1
Annual Quality Assurance Summary:
Institution:__________________
1. Mechanical:
i.
Gantry angle readouts vs angle
ii.
Collimator readouts vs angle
iii.
Table readouts
iv
Optical Distance Indicator cal/linearity
v.
Field size readouts
vi.
Collimator isocenter
vii.
Couch isocenter
viii. Gantry isocenter
ix.
Laser alignment
x.
Coincidence of axes
xi.
Couch vertical alignment (80cm-140cm)
xii.
Table top integrity/sag
(1deg)
(1deg)
(2mm;1deg)
(2mm)
(2mm)
(2mm diam)
(2mm diam)
(2mm diam)
(2mm)
(2mm)
(2mm)
(2mm)
2. Radiation
A. Film
i.
Collimator isocenter (upper,lower) and coincidence with
mechanical isocenter
(2mm)
ii.
Couch isocenter and coincidence with mechanical
isocenter
(2mm)
iii.
Gantry isocenter and coincidence with mechanical
isocenter
(2mm)
B. In-Air:
i.
Sc vs field size
ii.
Sc(output) vs gantry angle
iii.
Monitor chamber linearity vs. dose, dose rate and
gantry angle.
iv.
Electron ouput vs. gantry angle
C.: Water Scanning System
I.
Photons
i.
FDD’s vs. field size
ii.
Cross beam profiles
iii.
Diagonal in-air profile for OAR consistency
iv.
Isodose distribution
(2%)
(2%)
(2%)
(2%)
(2%)
(3%)
II.
Electrons
i.
FDD's (25x25) for Rp determination
(2mm)
ii.
Cross beam profiles (dmax) (25x25) for flatness and
symmetry
(3%)
iii.
FDD's (10x10) for d50 determination
D. QA Water Phantom
i.
Sc,p vs. field size (isocentric)
(2%)
2
ii.
iii.
iv.
v.
vi.
Wedge factors/centering (ref depth)
Tray factors (ref depth)
Effective SSD's (electrons)
Electron cone factors
Dose output calibration.
3. Q.A. Instrumentation:
i.
Daily QA phantom(s) cross-calibration
4. Computer
i.
Intercompare isodoses for 10x10 field
(2%)
(2%)
(2cm)
(2%)
(2%)
3
Annual Accelerator QA Tests for Varian ________
Date: ________
1. Mechanical:
i.) Gantry Angle Readouts vs angle
Digital Readout
Mechanical Readout
Bubble Level
Reading
0
90
180
270
initials:_____ date:_______
ii.) Collimator Angle Readouts vs angle. (Gantry at 90 or 270)
Digital Readout
Mechanical Readout
Bubble Level
Reading
0
90
270
initials:_____ date:_______
iii. a) Table Readouts (lateral, vertical, longitudinal)
As a reference condition, set the table surface to 100 cm SSD, laterally centered (0.0
mechanical), longitudinally set to 0.0. Set to mechanical positions, read digital display on
console.
Lateral
Longitudinal
Vertical
Digital MechanDigital
MechanDigital
Mechan

ical (cm)
ical(cm)
ical(cm)
(mm)
(mm)
0.0
0.0
0.0
10.0
15.0
10.0
15.0
30.0
20.0
-10.0
-15.0
-10.0
-15.0
-30.0
-20.0
initials:_____ date:_______
iii. b) Table Readouts (rotation angle)
Digital Readout
Mechanical Readout

