Daily Treatment Machine Quality Assurance (QA):

Procedures:

Dustin, Erin, Faleesa

Varian Clinic Turn On Procedure:

1. Enter the treatment room and open the door of the Clinac stand assy. Verify that the water temperature is 40 degrees Celsius, water pressure is 70 pounds per square inch (PSI) or above and no warning lights are on, such as add water or sulfur hexafluoride (SF6) gas pressure.
2. You should also hear the machine "running". If all of the above parameters are OK, then proceed to step 2, if not then page the system specialist. Rotate the gantry and collimator to 0 degrees.
3. Turn on the four dimensional treatment console (4DTC), on-board imager (OBI) and reconstructor computer, monitors, as well as the Clinac treatment monitor. Open the front door on the Clinac control console and turn the key from standby to on (1/4 turn clockwise), after turning the key, the interlock "KFIL" should disappear from the Clinac treatment monitor and you should see the words "time delay" and a clock counting down from 12 minutes next to it.
4. OBI computer will come up with LOG ON screen.
5. Now connected to Treat Trilogy will show on bottom toolbar and the mouse should move between both screens.
6. Move mouse to 4DTC screen and press "Ctrl_Alt_Backspace" and enter password.
7. After Hyper Terminal is displayed, Turn ON multi-leaf collimator (MLC) power supply. This should launch a series of text messages across the hyper-terminal window on the 4DTC and will start the MLC "checkout". This "checkout" will take approximately 7-9 minutes to complete and the text will pause on the MLC monitor several times during the "checkout" for up to 30 seconds. When the MLC monitor says "ready" at the bottom, minimize the "hyperterminal" screen and launch the "Treatment" application. When the "Treatment" application loads select "standby" and this should satisfy the record and verify interlocks on the Clinac and allow you to run beam.
8. Go to the "Clinac" control keyboard and select "Morning Checkout" scroll through the pages until you can select 18 megavolts (MV) 400 monitor units (MU) prescription and select it. The machine should mode up and present and interlock sub-screen on the Clinac monitor. If you see the interlock "RVBP", go to the 4DTC and verify that you have selected "standby". You should now be able to run the 18 MV 400 MU warm-up beam (select and run it twice before running a 6MV beam), followed by the 6MV 400 MU warm-up beam. After completing these two warm-up beams, get out of the "Morning Checkout" by pressing F1 and answering the questions and following the on screen prompts.
9. If you are warming up the machine on a normal treatment day, you should then launch the Argus program and perform the ''daily monitor unit test", as well as the other assigned tests in Argus before treating any patients. At my facility, all of the required beams for the daily QA have a prescription preloaded in ARIA under the prescription name "morning QA" and the associated day (i.e. morning QA Monday, Morning QA Tuesday, etc.). Turn on the KV X-ray generator via the OBI dedicated keyboard switch.
10. Warmup the KV imager by launching the OBI application on the OBI computer and following the onscreen instructions.

Daily MU test in Argus QA:

