MDCB review questions with complete
solutions
1625 yr CORRECT ANSWERS Ra-226 half life
3.8 d CORRECT ANSWERS Rn-222 half life
5.3y CORRECT ANSWERS Co-60 half life
30y CORRECT ANSWERS Cs-137 half life
74 d CORRECT ANSWERS Ir-192 hald life
27 d CORRECT ANSWERS Au-198 half life
60d CORRECT ANSWERS I-125 half lfie
17d CORRECT ANSWERS Pd-103 half life
8d CORRECT ANSWERS I-131 half life
13GY CORRECT ANSWERS Spinal cord Dmax SRS 1 fx
12mm Pb CORRECT ANSWERS Ra-226 HVL
12 mmPb CORRECT ANSWERS Rn-222 HVL
11 mmPb CORRECT ANSWERS Co-60 HVL
5.5 mmPb CORRECT ANSWERS Cs-137 HVL
2.5 mmPb CORRECT ANSWERS Ir-192 HVL
2.5 mmPb CORRECT ANSWERS Au-198 HVL
0.025 mmPb CORRECT ANSWERS I-125 HVL
0.008 mmPb CORRECT ANSWERS Pd-103 HVL
E/3.2 CORRECT ANSWERS D90
E/2.8 CORRECT ANSWERS D80
<10% CORRECT ANSWERS V20 for lungs for SBRT
,<12.5Gy CORRECT ANSWERS Brainstem SRS 1 fx Dmax
Co-60, Teletherapy, GammaKnife, HDR, Prostate Seed Implant CORRECT ANSWERS
List in order amount of activity from highest to lowest:
HDR, Co-60, Teletherapy, GammaKnife, Prostate Seed Implant
RX isodose Volume/PTV Volume CORRECT ANSWERS Conformity Index
<10% CORRECT ANSWERS Heart V25
D2 CORRECT ANSWERS Maximum total dose in Gy to any point 2cm or greater away
from the PTV in any direction
V12<5-10cc CORRECT ANSWERS Brain volume SRS 1 fx
2mm; 1 degree CORRECT ANSWERS TG-142 suggests monthly QA tolerances for
lateral, longitudinal, and rotational couch positions for IMRT to be
2mm, 1% on a side CORRECT ANSWERS TG-142 suggests monthly QA tolerances for
mechanical/light field coincidence for IMRT to be
2% CORRECT ANSWERS TG-142 suggests monthly QA tolerances for electron output
constancy for IMRT to be
R50 CORRECT ANSWERS the ratio of the volume of 50% of the prescription dose
isodose to the volume of the PTV
2mm CORRECT ANSWERS TG-40 suggests daily QA tolerances for laser localization
for simulators to be
2mm CORRECT ANSWERS TG-40 suggests annual QA for medical accelerator
tolerances for gantry rotation isocenter to be
<32% CORRECT ANSWERS Kidney V20
E, FS, d, SSD CORRECT ANSWERS PDD is dependent on
E, FS, d CORRECT ANSWERS TMR is dependent on
3.7 x 10^10 Bq CORRECT ANSWERS 1 Ci =? Bq
10^6 CORRECT ANSWERS mega (M)
alpha particle, 1MV, 250kVp, Co-60 CORRECT ANSWERS Rank LET from highest to
lowest: 1MV, alpha particle, 250kVp, Co-60
, 1mSv CORRECT ANSWERS 100mrad = ? dose equivalent
<12 Gy CORRECT ANSWERS Optic Nerve/Chiasm SRS 1 fx Dmax
target, Primary collimator, flattening filter, dose chambers, secondary collimator
CORRECT ANSWERS What is the correct order of components in treatment head to
generate x-rays?
6Mv CORRECT ANSWERS Which linac energy requires the highest beam current
Leukemia CORRECT ANSWERS Which is considered a stochastic effect?
Cataracts, Erythema, Sterility, Leukemia
Slightly greater CORRECT ANSWERS The lateral penumbra of a proton field is ______
as compared to a photon field.
55Gy CORRECT ANSWERS What is the ideal dose limit to 0.03cc of the brainstem?
Depth, FS, E CORRECT ANSWERS TMR are dependent on what?
Dscatter/Dair under SAD conditions CORRECT ANSWERS SAR is defined by
the pelvic sidewall/obturator nodes CORRECT ANSWERS The location of point B in a
T&O procedure is
(273.2 + T / 295)(760/P) CORRECT ANSWERS Temp/Press correction formula
slightly greater CORRECT ANSWERS The surface dose for a proton field is _______
as compared to a photon field.
Linac QA CORRECT ANSWERS TG142 is a document that gives recommendations on
what?
Prostate CORRECT ANSWERS Cs-131 is mostly common used in brachytherapy for
which kind of treatment?
1 CORRECT ANSWERS The QF for electron is:
a portion of the target is not covered by the RX dose CORRECT ANSWERS A
Conformity Index of <1.0 means what?
Brainstem CORRECT ANSWERS Which of the following would be considered a serial
structure?
