MDCB EXAM QUESTIONS AND
ANSWERS (GRADED A+)
Which one of the following dose volume histogram (DVH) results for a pancreatic
treatment plan of conventional fractionation meets QUANTEC recommended dose
tolerances?
A. 75% of the left kidney will receive 30 Gy.
B. 50% of the right kidney will receive 40 Gy.
C. 50% of the liver will receive 42 Gy.
D. 25% of the stomach will receive 45 Gy. - ANSWER-D. 25% of the stomach will
receive 45 Gy.
An algorithm often used for electron beam dose calculations is:
A. scatter-air ratio (SAR) summations.
B. Batho & Young corrections.
C. Clarkson calculations.
D. pencil beams. - ANSWER-D. pencil beams.
Any error in the placement of adjacent fields during radiotherapy treatment is most likely
to:
A. be equally serious for beams of any penumbra.
B. be more serious with beams of smaller penumbra.
C. have no impact the treatment outcome.
D. be more serious with beams of larger penumbra. - ANSWER-B. be more serious with
beams of smaller penumbra.
A radiation oncology department has a selection of 6, 10, and 18 MV photon beams.
For a 7 beam prostate Intensity Modulated Radiation Therapy (IMRT) plan, it would be
appropriate to select a/an:
A. 6 MV photon beam because it would deliver no neutron dose and the lowest doses to
the tissue outside the planning target volume (PTV).
B. 6 MV photon beam because it would deliver some neutron dose, but give the best
dose distribution to the PTV.
C. 10 MV photon beam because it would deliver a lower neutron dose than an 18 MV
photon beam and clinically acceptable doses to the bladder and rectum.
D. 10 MV photon beam because it would deliver no neutron dose and the lowest doses
to the tissue outside the PTV. - ANSWER-A. 6 MV photon beam because it would
deliver no neutron dose and the lowest doses to the tissue outside the planning target
volume (PTV).
What can cause increased skin dose in IMRT for prostate cancer?
A. prone position
B. wedge under knees- a support device
, C. use of high energy photons
D. carbon fiber couch - ANSWER-D. carbon fiber couch
The five year cure rate for a bladder cancer tumor treated with primary radiation is:
(A) 0 - 5%
(B) 5 - 10%
(C) 25 - 30%
(D) 50 - 70% - ANSWER-(C) 25 - 30%
The five-year survival rate for a esophageal cancer tumor treated with primary radiation
is:
(A) 0 - 5%
(B) 5 - 10%
(C) 25 - 30%
(D) 50 - 70% - ANSWER-(B) 5 - 10%
The chance of having positive pelvic lymph nodes with Stage II cervical cancer is:
(A) 10 - 20%
(B) 25 - 35%
(C) 40 - 50%
(D) 60 - 70% - ANSWER-(B) 25 - 35%
The chance of having positive pelvic lymph nodes with Stage III cervical cancer is:
(A) 10 -20%
(B) 25-35%
(C) 40-50%
(D) 60-70% - ANSWER-(C) 40-50%
Characteristics of multileaf collimators, in current medical LINACs, include which of the
following:
A. accommodates all field sizes.
B. "scalloped" isodose curves in the penumbra region.
C. ability to conform to all possible field shapes.
D. inability to verify leaf shapes. - ANSWER-B. "scalloped" isodose curves in the
penumbra region.
The minimum nominal distance a tissue compensator should be placed from the skin
surface without affecting the skin sparing effect is:
A. 5.0 cm.
B. 10.0 cm.
C. 20.0 cm.
D. 25.0 cm. - ANSWER-C. 20.0 cm.
When treating with electrons typical X-ray contamination dose to a patient ranges from
approximately:
A. 0.1% to 0.4%
ANSWERS (GRADED A+)
Which one of the following dose volume histogram (DVH) results for a pancreatic
treatment plan of conventional fractionation meets QUANTEC recommended dose
tolerances?
A. 75% of the left kidney will receive 30 Gy.
B. 50% of the right kidney will receive 40 Gy.
C. 50% of the liver will receive 42 Gy.
D. 25% of the stomach will receive 45 Gy. - ANSWER-D. 25% of the stomach will
receive 45 Gy.
An algorithm often used for electron beam dose calculations is:
A. scatter-air ratio (SAR) summations.
B. Batho & Young corrections.
C. Clarkson calculations.
D. pencil beams. - ANSWER-D. pencil beams.
Any error in the placement of adjacent fields during radiotherapy treatment is most likely
to:
A. be equally serious for beams of any penumbra.
B. be more serious with beams of smaller penumbra.
C. have no impact the treatment outcome.
D. be more serious with beams of larger penumbra. - ANSWER-B. be more serious with
beams of smaller penumbra.
A radiation oncology department has a selection of 6, 10, and 18 MV photon beams.
For a 7 beam prostate Intensity Modulated Radiation Therapy (IMRT) plan, it would be
appropriate to select a/an:
A. 6 MV photon beam because it would deliver no neutron dose and the lowest doses to
the tissue outside the planning target volume (PTV).
B. 6 MV photon beam because it would deliver some neutron dose, but give the best
dose distribution to the PTV.
C. 10 MV photon beam because it would deliver a lower neutron dose than an 18 MV
photon beam and clinically acceptable doses to the bladder and rectum.
D. 10 MV photon beam because it would deliver no neutron dose and the lowest doses
to the tissue outside the PTV. - ANSWER-A. 6 MV photon beam because it would
deliver no neutron dose and the lowest doses to the tissue outside the planning target
volume (PTV).
What can cause increased skin dose in IMRT for prostate cancer?
A. prone position
B. wedge under knees- a support device
, C. use of high energy photons
D. carbon fiber couch - ANSWER-D. carbon fiber couch
The five year cure rate for a bladder cancer tumor treated with primary radiation is:
(A) 0 - 5%
(B) 5 - 10%
(C) 25 - 30%
(D) 50 - 70% - ANSWER-(C) 25 - 30%
The five-year survival rate for a esophageal cancer tumor treated with primary radiation
is:
(A) 0 - 5%
(B) 5 - 10%
(C) 25 - 30%
(D) 50 - 70% - ANSWER-(B) 5 - 10%
The chance of having positive pelvic lymph nodes with Stage II cervical cancer is:
(A) 10 - 20%
(B) 25 - 35%
(C) 40 - 50%
(D) 60 - 70% - ANSWER-(B) 25 - 35%
The chance of having positive pelvic lymph nodes with Stage III cervical cancer is:
(A) 10 -20%
(B) 25-35%
(C) 40-50%
(D) 60-70% - ANSWER-(C) 40-50%
Characteristics of multileaf collimators, in current medical LINACs, include which of the
following:
A. accommodates all field sizes.
B. "scalloped" isodose curves in the penumbra region.
C. ability to conform to all possible field shapes.
D. inability to verify leaf shapes. - ANSWER-B. "scalloped" isodose curves in the
penumbra region.
The minimum nominal distance a tissue compensator should be placed from the skin
surface without affecting the skin sparing effect is:
A. 5.0 cm.
B. 10.0 cm.
C. 20.0 cm.
D. 25.0 cm. - ANSWER-C. 20.0 cm.
When treating with electrons typical X-ray contamination dose to a patient ranges from
approximately:
A. 0.1% to 0.4%