• After warming up the machine as described in the Varian Clinac turn-on procedure, you will need to setup the correct Daily QA check device for your associated machine in the room (QA scanners cannot be shared. In the event that a scanner is sent out for repairs, physics must perform daily QA).
• Place the daily QA device in the room and connect the round serial cable to the back of the unit.
• Orient the Daily QA device in the 20x20 Iight-field with the top of the scanner at 100 centimeters (cm) with the "build-up" acrylic plate removed from the scanner and match the light field to the outer 20x20 field lines marked on top of the scanner. Note: The cross hair of the Daily QA device may not exactly match the crosshair of the light field. The scanner should always be oriented so that the serial cable comes out of the scanner towards the back of the Clinac or its stand. All fields are checked with a 20x20 field or a 20x20 electron cone, with the exception of the stereotactic radiosurgery (SRS) 6 MV beam on the Trilogy; it is a 15x15 field. The prescription in ARIA is preset for these field sizes.
• Put the "build-up" material back on top of the scanner before running any photon beams and be sure and remove it prior to running any electron beams.
• Open the Argus program at the correct computer terminal and login to the system using your already assigned username and password for Argus.
• Select the appropriate machine that you are going to QA and then select the appropriate day for the day that you are running the QA (i.e. Monday, Tuesday, etc), then select the Daily Monitor unit test and the beam that you wish to QA, then double click/open field/monitor. This will launch a window to the right hand side of the monitor giving a description of the test that you will be running (i.e. energy, enhanced dynamic wedge or not and what angle, accessories, etc.)
• In the top left hand comer of the new window that launched in the previous step you have the option to "average" or "download", you will select download. After you select download, you will see that a sub-program, the daily QA check software will launch in the background, but you should not have to interact with this program until the end of the QA. Have appropriate beam ready to run in ARIA/ARGUS (ready to run moded up). Once all of the temperature and pressure readings are done, you will see the message "receiving data" on the foremost window (the message takes approximately 1 minute to come up on the first run of the day and immediate on subsequent runs, after the temp/pressure is established). You will then run the beam associated with the daily monitor test that you have selected. For subsequent beams, before downloading and proceeding in Argus, check ARIA to make sure the collimator is open and ready to run the next beam of the next field.
• After the beam has completed, the message "receiving data" will change to finished receiving data. You will then have to select "record", then "save" and then "close" before you can select the next be am to be tested. Must do this for all beams regardless of whether they passed. If a beam does not pass you will make a note on the daily QA binder log.
• You will repeat this process until all readings scheduled for that day have been completed.You can then enter the vault and remove the Daily QA check device and restore the serial cable to its original location.
  • Remove Lucite tray for photons
  • Ready to run 6 mega-electron volts (MeV) and 9 MeV beams, so insert the 20x20 applicator with insert and check that field size matches the tray field size.
  • Repeat for 9 MeV; unplug daily QA scanner after selecting daily QA check-2 software and close the program.

