MDCB Practice Set 5 - Test 13 2026
B - answer1. The most radiosensitive phase for mental retardation in the fetus from RT
accidental exposure is:
A. 0-7 weeks.
B. 8-15 weeks.
C. 16-24 weeks.
D. more than 25 weeks.
A - answer2. A pencil beam kernel is generated by:
A. Monte Carlo model computation.
B. collapsed cone calculation.
C. fast Fourier transformation.
D. pencil beam derivation.
C - answer3. A radioactive source is considered to be isotropic if it exhibitswhich of the
following characteristics?
A. Summation of the total dose is proportional to the point source.
B. Dose at depth is variable in all directions based on the placement of the source.
C. Intensity around the source is equal in all directions.
D. The total dose is a function of the size of the source calculated based on kerma rate.
C - answer4. For which of the following malignancies has hyperfractionated radiation
therapy been shown to significantly improve local control compared with standard
fractionation?
A. low-grade sarcomas
B. adult high-grade gliomas
C. head and neck cancer
D. inflammatory breast cancer
A - answer5. Linking a small group of computers within close proximity to each other in
order to share information is known as:
A. local area network.
B. network bridge.
C. application service provider.
D. client-based network.
C - answer6. As per the American Brachytherapy Society guidelines, the dose required
to treat uveal melanomas with Iodine-125 plaque brachytherapy is:
A. 50Gy prescribed to 0.5cm depth.
B. 65Gy prescribed to apex.
C. 85Gy prescribed to apex.
D. 100 Gy prescribed to 0.5cm depth.
, B - answer7. What is the minimum recommended frequency and percentage tolerance
for photon output checks on a linear accelerator?
A. Daily, 2%
B. Daily, 3%
C. Weekly, 2%
D. Monthly, 3%
D - answer8. Which of the following statementsis true for clinical electron beams?
A. The mean energy decreases as a quadratic function of depth.
B. The maximum energy is the same as the most probable energy.
C. The surface dose is inversely proportional to the electron beam energy.
D. The most probable energy is a function of the practical range (Rp).
B - answer9. In order to avoid a 5% risk of necrosis at 5 years, what dose should the
structures outlined not exceed?
A. 42 Gy
B. 52 Gy
C. 62 Gy
D. 72 Gy
A - answer10. According to QUANTEC guidelines, the dose limit to the spinal cord using
conventional fractionation with a 0.2% rate
of myelopathy is:
A. Dmax = 50 Gy Including full cord cross-section
B. Dmax = 45 Gy Including full cord cross-section
C. Dmax = 50 Gy Including partial cord cross-section
D. Dmax = 45 Gy Including partial cord cross-section
A - answer11. A patient arrives to begin radiotherapy three weeks after the treatment
plan was completed. When it is determined that the patient has gained considerable
weight and there is increased girth over the treatment area, the CMD should:
A. inform the radiation oncologist that there is an apparent change in the patient's size
and a new treatment plan may be needed.
B. treat the patient as planned and then notify the radiation oncologist.
C. make arrangements for the patient to see the department's medical dietician.
D. advise the radiation therapy technologists to monitor the patient for any adverse
effects.
A - answer12. Presence of which of the following viruses indicates a favorable
prognosis in patients with oropharyngeal cancer?
A. Human papilloma virus
B. Herpes simplex virus
C. Coxsackie virus
D. Epstein Barr virus
B - answer1. The most radiosensitive phase for mental retardation in the fetus from RT
accidental exposure is:
A. 0-7 weeks.
B. 8-15 weeks.
C. 16-24 weeks.
D. more than 25 weeks.
A - answer2. A pencil beam kernel is generated by:
A. Monte Carlo model computation.
B. collapsed cone calculation.
C. fast Fourier transformation.
D. pencil beam derivation.
C - answer3. A radioactive source is considered to be isotropic if it exhibitswhich of the
following characteristics?
A. Summation of the total dose is proportional to the point source.
B. Dose at depth is variable in all directions based on the placement of the source.
C. Intensity around the source is equal in all directions.
D. The total dose is a function of the size of the source calculated based on kerma rate.
C - answer4. For which of the following malignancies has hyperfractionated radiation
therapy been shown to significantly improve local control compared with standard
fractionation?
A. low-grade sarcomas
B. adult high-grade gliomas
C. head and neck cancer
D. inflammatory breast cancer
A - answer5. Linking a small group of computers within close proximity to each other in
order to share information is known as:
A. local area network.
B. network bridge.
C. application service provider.
D. client-based network.
C - answer6. As per the American Brachytherapy Society guidelines, the dose required
to treat uveal melanomas with Iodine-125 plaque brachytherapy is:
A. 50Gy prescribed to 0.5cm depth.
B. 65Gy prescribed to apex.
C. 85Gy prescribed to apex.
D. 100 Gy prescribed to 0.5cm depth.
, B - answer7. What is the minimum recommended frequency and percentage tolerance
for photon output checks on a linear accelerator?
A. Daily, 2%
B. Daily, 3%
C. Weekly, 2%
D. Monthly, 3%
D - answer8. Which of the following statementsis true for clinical electron beams?
A. The mean energy decreases as a quadratic function of depth.
B. The maximum energy is the same as the most probable energy.
C. The surface dose is inversely proportional to the electron beam energy.
D. The most probable energy is a function of the practical range (Rp).
B - answer9. In order to avoid a 5% risk of necrosis at 5 years, what dose should the
structures outlined not exceed?
A. 42 Gy
B. 52 Gy
C. 62 Gy
D. 72 Gy
A - answer10. According to QUANTEC guidelines, the dose limit to the spinal cord using
conventional fractionation with a 0.2% rate
of myelopathy is:
A. Dmax = 50 Gy Including full cord cross-section
B. Dmax = 45 Gy Including full cord cross-section
C. Dmax = 50 Gy Including partial cord cross-section
D. Dmax = 45 Gy Including partial cord cross-section
A - answer11. A patient arrives to begin radiotherapy three weeks after the treatment
plan was completed. When it is determined that the patient has gained considerable
weight and there is increased girth over the treatment area, the CMD should:
A. inform the radiation oncologist that there is an apparent change in the patient's size
and a new treatment plan may be needed.
B. treat the patient as planned and then notify the radiation oncologist.
C. make arrangements for the patient to see the department's medical dietician.
D. advise the radiation therapy technologists to monitor the patient for any adverse
effects.
A - answer12. Presence of which of the following viruses indicates a favorable
prognosis in patients with oropharyngeal cancer?
A. Human papilloma virus
B. Herpes simplex virus
C. Coxsackie virus
D. Epstein Barr virus