(deg)
0.0
90.0
270.0
initials:_____ date:_______

(mm)
4
iv.) Optical Distance Indicator
ODI Reading
Front Pointer
80 cm
90 cm
100 cm
110 cm
120 cm
initials:_____ date:_______
v.) Field Size Readouts
X (dig)
Y (dig)
X x Y (measured)
5x5
10 x 10
15 x 15
20 x 20
30 x 30
40 x 40
initials:_____ date:_______
vi.) Collimator Isocenter
a.) Tape graph paper to table. Set gantry to 0. Mark cross hair center. Rotate collimator,
marking center every 45. Inscribe a circle containing each point on its circumference.
The diameter of that circle should be < 2mm.
Measured diameter: __________ mm
initials:______ date:_______
b.) Determine, graphically, the axis of rotation of the collimators. Adjust all the sagittal
lasers to pass through the center of rotation (isocenter) of the collimator. Using a device
(eg., “wiggler”) to denote the axis of rotation, adjust the vertical wall lasers to coincide
with this axis.
initials:_____ date:________
vii.) Table Isocenter
a.) Using the marked collimator rotation axis, rotate the table through 180, again
marking the location of the cross hairs every 45. Inscribe a circle containing each point
on its circumference. The diameter of that circle should be < 2 mm.
Measured diameter: __________ mm
initials:______ date:_______
b.) Determine, graphically, the axis of rotation of the table. Measure the distance between
it and the collimator axis of rotation. They should be within 2 mm.
Measured spacing: __________ mm
initials:______ date:_______
5
viii.) Gantry Isocenter
a.) Tape one of the front pointers to the end of the table. (Its tip is 2 mm in diameter.)
Using another front pointer (set to 100 cm) or the “wiggler”, attached to the front pointer
assembly, determine the axis of rotation of the gantry (isocenter) as a point contained
within the 2 mm diameter table-mounted front pointer.
Measured diameter: __________ mm
initials:______ date:_______
b.) With the gantry at 0, adjust the horizontal wall lasers to bisect the end of the gantrymounted front pointer.
initials:_____ date:_______
:
ix.) Laser alignment (all within 2 mm)
Right
walls: horizontal_____
vertical _____
sagittal: ____
ceiling: sagittal _____
lateral _____
TBI ______
Left
_____
_____
initials:_____ date:_______
x.) Coincidence of axes
Slide the table under the front pointer (wiggler) and mark its location on a piece of
graph paper and measure the distance to the collimator/table rotation axes. Note that the
sagittal room lasers should be aligned through this axis. All three axes should be
coincident to within 2 mm.
Measured spacing: __________ mm
initials:______ date:_______
xi.) Couch vertical alignment
Using a plum bob, mark a point on the table at the maximum vertical table level. Drop
the table to its minimum height and check with plum alignment. Remove plum bob and
set collimator cross hairs to same point. Run the table through its limits (80-140 cm). The
point on the table should remain within 2 mm.
Measured deviation: __________ mm
initials:______ date:_______
xii.) Table top sag
initials:_____ date:_______
2. Radiation
A. Film
i.) Collimator isocenter.
a.) Upper Jaw.
Tape an XV film to the table at an SSD of 100 cm. Pinprick the center of rotation
of the collimators. Close the upper jaw to 2 mm or less. Lay a polystyrene plate (1-2.5cm
thick) over the film. Expose the film to 20 MU at the following collimator angles: 0,
30, 60, 90, 330, 300 and 280. The diameter of the focal ‘spot’ should be less than 2
mm, centered within 2 mm of the mechanical center.
Spot diameter: _____ mm Distance from pin _____ mm
initials:______ date:_______
6
b.) Repeat (a) for lower jaws.
Spot diameter: _____ mm Distance from pin _____ mm
initials:______ date:_______
ii.) Table isocenter.
Using either the upper or lower jaws, repeat the above exposure sequence for the
same selection of table angles.
Spot diameter: _____ mm Distance from pin _____ mm
initials:______ date:_______
iii.) Gantry isocenter
Tape an XV film to a polystyrene plate (2.5cm). Stand the plate and film on the table
with the film surface coincident with the isocenter and angled about 20 (to be able to
easily see the laser projections on the surface). Pinprick the mechanical isocenter, as
defined by the lasers. Tape a cover plate (1-2.5cm thick) over the film, squeezing out any
air bubbles. Close either the upper or lower jaws and expose the film to 20 monitor units
at each of the following angles: 0, 30, 60, 90, 135, 330, 300, 280 and 225. As
above, determine the center of rotation, diameter of the spot and distance from the
mechanical isocenter.
Spot diameter: _____ mm Distance from pin _____ mm
initials:______ date:______
Isocenter coincidence: collimator, table and gantry mechanical and radiation isocenters
are coincident to within 2mm.
initials:_____ date:______
B. In-Air
i.) SC vs. field size.
Setup and level Farmer chamber at end of treatment table, using lasers to center the
chamber at the isocenter. Select the appropriate buildup cap for the energy and perform
the measurements listed below.
Energy
Chamber
Electrometer
Rate(MU/min)
Field Size
6x6
8x8
10x10
20x20
30x30
40x40
10x101.5m
4x4 1.5m
S/N
Readings
Ave.
Sc
Table
initials:_____ date:_______

