Blue+Group+QA

Daily Treatment Machine QA:
Daily QA on medical linear accelerators are necessary and critical to provide optimal level of care for the patients. The treatment machine’s functional performances must be evaluated periodically, including daily, to ensure its geometric and dosimetric accuracy. Any deviations in the results of the QA can lead to serious effects or injury to the patients.3

For the Daily QA of the treatment machine, recommended by AAMP, the dose output constancy, mechanical accuracy, and safety should be checked. Any deviations in these parameters can influence the accuracy of geometric and dosimetric dose given to the patients.3

=**Procedure:**=
 * Mechanical **
 * Place laser alignment box
 * Align the box to the cross hair of the lasers
 * Check the alignments of lasers to the box
 * Check optical distance indicator ( ODI )

Photon Beam Output Check
 * Dosimetry **
 * Place Daily QA3 on the top of the table and then align the center of Daily QA3 to the CAX.
 * Set the SSD to 100cm to top of Daily QA 3.
 * Set the field size to 20x20 and check/verify light field on the top of Daily QA3.Start the Daily QA3 Software.
 * Set the beam on the machine and check its output for all of the energy used.

Electron Beam Output Check
 * Place Daily QA3 on the top of the table and then align the center of Daily QA3 to the CAX.
 * Place electron cone adapter and 20x20 electron cone.
 * Set SSD to 100cm to top of Daily QA 3.
 * Verify light field on the top of Daily QA3.
 * Start the Daily QA3 Software.
 * Beam on the machine and check its output for all of the energy used.

Door interlock
 * Safety **
 * While the beam is on, open the door to check if the beam is stopped
 * Then, beam on to double check the door interlock

Audiovisual Monitor
 * Make sure both the intercome and video monitoring system are functional


 * Other Safety and Mechanical checks [1] **


 * Verify “BEAM ON” lights Work - turn the Beam on and check the light
 * Verify EDW Orientation
 * Verify Water Level/ Pressure Level/ Temperature/ Gas level - within optimal level
 * Battery Check (Modulator Room)- This is done to verify in case of a power outage or surge.
 * Ladder Status (Modulator Room) – ladder check must be conducted incase of an emergency and we need to get into the treatment planning room and the door does not open.

=**Types of equipment (provide links to websites if desired):**=


 * Sun Nuclear Daily QA3 Hardware
 * []
 * Laser Alignment Tool
 * Ladder
 * Pressure gauge
 * Thermometer

=**Tolerances (expected):**= **Dosimetry**
 * Photon Beam Output Constancy - within 3%
 * Electron Beam Output Constancy - within 3%


 * Mechanical **
 * Localizing Lasers - within 2mm
 * Optical distance indicator ( ODI ) - within 2mm


 * Safety**
 * Door Interlock - functional
 * Audiovisual monitor - functional

=**Images:**=





=**References**=
 * < # Daily QA. Loyola University Medical Center. September 2005.
 * 1) Daily QA. Minneapolis VA, Minneapolis, MN. October 2012.
 * 2) Kutcher GJ, Coia L, Gillin M, et al. //Comprehensive QA for radiation oncology: Report of AAPM Radiation Therapy Committee Task Group 40//. College Park, MD: American Association of Physicists in Medicine; 1994. ||

P** rocedures: **

 * Collimator runout test and field size check on a piece of paper. We measure the actual field size with what is being displayed digitally in both the x and y axis at 10x10, 15x15, and 20x20.
 * The collimator runout test is done by marking all three field sizes on a piece of paper at the axis points then rotating the collimator to 90 and 270 checking those same three field sizes. Our test revealed a .2mm difference.

**Tolerance:**

 * The field size has to be within 2mm, if it falls out of tolerance then the engineer is required to make it correct.[1]





**Procedure:**

 * The optic distance indicator (ODI) reading was verified by measuring it against mechanical pointers of known lengths looking at distances of 80, 90, 100, 110, and 120 SSD.

**Tolerance:**

 * The ODI has to be within +-2mm tolerance.[1]



**Procedure:**

 * The laser alignment using a phantom specially used to align lasers. We set the top to 100 SSD and made sure all lasers intersect the axis in all directions and we moved the gantry to check the ceiling lasers. Then we rotated the gantry to 90 degrees and checked the back pointers to make sure they were aligned properly.

**Tolerance:**

 * All laser tolerances are +-2 mm.[1]



**Procedure:**

 * Mechanical and digital readings on the collimator and gantry. First we positioned a magnetic level on the collimator head until it was level. Once the level was set correctly we recorded the digital and mechanical read outs for those positions of the gantry in 4 orientations; 0, 90, 180, and 270 degrees.

**Tolerance:**

 * The tolerances for the mechanical and digital readings are +/-1 degree.[1]

**Procedure:**

 * Gantry, collimator, couch rotation full 360 degrees rotation.

**Tolerance:**

 * Tolerances are 2mm. [1]





**Procedure**:

 * Using MapCheck we did QA checks for the field symmetry and flatness. Photon and Electon beams were measured.