• Complete the Varian linear accelerator daily report log. If all beams pass (green), check the appropriate box and make sure the date and therapist initials are recorded. If any test fails (red), make note of the modality (photons, SRS photons, or electrons), energy (4, 6, 10, or 18 MV photons, or 6, 9, 12, 16, or 20 MeV electrons) and EDW value (10-60 degrees). Notify the physicist responsible for this machine before proceeding with treatment. If you have a beam that is yellow during QA, record as a problem so that physics can investigate. You may proceed with treatment on a yellow beam. A physicist will follow up daily and sign the daily log report.
• Audio and visual equipment must be working properly during all treatments.
• ODI check - slide ODI pointer into front pointer assembly. Adjust pointer to 100 mark. Raise table height to 100 source to skin distance (SSD). Pointer should read 100 when table is at 100 SSD. Remove ODI pointer and shadow tray assembly.
• Field size check - collimator setting should be set at 20x20 cm. With table at 100 SSD check field size with a ruler to ensure that the field size is 20 cm x 20 cm.
• Laser QA - Align central axis (CAX) of laser cube in the CAX of the field. Raise table until you have 100 SSD at the CAX of the laser cube. Side laser should be in alignment with the marks on the laser cube. Rotate gantry to both 90 and 270. Make sure that overhead laser is in alignment with the laser cube, and then make sure that the CAX of the field is in alignment with the laser cube.
• While the gantry is at 90 and 270, check the back pointer. Back pointer should be in perfect alignment with the anterior to posterior mark on the laser cube.
• Door check - close door to treatment room. At the treatment console while you are in machine morning check out, select enter. Turn key and beam on. Interrupt beam by opening the door. Beam should stop. Close door, hit enter on treatment console and finish beam.
• OBI QA is performed once a week. Turn on OBI generator as well as the OBI console. You need the Lucite cube with wire tape. Table is at 100 SSD. Gantry is at 0 degrees. Place Lucite cube so that CAX on the cube is in alignment with the field size CAX, side marks on cube should be in alignment with side lasers. Make note of long position and pull table out of OBI range for 20 seconds tube warmup. Leave room and close door. Download axes on OBI workstation and bring the arms to position using OBI/AUTO. 20-second warm-up box will pop up. Step on foot switch and hold for 20 seconds. Login to ARIA. Select Daily QA, OBI. Must be scheduled in Time Planner to bring up. Remotely move table back to original setup longitudinal position by hitting F2 on Clinac console and manually typing number in and assisting. Mode up on right lateral. You will be prompted to assist gantry (if you are not prompted, call a physicist). Assist gantry. Need to watch monitor to see that gantry is moving. When field parameters match, beam on to take right lateral image. Go to OBI console, at the bottom right select2D/2Dmatch. You will automatically be prompted by the machine to assist the gantry to the AP position. Beam on for AP image. OBI console bottom right comer, select analyze. AP and lateral images are side by side. Click on either image and enlarge. At OBI console using ARIA tools select green crosshairs. This will project on image. From ARIA tools, select ruler tab. Click on center of green crosshairs while holding on to the mouse drag to image CAX. On AP image, you will be taking two measurements. One from left to right, one from superior to inferior. Minimize AP image and bring up lateral image. With ruler, take an anterior to posterior measurement and superior to inferior measurement.
• Readings from these measurements are documented in the OBI QA log book. Minimize lateral image and maximize AP image. From the ARIA tools, select the match images button. Click on green crosshairs and drag to overlap the CAX crosshairs. Minimize AP image and maximize lateral image. Using arrow keys on the keyboard, move so that you align anterior to posterior mark with CAX. It is important that you do not touch the mouse while making any adjustments with the lateral image. Any movement made at this point with the mouse will move your AP. At the bottom of the screen you will have readings for the vertical, lateral, and longitudinal shifts. These readings need to be recorded in the OBI QA log book. On the bottom right of the OBI console, select the apply shifts button. This will prompt you to assist the table. Assist table using motion enable button. Watch that the table moved, select done. Go into room and check that lasers are aligned to wire tape on Lucite cube. Any deviation of lasers to wire in the vertical, lateral or longitudinal directions should be recorded in OBI log book. Any deviations greater than what is physics has recorded in the OBI QA log book should be reported to physics immediately before proceeding with any patient treatments.
• Login in Argus and record findings for ODI, field size, lasers, and door check.
• Physics will be responsible to sign the QA log for each machine every day. When problems have been addressed, physics must sign the daily log book and put the information in ARGUS.
• You may not proceed with treatment should any beam data, ODI, field size, lasers, or door check, fail QA. Call a physicist immediately.
• The physicist is responsible for releasing the machine for treatment.

Siemen's Daily Linear Accelerator QA:

Procedures:

• Turn on Syngo workstation
• Linear Accelerator in set on a timer and goes on automatically - but the ON key must still be turned
• Motion stop is activated, so this must be cleared
• Hit 24 volt reset button
• Rotate the gantry to 0 degrees
• Check H2O hoses to be sure nothing is leaking

Safety QA:

• Door interlock - start running beam, then open the door to be sure beam turns off
• Check beam on light
• Verify audiovisuals are both working

Dosimetric QA:

• Run 15 MV photons for 500 MU to warm up
• After running 500 MU, align Standard Imaging BeamChecker Plus (see images & link) to lasers at 100 SSD
  • Run 6 MV = 100 MU
  • Run 15 MV = 100 MU
  • Run all electron energies = 100 MU each
• Record all output constancy values in warmup binder - **If any are out of tolerance, it will warn you with a beeping noise and the value will flash. You must go in the treatment room and clear it before proceeding. Physics is informed if this happens.

