0.95 cGy/R
Backscatter factor = 1.17
% depth dose at 5 cm = 63%
Timer error = 0
A. 3.61.
B. 3.71.
C. 4.06.
D. 4.22.
B - answer8. Which of the following image sets is used for dose calculation for photons?
A. MRI
B. CT
C. PET
D. SPECT
C - answer9. Which of the following statements is true for the conventional tangent
breast setup with the
medial aspect of the field extending from mid-sternum to the mid-axilla?
A. A high dose rate boost may be required for the lumpectomy site.
B. Inhomogeneity corrections by the TPS may reduce the role of wedges.
C. Bolus should be used to account for missing tissue compensation.
D. Tangential breast treatment is a more precise method of treatment than APBI.
C - answer10. Preplanning dosimetry for brachytherapy seed implants of the prostate
gland makes
reasonable allowances for variations due to:
A. seed migration.
B. seed misplacement.
C. organ movement.
D. lymphatic drainage.
D - answer11. Concerning the precision of treatment planning and delivery of treatment
in radiation therapy,
