MDCB Practice Set 4 questions with verified
answers
A Correct Answers 11. When a missing tissue compensator is used in
the treatment of the thorax, it will:
(A) reduce the variation of dose within the field.
(B) reduce the treatment time.
(C) produce increased phantom scatter.
(D) necessitate a change in dose fractionation.
A Correct Answers 20. Which of the following are advantages of using a
collimator angle of 90 degrees when treating with coplanar Intensity
Modulated Radiation Therapy (IMRT) beams?
(A) For dynamic multileaf collimation (MLC) delivery, the leaf motion
resolution along the motion axis can be finer than along the other axis,
which is limited by leaf width.
(B) Moving the leaves vertically minimizes the effect of gravity and
places less stress on the driving motors for each leaf.
(C) The interleaf leakage from the MLC leaves is directed into the target
volume areas.
(D) The MLC leaves always move vertically no matter how the gantry is
rotated.
A Correct Answers 21. Considering a 6 MV photon beam, which of the
following would result in a decrease in percent depth dose (PDD)?
, (A) decrease in field size
(B) decrease in blocking
(C) increase in treatment distance
(D) increase in energy
A Correct Answers 23. IMRT planning must consider:
(A) normal tissue tolerances
(B) depth of the target
(C) decreased exposure from head leakage
(D) shape of the target
A Correct Answers 25. The magnitude of changes observed in the dose
rate and dose distribution of an electron field
that is produced by blocking a portion of the field is dependent on
which of the following?
(A) extent of blocking
(B) distance
(C) electron gun
(D) collimator size
A Correct Answers 3. The volume of the prostate on pathological
evaluation closely correlates to the volume defined by which of the
following?
answers
A Correct Answers 11. When a missing tissue compensator is used in
the treatment of the thorax, it will:
(A) reduce the variation of dose within the field.
(B) reduce the treatment time.
(C) produce increased phantom scatter.
(D) necessitate a change in dose fractionation.
A Correct Answers 20. Which of the following are advantages of using a
collimator angle of 90 degrees when treating with coplanar Intensity
Modulated Radiation Therapy (IMRT) beams?
(A) For dynamic multileaf collimation (MLC) delivery, the leaf motion
resolution along the motion axis can be finer than along the other axis,
which is limited by leaf width.
(B) Moving the leaves vertically minimizes the effect of gravity and
places less stress on the driving motors for each leaf.
(C) The interleaf leakage from the MLC leaves is directed into the target
volume areas.
(D) The MLC leaves always move vertically no matter how the gantry is
rotated.
A Correct Answers 21. Considering a 6 MV photon beam, which of the
following would result in a decrease in percent depth dose (PDD)?
, (A) decrease in field size
(B) decrease in blocking
(C) increase in treatment distance
(D) increase in energy
A Correct Answers 23. IMRT planning must consider:
(A) normal tissue tolerances
(B) depth of the target
(C) decreased exposure from head leakage
(D) shape of the target
A Correct Answers 25. The magnitude of changes observed in the dose
rate and dose distribution of an electron field
that is produced by blocking a portion of the field is dependent on
which of the following?
(A) extent of blocking
(B) distance
(C) electron gun
(D) collimator size
A Correct Answers 3. The volume of the prostate on pathological
evaluation closely correlates to the volume defined by which of the
following?
