MDCB CERTIFICATION SET 1 |ACTUAL QUESTIONS
AND VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
The development of which of the following conditions is an example of a stochastic effect
of
radiation?
A. organ atrophy
B. second primary
C. pulmonary fibrosis
D. decreased sperm count
CORRECT ANSWER
B
Question 2
2. When an enface electron beam is used for chest wall irradiation, which of the following
describes the dose at the interface between the chest wall and lung?
A. decreased due to reduced scatter from the lung
B. decreased due to irregular surface contour effects
C. increased due to an increase in the electron fluence
D. increased due to a larger angle of electron scatter
CORRECT ANSWER
A
1
, Question 3
3. An averaged ionization chamber reading for a 10 cm x 10 cm electron applicator is 98.5
and an averaged ionization chamber reading for an electron cut-out in a 6 cm x 10 cm
applicator is 92.4. What is the monitor unit setting if 200 cGy is prescribed to 90% and the 6
cm
x 10 cm cut-out is utilized? (The output factor for 10 cm x 10 cm is 1 cGy/MU.)
A. 208 MU
B. 217 MU
C. 222 MU
D. 237 MU
CORRECT ANSWER
D
Question 4
4. Parent and daughter radioactive isotopes are said to be in secular equilibrium when
they:
A. are equal in atomic weight.
B. have the same half-life.
C. have a constant ratio of activity.
D. emit equivalent gamma energies.
CORRECT ANSWER
C
Question 5
5. To make inhomogeneity corrections in treatment plans based on CT derived anatomical
2
AND VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
The development of which of the following conditions is an example of a stochastic effect
of
radiation?
A. organ atrophy
B. second primary
C. pulmonary fibrosis
D. decreased sperm count
CORRECT ANSWER
B
Question 2
2. When an enface electron beam is used for chest wall irradiation, which of the following
describes the dose at the interface between the chest wall and lung?
A. decreased due to reduced scatter from the lung
B. decreased due to irregular surface contour effects
C. increased due to an increase in the electron fluence
D. increased due to a larger angle of electron scatter
CORRECT ANSWER
A
1
, Question 3
3. An averaged ionization chamber reading for a 10 cm x 10 cm electron applicator is 98.5
and an averaged ionization chamber reading for an electron cut-out in a 6 cm x 10 cm
applicator is 92.4. What is the monitor unit setting if 200 cGy is prescribed to 90% and the 6
cm
x 10 cm cut-out is utilized? (The output factor for 10 cm x 10 cm is 1 cGy/MU.)
A. 208 MU
B. 217 MU
C. 222 MU
D. 237 MU
CORRECT ANSWER
D
Question 4
4. Parent and daughter radioactive isotopes are said to be in secular equilibrium when
they:
A. are equal in atomic weight.
B. have the same half-life.
C. have a constant ratio of activity.
D. emit equivalent gamma energies.
CORRECT ANSWER
C
Question 5
5. To make inhomogeneity corrections in treatment plans based on CT derived anatomical
2
