dosimetry final questions with verified answers
1 Gy is equal to Ans✓✓✓ -100 rad
-10^2 cGy
-1 J/kg
a conformal beam arrangement will giver a __ dose to a critical
structure than a nonconformal beam arrangement Ans✓✓✓ lower
a correction applied to the %DD to account for extended distance
Ans✓✓✓ mayneord f factor
a decrease in field size yields a __ and increase in __ Ans✓✓✓
decrease in Sc, MU
a field dimension at depth is (smaller, larger, the same) as the field size
on the skin Ans✓✓✓ larger
a non-coplanar beam is defined as Ans✓✓✓ beams with couch angle
a percent depth dose increases in value as Ans✓✓✓ the beam energy
and SSD increase and the depth decreases
,a percent depth dose table and an isodose curve are related because
Ans✓✓✓ both display the dose at a point on the central axis
accounts for changes in scatter inside the patient as the field size
changes Ans✓✓✓ sp
accounts for the changes in scatter in air as jaw setting changes
Ans✓✓✓ sc
aligning data sets from two or more imaging modalities is called
Ans✓✓✓ image registration
an electron field is to be treated with an 8 cm diameter circle field using
the 10x10 cone at an extended distance of 110 cm to the skin. The
output factor for the field must be Ans✓✓✓ measured with the cutout
in the cone at treatment distance
as PDD increases, depth __ Ans✓✓✓ decreases
as PDD increases, distance __ Ans✓✓✓ increases
as PDD increases, energy __ Ans✓✓✓ increases
, as the number of beams in a plan increases, the conformity __
Ans✓✓✓ increases
as the number of beams in a plan increases, the integral dose ___
Ans✓✓✓ decreases
as TMR decreases, depth __ Ans✓✓✓ increases
as TMR increases, energy __ Ans✓✓✓ increases
beam modifier examples Ans✓✓✓ wedge, bolus, compensator
bilateral lung dose constraint Ans✓✓✓ V20 <35%
bolus Ans✓✓✓ typically a tissue equivalent material used to pull dose
closer to surface
compensator Ans✓✓✓ compensate for missing tissue and create
uniform dose distribution
constraints Ans✓✓✓ maximum dose limits and minimal accepted dose
levels for targets and organs at risk
1 Gy is equal to Ans✓✓✓ -100 rad
-10^2 cGy
-1 J/kg
a conformal beam arrangement will giver a __ dose to a critical
structure than a nonconformal beam arrangement Ans✓✓✓ lower
a correction applied to the %DD to account for extended distance
Ans✓✓✓ mayneord f factor
a decrease in field size yields a __ and increase in __ Ans✓✓✓
decrease in Sc, MU
a field dimension at depth is (smaller, larger, the same) as the field size
on the skin Ans✓✓✓ larger
a non-coplanar beam is defined as Ans✓✓✓ beams with couch angle
a percent depth dose increases in value as Ans✓✓✓ the beam energy
and SSD increase and the depth decreases
,a percent depth dose table and an isodose curve are related because
Ans✓✓✓ both display the dose at a point on the central axis
accounts for changes in scatter inside the patient as the field size
changes Ans✓✓✓ sp
accounts for the changes in scatter in air as jaw setting changes
Ans✓✓✓ sc
aligning data sets from two or more imaging modalities is called
Ans✓✓✓ image registration
an electron field is to be treated with an 8 cm diameter circle field using
the 10x10 cone at an extended distance of 110 cm to the skin. The
output factor for the field must be Ans✓✓✓ measured with the cutout
in the cone at treatment distance
as PDD increases, depth __ Ans✓✓✓ decreases
as PDD increases, distance __ Ans✓✓✓ increases
as PDD increases, energy __ Ans✓✓✓ increases
, as the number of beams in a plan increases, the conformity __
Ans✓✓✓ increases
as the number of beams in a plan increases, the integral dose ___
Ans✓✓✓ decreases
as TMR decreases, depth __ Ans✓✓✓ increases
as TMR increases, energy __ Ans✓✓✓ increases
beam modifier examples Ans✓✓✓ wedge, bolus, compensator
bilateral lung dose constraint Ans✓✓✓ V20 <35%
bolus Ans✓✓✓ typically a tissue equivalent material used to pull dose
closer to surface
compensator Ans✓✓✓ compensate for missing tissue and create
uniform dose distribution
constraints Ans✓✓✓ maximum dose limits and minimal accepted dose
levels for targets and organs at risk