• Download warmup patient in QA mode in V&R
  • In treatment room, initialize flat panel by extending it to 145
  • Insert the x-retic tray
  • Kick table to 90 degrees so table it out of the way of the flat panel for the daily QA
  • Run the QA - this will take an image of the crosshairs in the gantry and compare it to the crosshairs on the x-retic tray that is inserted into the gantry
  • The image will state whether it has passed or failed
  • We document the lateral, longitudinal, and rotational differences between the two

Geometric QA:

• Verify the laser alignment to the beam checker
• Check the optical distance indicator (ODI) compared to the mechanical front pointer
• Insert the MLC tray and be sure there are no gaps between leaves with the tray and the downloaded field

Types of Equipment:

Standard Imaging BeamChecker Plus - http://www.standardimaging.com/product_home.php?id=13

Tolerances (expected):

Dosimetry:1

• X-ray output constancy - 3%
• Electron output constancy - 3%

Mechanical:

• Laser localization alignment - 2mm
• Optical distance indicator - 2mm
• Collimator size indicator - 2mm

Safety:

• Door interlock - Functional
• Audiovisual Monitors - Functional
• Beam on indicator - Functional

Imaging:

• Collision interlocks - Functional
• Positioning/repositioning -
  • Planar kV & MV (EPID) Imaging - < 2mm
  • Conebeam (kV & MV) - <1mm
  • Imaging and treatment coordinate coincidence - <2mm

Procedure / Tolerances
Daily quality assurance (QA) on a linear accelerator requires some basic steps before suggested specifications can be tested. First, on a Varian Clinac 2100C, the key must be turned to the on position. The Gantry is then turned to the upright 180o or straight down 0o location and temperature and pressures are checked. The temperature should read 40o, the gas should read 35 psi, and the pump pressure reading should be 80 psi. If any of the temperature or pressures are off the desired values QA is placed on hold and an engineer is contacted. After turning on the 4DTC computer, the multileaf collimation system (MLC) is turned on. Upon completion of testing all 60 MLC, the daily Linac QA may start.
21st Century Oncology Linear Accelerator Daily QA consists of four separate types of tolerance checks such as safety checks, mechanical alignment, imaging, and output tests.2
Safety checks:
a) Door interlock
b) Door functioning properly
c) Audiovisual communication devices
d) Radiation warning light-signs & beam on
e) Radiation warning monitor
f) Electron cones auto field size
All safety checks are a pass or fail technique.
Mechanical alignment:
a) ODI isocenter distance SAD +/- 1mm
b) Laser alignment <2mm
c) Light field vs. digital readout+/- 2mm
d) MLC continuous strips
Imaging:
a) MV EPID collision test
b) SID verification 5mm
c) CAX alignment +/- 2mm
d) Positioning / re-positioning +/- 2mm
Output test: a) Photons +/- 3-5%
b) Electrons +/- 3-5%

Types of equipment
Varian Clinac 2100C
Standard Imaging QA Beam Checker Plus
Nuclear Associates Teletherapy Align Gauge
Graph paper
Images


References
1. Khan FM. The Physics of Radiation Therapy. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2010(398).
2.Kutcher G, Coia L, Gillin M, et al. Comprehensive qa for radiation oncology. Med Phys. 1994;21(4):587-592.

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Monthly Treatment Machine QA:

Brandon and Bret

Procedures:

I. General Condition and Safety

• Check for Radiation Warning Sign
• Check Door operability and Interlock
• Check Key Switch Interlock
• Check Audio Visual Communication
• Make sure Warning Light on when Beam on
• Make sure Machine movements with pendant work
• Check Beam Monitoring System (BMS)
  • Check that Primary/Secondary MUs are consistent
  • Check that Accumulated MU displayed are accurate
  • Make sure BMS terminated at preset MU
  • Review that BMS will not operate until recycled

II. Dosimetry

• Review Linac Daily QA records
• Check the X-ray Output constancy @ 600 MU per minute
• Check the X-ray Output constancy @ IMRT dose rate
• Check the Electron Output constancy
• Check the Photon Beam Profile Constancy
• Check the Electron Beam Profile Constancy
• Check the Electron Beam Energy Constancy
• Check the Light and Radiation Field coincidence for a symmetric field
• Check the Light and Radiation Field coincidence for an asymmetric field
• Check the Enhanced Dynamic Wedge (EDW) Photon Output Constancy
• Check the Gating Photon Output Constancy