7
Energy
Rate(MU/min)
Field Size
6x6
8x8
10x10
20x20
30x30
40x40
10x101.5m
4x4 @1.5m
Readings
Ave.
Sc

Table
initials:_____ date:_______
ii) Output versus Gantry angle, and
iii.) Monitor chamber linearity vs dose rate and gantry angle.
With the chamber positioned on the iso-center axis, and using a 10x10 field size,
perform the following measurements as a function of gantry angle:
Energy:______
Gantry Angle(readings)
Rate
(mu/min)
0
90
270
180
Summary:
Gantry Angle(Relative output)*
Rate
(mu/min)
0
90
270
180
*Record the variation in output, relative to 10x10 at 0 gantry angle and nominal dose
rate (usually 320 MU/min for 2100c or 400MU/min for 2300cd).
Conclusions:__________________________________
initials:______ date:_______
8
Energy:______
Gantry Angle(readings)
Rate
(mu/min)
0
90
270
180
Summary:
Gantry Angle(Relative output)*
Rate
(mu/min)
0
90
270
180
*Record the variation in output, relative to 10x10 at 0 gantry angle and nominal dose
rate (usually 320 MU/min for 2100c or 400MU/min for 2300cd).
Conclusions:__________________________________
initials:______ date:_______
iv.) Electron output vs gantry angle.
For a 10x10 cone, take readings vs gantry angle using the 6MV buildup cap. The 0
gantry readings can be used as the baseline.
Gantry Angle(readings)
Energy
(MeV)
6
9
12
15/16
18/20
22
0
90
270
180
9
Summary:
Gantry Angle(Relative Output)*
Energy
(MeV)
0
90
270
180
6
9
12
15/16
18/20
22
*Record the variation in output, relative to 10x10 at 0 gantry angle and nominal dose
rate (usually 320 MU/min for 2100c or 400MU/min for 2300cd).
Conclusions:__________________________________
initials:______ date:_______
C. Water Scanning System
I. Photons
i.) Fractional Depth dose vs field size.
Scan each energy photon beam for depth dose evaluation.
Energy: _______MV
Measurement/Table/(%)
Field Size
5cm
10cm
5x5
/
/
/
/
10x10
/
/
/
/
20x20
/
/
/
/
35x35
/
/
/
/
Conclusions:__________________________________
20cm
Filename
/
/
/
/
/
/
/
/
initials:______ date:_______
Energy: _______MV
Field Size
5cm
10cm
5x5
/
/
/
/
10x10
/
/
/
/
20x20
/
/
/
/
35x35
/
/
/
/
Conclusions:__________________________________
20cm
Filename
/
/
/
/
/
/
/
/
initials:______ date:_______
ii.) Cross beam profiles. For a 40x40 collimator setting:
Energy: _______MV
flatness
symmetry
dmax:
inplane
crossplane
10 cm:
inplane
crossplane
Conclusions:_________________________________
initials:______ date:_______
10
Energy: _______MV
flatness
dmax:
10 cm:
symmetry
inplane
crossplane
inplane
crossplane
Conclusions:_________________________________
initials:______ date:_______
iii.) Diagonal in-air profile. For a 40x40 collimator setting:
Energy
flatness
symmetry
Conclusions:_________________________________
initials:______ date:_______
iv.) Measure one isodose distribution(each energy) for a 10x10 field for computer
planning system testing.
Energy
Filename
6
18/25
initials:_____ date:_______
II. Electrons
i.) Fractional depth dose (RP).
Using a 25x25 cone, measure and analyze each electron beam. Use, if possible, diodes.
Energy
Rp
Table
(mm)
6
9
12
15/16
18/20
22
initials:_____ date:_______
ii.) Measure cross beam profiles for flatness and symmetry (25x25 field).
In Plane
Cross Plane
Energy
Flatness
Symmetry
Flatness
Symmetry
6
9
12
15/16
18/20
22
initials:_____ date:_______
11
iii.) Fractional depth dose (d50).
Using a 10x10 cone, measure and analyze each electron beam.
Energy
D50
Table
(mm)
6
9
12
15/16
18/20
22
initials:_____ date:_______
D. QA Water Phantom
i.) SC,P vs Field Size.
Set up the Farmer chamber in the standard QA water phantom configuration. Set the
depth to dmax, SSD = 100 cm:
T= _____C
P = _____ mmHg
CT,P = ______
Chamber = PTW S/N______
Electrometer= ________
Bias = _____ High Voltage = _____ Leakage = ________
Energy = ______ MV
Field
Size
Reading
4x4
6x6
8x8
10x10
16x16
20x20
28x28
32x32
40x40
depth = _____ cm
Ave.
SC,P
Table