Parotid gland, Brainstem, Heart, Lung
solutions
1625 yr CORRECT ANSWERS Ra-226 half life
3.8 d CORRECT ANSWERS Rn-222 half life
5.3y CORRECT ANSWERS Co-60 half life
30y CORRECT ANSWERS Cs-137 half life
74 d CORRECT ANSWERS Ir-192 hald life
27 d CORRECT ANSWERS Au-198 half life
60d CORRECT ANSWERS I-125 half lfie
17d CORRECT ANSWERS Pd-103 half life
8d CORRECT ANSWERS I-131 half life
13GY CORRECT ANSWERS Spinal cord Dmax SRS 1 fx
12mm Pb CORRECT ANSWERS Ra-226 HVL
12 mmPb CORRECT ANSWERS Rn-222 HVL
11 mmPb CORRECT ANSWERS Co-60 HVL
5.5 mmPb CORRECT ANSWERS Cs-137 HVL
2.5 mmPb CORRECT ANSWERS Ir-192 HVL
2.5 mmPb CORRECT ANSWERS Au-198 HVL
0.025 mmPb CORRECT ANSWERS I-125 HVL
0.008 mmPb CORRECT ANSWERS Pd-103 HVL
E/3.2 CORRECT ANSWERS D90
E/2.8 CORRECT ANSWERS D80
<10% CORRECT ANSWERS V20 for lungs for SBRT
,<12.5Gy CORRECT ANSWERS Brainstem SRS 1 fx Dmax
Co-60, Teletherapy, GammaKnife, HDR, Prostate Seed Implant CORRECT ANSWERS
List in order amount of activity from highest to lowest:
HDR, Co-60, Teletherapy, GammaKnife, Prostate Seed Implant
RX isodose Volume/PTV Volume CORRECT ANSWERS Conformity Index
<10% CORRECT ANSWERS Heart V25
D2 CORRECT ANSWERS Maximum total dose in Gy to any point 2cm or greater away
from the PTV in any direction
V12<5-10cc CORRECT ANSWERS Brain volume SRS 1 fx
2mm; 1 degree CORRECT ANSWERS TG-142 suggests monthly QA tolerances for
lateral, longitudinal, and rotational couch positions for IMRT to be
2mm, 1% on a side CORRECT ANSWERS TG-142 suggests monthly QA tolerances for
mechanical/light field coincidence for IMRT to be
2% CORRECT ANSWERS TG-142 suggests monthly QA tolerances for electron output
constancy for IMRT to be
R50 CORRECT ANSWERS the ratio of the volume of 50% of the prescription dose
isodose to the volume of the PTV
2mm CORRECT ANSWERS TG-40 suggests daily QA tolerances for laser localization
for simulators to be
2mm CORRECT ANSWERS TG-40 suggests annual QA for medical accelerator
tolerances for gantry rotation isocenter to be
<32% CORRECT ANSWERS Kidney V20
E, FS, d, SSD CORRECT ANSWERS PDD is dependent on
E, FS, d CORRECT ANSWERS TMR is dependent on
3.7 x 10^10 Bq CORRECT ANSWERS 1 Ci =? Bq
10^6 CORRECT ANSWERS mega (M)
alpha particle, 1MV, 250kVp, Co-60 CORRECT ANSWERS Rank LET from highest to
lowest: 1MV, alpha particle, 250kVp, Co-60
, 1mSv CORRECT ANSWERS 100mrad = ? dose equivalent
<12 Gy CORRECT ANSWERS Optic Nerve/Chiasm SRS 1 fx Dmax
target, Primary collimator, flattening filter, dose chambers, secondary collimator
CORRECT ANSWERS What is the correct order of components in treatment head to
generate x-rays?
6Mv CORRECT ANSWERS Which linac energy requires the highest beam current
Leukemia CORRECT ANSWERS Which is considered a stochastic effect?
Cataracts, Erythema, Sterility, Leukemia
Slightly greater CORRECT ANSWERS The lateral penumbra of a proton field is ______
as compared to a photon field.
55Gy CORRECT ANSWERS What is the ideal dose limit to 0.03cc of the brainstem?
Depth, FS, E CORRECT ANSWERS TMR are dependent on what?
Dscatter/Dair under SAD conditions CORRECT ANSWERS SAR is defined by
the pelvic sidewall/obturator nodes CORRECT ANSWERS The location of point B in a
T&O procedure is
(273.2 + T / 295)(760/P) CORRECT ANSWERS Temp/Press correction formula
slightly greater CORRECT ANSWERS The surface dose for a proton field is _______
as compared to a photon field.
Linac QA CORRECT ANSWERS TG142 is a document that gives recommendations on
what?
Prostate CORRECT ANSWERS Cs-131 is mostly common used in brachytherapy for
which kind of treatment?
1 CORRECT ANSWERS The QF for electron is:
a portion of the target is not covered by the RX dose CORRECT ANSWERS A
Conformity Index of <1.0 means what?
Brainstem CORRECT ANSWERS Which of the following would be considered a serial
structure?
Parotid gland, Brainstem, Heart, Lung