III. Portal Imager and MLC

• Check that portal image of a phantom matches the correct pattern and shape
• Check that the field edges of a static MLC pattern match on graph paper
• Check that the picket fence pattern is uniform without leaf deviations

IV. Mechanical Tests

• Check the gantry rotation by comparing the digital indicator with a level
• Check the collimator rotation by comparing the digital indicator with a crosshair walkout
• Check the light field and field size indicator by comparing the digital jaw readout and measuring the field size
• Check the SSD by comparing the ODI to a pointer
• Check each individual laser to assure it is at isocenter
• Check the couch position indicator by comparing the digital readout to a measured value
• Check the wedge and Accessory accuracy and latching
  • Check the wedge placement accuracy
  • Check the BB Tray placement accuracy
  • Check for correct latching of the wedges
  • Check for correct latching of the block tray

Types of Equipment (provide links when possible):

• True Beam Linear Accelerator
• IsoCal Phantom (lasers)
• IsoAlign Jig
• Graph Paper (determine collimator/table walk out from CAX)
• Level (determine four gantry angles are within tolerance: 90,180,270,0)
• Radiochromic Film (determine the match between light field and radiation field)
• Standard Imaging QA Beam Checker Plus (determine output measures)
• Electrometer and farmer chambers (also determine output check)

Tolerances (expected): The Dosimetry and Mechanical sections have tests that must be within tolerance.

Dosimetry1

Test Performed	Tolerance
X-ray Output Constancy @ 600 MU/min	2%
X-ray Output Constancy @IMRT dose rate	2%
Electron Output Constancy	2%
Photon Beam Profile Constancy	2%
Electron Beam Profile Constancy	3%
Electron Beam Energy Constancy	2%/2mm
Light/Radiation Field coincidence (Symmetric)	2mm
Light/Radiation Field coincidence (Asymmetric)	1mm
EDW Photon Output Constancy	2%
Gating Photon Output Constancy	2%

Mechanical1

Test Performed	Tolerance
Gantry Rotation	1 degree
Collimator Rotation	1 deg/1mm
Light Field/Field Size Indicator	2mm
SSD	1mm
Lasers	1mm
Couch Position Indicators	1deg/2mm
Wedge Placement Accuracy	2mm
BB Tray Accuracy	2mm

Images:

IsoCal phantom: this phantom attaches to the head of the gantry table to ensure the lasers are accurate from month to month.


Iso Align (jig): the jig is a device that ensure the light field of the gantry coincides with the lasers of the treatment vault. The jig is set at virtual isocenter (100 SSD) and then centered to the crosshairs of the light field, the jig is then rotated 90 degrees to ensure the lasers are accurate.

Gantry, Collimator, Table rotation QA: this simple piece of graph paper is used to ensure the laser "walk out" or deviation from virtual isocenter is less then 2 millimeters (mm). The table and collimator are rotated 90 degrees in either direction to perform the test.

QA Gantry rotation: this is a simple test that uses a level to ensure rotation of the machine is accurate. The gantry is rotated to the four cardinal angles (0,90,180,270). The read out of the level should be accurate within one degree of machine readout.

QA light field and radiation field: this is radiochromic film that is able to display an image instantaneously. This field is used to ensure the light field from the collimator jaws is the same as the area encompassed by the radiation field. The test is done by marking the corners of the light field on the film, then the film is exposed by irradiating it. The two should coincide with one another within 2 mm.