Table

initials:_____ date:_______
Energy = ______ MV
Field
Size
Reading
4x4
6x6
8x8
10x10
16x16
20x20
28x28
32x32
40x40
depth = _____ cm
Ave.
SC,P
initials:_____ date:_______
12
ii.) Wedge factors.
For a 10x10 field, chamber positioned at 10cm (100 cm SSD), determine wedge factors:
Energy = ________ MV
depth = ______ cm
Upper Wedges (2300cd)
Wedge
Reading
Ave.
WF
Table
15 in
out
30 in
out
45 in
out
60 in
out
Conclusions:__________________________________
initials:______ date:_______
Energy = ________ MV
depth = ______ cm
Lower Wedges (2300cd)
Wedge
Reading
Ave.
WF
Table
15 in
out
30 in
out
45 in
out
60 in
out
Conclusions:__________________________________
initials:______ date:_______
Energy = ________ MV
depth = ______ cm
Upper Wedges (2300cd)
Wedge
Reading
Ave.
WF
Table
15 in
out
30 in
out
45 in
out
60 in
out
Conclusions:__________________________________
initials:______ date:_______



13
Energy = ________ MV
depth = ______ cm
Lower Wedges (2300cd)
Wedge
Reading
Ave.
WF
Table
15 in
out
30 in
out
45 in
out
60 in
out
Conclusions:__________________________________
initials:______ date:_______
iii.) Tray Factors:
Energy = ________ MV
Tray
Reading
1/4”
1/4+1/8”
1/4+1/4”
1/2”
depth = ______ cm
Ave.
Conclusions:__________________________________
Energy = ________ MV
Tray
Reading
1/4”
1/4+1/8”
1/4+1/4”
1/2”
Table

initials:______ date:_______
depth = ______ cm
Ave.
Conclusions:__________________________________
TF

TF
Table
initials:______ date:_______

14
iv.) Effective SSD’s for electrons, and v.) Cone factors
The procedure is to calculate the dose at various extended SSD’s and compare with
measurement. This method is a simple test of effective SSD’s, not a method for
measuring them. Sample different cones and cutouts (either the standard insert or an
arbitrary rectangular cutout) each year.
Energy: 6 MeV
Cone depth
10x10
15x15
20x20
25x25
SSD
100
100
100
100
15x15
110
Measurement
Ave.
Output
Table

Table

Table

Table

initials:_____ date:_______
Energy: 9 MeV
Cone
depth
10x10
15x15
20x20
25x25
SSD
100
100
100
100
20x20
110
Measurement
Ave.
Output
initials:_____ date:_______
Energy: 12 MeV
Cone
depth
10x10
15x15
20x20
25x25
SSD
100
100
100
100
10x10
110
Measurement
Ave.
Output
initials:_____ date:_______
Energy: 15/16 MeV
Cone
depth SSD
10x10
100
15x15
100
20x20
100
25x25
100
15x15
Measurement
Ave.
Output
110
initials:_____ date:_______
15
Energy: 18/20 MeV
Cone
depth SSD
10x10
100
15x15
100
20x20
100
25x25
100
20x20
Measurement
Ave.
Output
Table

Table

110
initials:_____ date:_______
Energy: 22 MeV
Cone
depth
10x10
15x15
20x20
25x25
SSD
100
100
100
100
25x25
110
Measurement
Ave.
Output
initials:_____ date:_______
vi.) Check output calibration using standard protocol. Protocol__________.
Location of measurement (logbook): ___________ initials:______ date:_______
3. QA Instrumentation
Using output factor determination from (2. iv.), above, check calibration of daily QA
instrument. Record logbook and page.
Logbook: ______ page: ______
initials:______ date:_______
4. Computer Planning Systems
Use measured isodose scans to compare against each planning system.
Planning System
Field Size
Comments
initials:_____ date:_______
Annual Quality Assurance Complete:
Signature: ___________________
Date: __________