MDCB QUESTIONS AND ANSWERS
100% CORRECT
What is the approximate density of healthy tissue? - ANSWER-0.30 g/cc
The accelerator component that ejects electrons in to the linear accelerator is? -
ANSWER-Electron gun
Radiation damage to the fetus resulting in severe birth defects would most often occur
when radiation was delivered at which time post-fertilization? - ANSWER-3-12 Weeks
The decay constant for a radioactive source that has a half-life of 60 days is? -
ANSWER-.693/60=0.0155 or 0.012
The function of a maze to a megavoltage treatment room is to: - ANSWER-minimize
radiation levels at the door
The anatomic location of the seminal vesicles is: - ANSWER-superior to the prostate
and angled posteriorly near the rectum.
Two missed treatment days due to LINAC malfunction: - ANSWER-may be
compensated by adding the same or even more fractions to the treatment course with
weekend treatment if possible.
The relative skin dose for a given energy photon beam: - ANSWER-increases with
increasing field size.
Radiographs taken at which of the following sets of angles would be orthogonal? -
ANSWER-85 and 355 degrees
he tissue-maximum ratio (TMR) is used in place of the tissue-air ratio (TAR) for
megavoltage beams because, as energy increases, the: - ANSWER-dose in free space
becomes difficult to measure.
For a 4-field box technique, which of the following will deliver the lowest dose to the
femoral heads? - ANSWER-100 source-to-surface distance (SSD), equal dmax dose to
all fields
According to the American Association of Physicists in Medicine (AAPM) Task Group
Report #142, the constancy of dose per monitor unit for photon beams of a linear
accelerator should be checked: - ANSWER-daily.
100% CORRECT
What is the approximate density of healthy tissue? - ANSWER-0.30 g/cc
The accelerator component that ejects electrons in to the linear accelerator is? -
ANSWER-Electron gun
Radiation damage to the fetus resulting in severe birth defects would most often occur
when radiation was delivered at which time post-fertilization? - ANSWER-3-12 Weeks
The decay constant for a radioactive source that has a half-life of 60 days is? -
ANSWER-.693/60=0.0155 or 0.012
The function of a maze to a megavoltage treatment room is to: - ANSWER-minimize
radiation levels at the door
The anatomic location of the seminal vesicles is: - ANSWER-superior to the prostate
and angled posteriorly near the rectum.
Two missed treatment days due to LINAC malfunction: - ANSWER-may be
compensated by adding the same or even more fractions to the treatment course with
weekend treatment if possible.
The relative skin dose for a given energy photon beam: - ANSWER-increases with
increasing field size.
Radiographs taken at which of the following sets of angles would be orthogonal? -
ANSWER-85 and 355 degrees
he tissue-maximum ratio (TMR) is used in place of the tissue-air ratio (TAR) for
megavoltage beams because, as energy increases, the: - ANSWER-dose in free space
becomes difficult to measure.
For a 4-field box technique, which of the following will deliver the lowest dose to the
femoral heads? - ANSWER-100 source-to-surface distance (SSD), equal dmax dose to
all fields
According to the American Association of Physicists in Medicine (AAPM) Task Group
Report #142, the constancy of dose per monitor unit for photon beams of a linear
accelerator should be checked: - ANSWER-daily.