References:

1. Khan FM. The Physics of Radiation Therapy. 4th ed. Baltimore, MD: Lippincott Williams and Wilkins; 2010.

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IMRT QA:

Nick and Jenn

Procedures:

1. After the plan has been approved the physicist completes the IMRT QA. This can be done by completing each beam separately or as a total plan. While most physicists do the plan summation, if the dose is unusually high as in the case of SBRT, the beams will be QA’d and analyzed separately.
2. Phantom or verification plan is created in the TPS. The plan is then transferred to the MapCheck and the linear accelerator.
3. The MapCheck phantom is setup in the treatment room. It is connected with a power/data cable. The phantom is then aligned with the treatment room lasers, and set at the calibrated SSD. (Some centers require a bolus equivalent block resting on top of the MapCheck).
4. Once the QA device is hooked up, you are ready to open Sun Nuclear Corporation Patient icon. (SNC patient- QA computer program)
5. As soon as it is turned on the device immediately measures for background radiation.
6. Pick the patient you are intrested in running a QA plan on and then mode up that patient at the console. The QA IMRT plans are performed using isocentric setup. Each field is set to deliver the dose with the beam perpendicular to the phantom from a gantry
angle of 180 (AP).
7. Run the entire plan. At this point pay close attention to MLC leaves and make sure everything is moving correctly. When the IMRT plan is complete the doses are recorded.
8. The computer analyzes the doses. They are compared with absolute dose and relative dose.
9. If the doses are within the tolerances listed below the patient is approved for treatment.

Types of Equipment (provide links when possible):

• Sun Nuclear Map Check

http://www.sunnuclear.com/documents/MapCHECK2-3DVH.pdf

Tolerances (expected): % difference +/- 3% and Distance= 3mm

Images:

IMRT background radiation reading



Relative dose commissioning



Absolute dose commissioning



IMRT QA phantom


Sun Nuclear Map Check





Sun Nuclear Map Check

References:

1. Sun Nuclear Corporation Web site. http://www.sunnuclear.com/home.asp. Accessed October 2, 2013.
2. IMRT QA II. The American Association of Physicists in Medicine Web site. http://www.aapm.org/meetings/05AM/pdf/18-2601-49028-323.pdf. Accessed October 2, 2013.

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Conventional Simulator QA:

Becky Holly Dustin

Procedures:

Types of Equipment (provide links when possible):

Nucletron Simplicity Oncentra Simulator

http://www.nucletron.com/en/ProductsAndSolutions/Pages/SimulixEvolution.aspx


Varian Acuity
http://www.varian.com/us/oncology/radiation_oncology/acuity/

LEEDS phantom TOR 18FG - QA equipment used for fluoroscopy and fluorography. It provides check of imaging performance. After an initial grey-scale check, image quality is measured by counting the number of details detected and the number of bar-patterns resolved in the image. A record of these numbers will reveal any trend towards deterioration in imaging performance. The LEEDS product checks the resolution limit (0.5 to 5.0 LP/mm), low-contrast large-detail detectability (18 details, 8mm diameter), and circular geometry (lead circle). See website below.
http://www.leedstestobjects.com/index.php?module_name=products/product_setup&product_name=TOR%2018FG&group_name=Fluoroscopy

Tolerances (expected):

Testing of simulators can be divided into 2 parts: 2

• Checking the geometric and special accuracies

• Performance evaluation of the x-ray generator and the associated imaging system

