MDCB Practice Test 3 questions with verified
answers
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: Ans✓✓✓ 21%
A breast treatment technique: Ans✓✓✓ may not require wedges if
doses are corrected for tissue inhomogenieties
A staging laparotomy with splenectomy in Hodgkin's disease has the
following implications for radiation therapy: Ans✓✓✓ possible
improvement in hematologic tolerance
According to the National Council on Radiation Protection and
Measurements (NCRP) (#116) guidelines, the annual effective dose limit
for continuous exposure to the whole body for the general public is:
Ans✓✓✓ 1.0 mSv (0.10 rem)
Although they receive the same dose, some tissues exhibit acute
radiation damage earlier than others because they have a: Ans✓✓✓
higher mitotic index
, 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 Ans✓✓✓ 4.22
Autoradiography of an encapsulated brachytherapy source is:
Ans✓✓✓ a test for gross nonuniformity of the radionuclide within a
source capsule
Bolus is often used in electron beam therapy for what purpose?
Ans✓✓✓ reduce the penetration of the electrons in parts of the field
Bremsstrahlung radiation may be produced by: Ans✓✓✓ electrons
striking high atomic number targets
Concerning the precision of treatment planning and delivery of
treatment in radiation therapy, the greatest source of uncertainty is:
Ans✓✓✓ patient and organ motion during treatment
answers
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: Ans✓✓✓ 21%
A breast treatment technique: Ans✓✓✓ may not require wedges if
doses are corrected for tissue inhomogenieties
A staging laparotomy with splenectomy in Hodgkin's disease has the
following implications for radiation therapy: Ans✓✓✓ possible
improvement in hematologic tolerance
According to the National Council on Radiation Protection and
Measurements (NCRP) (#116) guidelines, the annual effective dose limit
for continuous exposure to the whole body for the general public is:
Ans✓✓✓ 1.0 mSv (0.10 rem)
Although they receive the same dose, some tissues exhibit acute
radiation damage earlier than others because they have a: Ans✓✓✓
higher mitotic index
, 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 Ans✓✓✓ 4.22
Autoradiography of an encapsulated brachytherapy source is:
Ans✓✓✓ a test for gross nonuniformity of the radionuclide within a
source capsule
Bolus is often used in electron beam therapy for what purpose?
Ans✓✓✓ reduce the penetration of the electrons in parts of the field
Bremsstrahlung radiation may be produced by: Ans✓✓✓ electrons
striking high atomic number targets
Concerning the precision of treatment planning and delivery of
treatment in radiation therapy, the greatest source of uncertainty is:
Ans✓✓✓ patient and organ motion during treatment