The following are tolerances recommended by the British Institute of Radiology (BIR):2
Illumination of Light Field indication-
1. Average illuminance at the normal treatment distance	40 lux
Reproducibility
2. The difference between the maximum and minimum x-ray field size for repeated settings of the same numerical field indication	1mm
3. The maximum distance between any light field edge and x-ray field edge for repeated settings of the same numerical field indication	1mm
Numerical Indication of field size
4. The maximum difference in mm or percentage of field dimension between the numerical field indication and the dimensions of the x-ray field at the normal treatment distance
5cm x 5cm to 2cm x 20 cm	2mm
>20cm x 20cm	1%
Light Field Indication
5. The maximum distance along the major axis in mm or percentage of field dimensions between the light beam edge and the x-ray field edge at the normal treatment distance
5cm x 5cm to 2cm x 20 cm 1mm	1mm
>20cm x 20cm	0.50%
6. The maximum distance along the major axis between the light beam edge and the x-ray field edge at 1.5 times the normal treatment distance
5cm x 5cm to 2cm x 20 cm	2mm
>20cm x 20cm	1%
7. The maximum distance between the centers of the x-ray field and the light field at the normal treatment distance	1mm
8. The maximum distance between the centers of the x-ray field and the light field at 1.5 times the normal treatment distance	2mm
Geometry of Field Delineators
9. The maximum deviation from parallelity of opposing edges	0.5 degrees
10. The maximum deviation from orthogonality of adjacent edges	0.5 degrees
Indication of X-ray Beam Axis
11. Maximum deviation of the indication of the radiation beam axis from the radiation beam axis over -25cm from the normal treatment distance (NTD) or the working range of the indicator, beam entry	1mm
12. Over NTD to NTD +50cm or working range, exit beam	2mm
Displacement of the X-ray Beam Axis from the Isocenter
13. Maximum displacement of the x-ray beam axis from the radiation isocenter	1mm
Indication of the Isocenter
14. Maximum displacement from the radiation isocenter of any device mounted on the machine for indicating the position of the isocenter	1mm
Indication of the Distance Along the X-ray Beam Axis
15. Maximum difference between the indicated distance and the actual distance from isocenter	1mm
16. Maximum difference between the indicated distance and the actual distance from the x-ray target	2mm
17. Maximum difference between the indicated distance and the actual distance between the isocenter and the image plane	2mm
Zero Position of Rotational Scales- maximum difference between the zero position indicated by the rotational scale and the intended zero position
18. Rotation of gantry	0.5 degrees
19. Rotation of diaphragm housing	0.5 degrees
20. Isocenter rotation of the table	0.5 degrees
21. Rotation of the tabletop	0.5 degrees
22. Pitch of the table	0.5 degrees
23. Roll of the table	0.5 degrees
Opposing Fields
24. Maximum angular deviation between axes of opposed x-ray fields	1 degree
Movements of the Patient Table
25. Maximum horizontal displacement of the table for a change in height of 20cm when loaded with 30 kg distributed over 1 m and when loaded with 135 kg distributed over 2 m, both weights acting through the isocenter	2mm
26. Maximum displacement of the axis of isocenter rotation of the table from the radiation isocenter	1mm
Parallelism of the Table Rotation Axis
27. Maximum angle between the isocenter rotation of the table and the axis of rotation of the tabletop	0.5 degrees
Longitudinal Rigidity of the Table
28. Maximum difference in the table height near the isocenter between 30-kg-load retracted position and 135-kg-load extended position	5mm
Lateral Rigidity of the Table (a)
29. Maximum angle of lateral tilt from horizontal of the plane of the tabletop	0.5 degrees
Lateral Rigidity of the Table (b)
30. Maximum deviation of the height of the table as the table is laterally displaced	5mm
X-ray Tube
31. Maximum focal spot size for at least one focal spot	0.3mm x 0.3mm
32. Maximum shift of image at the isocenter for change of focal spot	0.5mm

Images:

Dustin

The two images above show front pointers that measure the target to axis distance (TAD) at 100 cm.

The image above is graph paper used to compare measurements for the field versus the digital readout.

The two images above show the LEEDS phantom TOR 18FG to test low contrast and spatial resolution.

References:

1. Nucletron Simulator. Nucletron Web site. http://www.nucletron.com/en/ProductsAndSolutions/Pages/SimulixEvolution.aspx
2013. Accessed September 25, 2013.

2. Khan FM. The Physics of Radiation Therapy. 4th ed. Philadelphia, PA: Lippincott, Williams and Wilkins; 2010.

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Treatment Planning System QA:

Amanuel, Lindsey

Procedures:

There are 3 component of treatment planning system (TPS) quality assurance (QA); Acceptance testing, commissioning, and periodic QA
Acceptance Testing:1 performed after installation and before clinical use
- Assures that the TPS performs according to its specification, which includes hardware, software, and Benchmark test
- The QA procedure mainly covers the CT input, anatomical description, beam description, dose calculations, dose display (DVH), and hardcopy output
Commissioning:1 performed before clinical use
- Tests the precision of dose calculation algorithms and system functions
- Tests include dosimetric and non-dosimetric measurements

• Dosimetric tests: measurements, data input, algorithm calculations, dosimetric comparison and verification, external beam calculation verification, absolute dose output and plan normalization, and clinical verifications.
• Non-dosimetric: patient positioning and immobilization, image acquisition, anatomical description, beams, operational aspects of dose calculation, plan evaluation, hardcopy output, and plan implementation and verification

- Commissioning tests can be used as reference for periodic QAs
Periodic QA:1 performed routinely to assure quality consistency of the TPS
- Type of tests vary among clinics

Frequency	Item
Daily	ü Error logs ü Hardware/software change logs
Weekly	ü Digitizer ü Hardcopy output ü Computer files ü Review clinical treatment planning
Monthly	ü CT data input ü Problem review ü Review Hardware, software, and data files
Annual	ü Dose calculations ü Review digitizer, CT/MRI input, printers, etc. ü Review BEV/DRR accuracy, CT geometry., density conversions, DVH calculations, data files, and critical data
Variable	ü Recommissioning due to machine changes or software upgrade

Digitizer Accuracy:2
- Enter simple geometrical figures (square, rectangle, circle…) via digitizer
- Print the figures
- Compare the input and output figures
- Assess the accuracy of input-output devices accessed

CT data:2,3
- Scan a phantom with a well known outer contours and with known electron densities
- Enter the data in the TPS
- Compare geometries and electron densities with the actual data
- Furthermore, routinely review CT number accuracy, image uniformity, slice thickness, and accuracy

Area and volumetric accuracy:2,3
- Scan phantom with well defined dimensions
- Transfer data to TPS
- Verify the accuracy of structure margins
- Verify accurate determination of DVH

Monitor unit (MU) calculation:2,3
- Compare MUs fromthe TPS with the MU check software and hand calculations for

• Off axis square field
• Off axis elongated field
• Wedge off axis field
• Off plane field

Standard treatment techniques:2,3
- Check dose distribution for standard treatment techniques used in the clinic. This may include: head and neck, lung, breast, and pelvis 3DCRTs

Types of Equipment (provide links when possible):

- Eclipse TPS - http://www.varian.com/us/oncology/radiation_oncology/eclipse/
- Pinnacle TPS - http://www.healthcare.philips.com/main/products/ros/products/pinnacle3/
- Radcalc - http://www.lifelinesoftware.com/index.php/radcalc/radcalc-home
- MuCheck - http://mucheck.com/odsweb/
- Quasar body phantom - http://www.osl.uk.com/rte.asp?id=241
- Electron density phantom - http://www.cirsinc.com/products/all/24/electron-density-phantom/

Tolerances (expected):

- Tolerances are site specific

Images:

Image of an electron density phantom used to test accuracy of CT data transfer

Image of a Quasar body phantom used to test area and volumetric accuracy

Image showing axial CT slice of a Quasar body phantom

Image showing DVH determination on a Quasar phantom

Eclipse QA Sample Form:

References:

1. Merrill R, Miller M. Treatment planning system quality assurance. American Association of Medical Dosimetrists Web site. http://medicaldosimetry.org/meetings/2012Presentations/061012/Merrill.pdf. Accessed Sep. 26, 2013.
2. Able CM. Treatment planning system QA in the era of image guided radiotherapy. Able Medical Physics Web site. http://www.ablemedicalphysics.com/uploads/TPS_QA_in_the_Era_of_IGRT.pdf. Accessed Sep. 26, 2013.
3. Mijinheer B, Olszewska A, Fiorino C, et al. Quality assurance of treatment planning systems: practical examples for non-IMRT photon beams. 1st ed. Brussels, Belgium: ESTRO; 2004.