**Tolerance**:

 * The tolerances for photon beam are flatness 3.0% and 2.0% for symmetry. Electron Beam tolerances are 3.0% for flatness and symmetry.


 * Picture 8**. Flatness and Symmetry for 6 MV


 * Picture 9**. Flatness and Symmetry for 18 MV


 * Picture 10**. Flatness and Symmetry 6 MeV


 * Picture 11**. Flateness and Symmetry 12 MeV

**Procedure:** Radiation Isocenter Collimator

 * With the gantry vertical, we placed a ready pack film flat on the taletop at the SAD. We opened the upper jaws of the collimator wide and close the lower jaws to obtain a narrow slit of minimum possible width. By rotating the collimator through a number of different angles, the film was exposed to obtain a star pattern. The processed film shows star patterns, with a dark central region.

**Tolerance:**

 * For an acceptable result, all the lines should intersect or pass within a 2mm-diameter circle.


 * Picture 12**. Radiation Isocenter Collimator

**Procedure:** Radiation Isocenter Gantry

 * A ready pack film, sandwiched between two plastic sheets was placed on the table so that the plane of the film was perpendicular to the plane of couch tip and contained the beam central axis for all gantry angles. We created a slit of beam parallel to the gantry axis of rotation and exposed the film at every 40 degrees.

**Tolerance:**

 * The gantry star pattern should show the lines intersecting or passing within a 2-mm diameter circle centered around the presumed radiation isocenter.


 * Picture 13.** Radiation Isocenter Gantry

**Procedure:**

 * Safety interlocks and emergency off switches were checked.

**Tolerance:**

 * All interlocks and emergency off switches have to be functional



**Procedure**:

 * ===**Quantitative Dynamic MLC Performance (DynaLog analysis)**===

A sweeping gap dynamic MLC plan moving at aprox 2cm/s,is evaluated at 4 angles. Resulting dynalog files are evaluated. Test evaluates MLC performance over time, errors in leaf position accuracy and impact of gravity. || **Procedure:**
 * **MLC Performance results:** || Specification: |||| Max position error RMS of any leaf = .35cm95% of error counts < .35cm || **Comments:**
 * Angle |||||| Max RMS || % < .35 ||^  ||
 * 360 ° ||||||   ||   ||^   ||
 * 270 ° ||||||   ||   ||^   ||
 * 180 ° ||||||   ||   ||^   ||
 * 90 ° ||||||   ||   ||^   ||
 * 90 ° ||||||   ||   ||^   ||
 * **MLC Performance (Picket Fence) during ARC Rotation**

Picket fence is recorded using Portal Imager. Analysis of MLC Picket fence provides information leaf and carriage positon accuracy, carriage sku, and corruption of MLC calibration files. Test is performed at a single gantry angle ||
 * **MLC Performance results:** |||| Specification: || Observation consistent with description || **Comments:**
 * Observation |||| Description ||^  ||
 * Leaf and Carriage Position |||| Looking horizontally, all MLC leaf ends should join at each gap, if a leaf is lagging the gap will appear thicker or offset from the others. ||^  ||
 * MLC Alignment |||| Compare the horizontal gap lines with the cross hair projection. Lines should be parallel within .5mm across MLC image. Gap lines that are wider on one side then the other are indicative of carriage sku. ||^  ||
 * Light field correction |||| The intensity of each horizontal line should be similar. Deviation in line intensity is indicative of an error in rounded leaf end correction contained in the MLCTable.txt calibration file. ||^  ||
 * Light field correction |||| The intensity of each horizontal line should be similar. Deviation in line intensity is indicative of an error in rounded leaf end correction contained in the MLCTable.txt calibration file. ||^  ||

**Procedure:**

 * ===MLC Speed versus ARC Speed Rotation and Dose Rate Test===

Accurate control of Dose Rate and Gantry Speed during RapidArc delivery This test uses 4 combinations of dose-rate, gantry range and gantry speed to give equal dose to 4 1.8 cm strips in a RapidArc field If field appears inconsistent collect an open field image and compare the non-flatness corrected image. Data in each segment should be within 2% of mean. ||
 * **Rapid Arc, Dose rate test mlc speed** **results:** || Specification: || Consistent with baseline profile of PV image || ** Comments: **
 * ^  || Results: || Consistent with baseline profile of PV image ||^   ||



References:
Monthly QA. Minneapolis VA, Minneapolis, MN. October 2012. Monthly QA. Joe McMahon. Delnor Hospital, Geneva IL. Interview on Oct 18, 2012 Monthly QA. Glenn Collins.MSDABR., Maine General Medical Center, Augusta ME. interview Oct. 10, 2012 Monthly QA. Maine General Medical Center, Augusta ME. Oct. 2012

**Procedures:**
Once technological equipment is hooked up, three relative readings are taken at a set energy, field size and MU setting. This is in order to establish a background reference reading. The physicist records field, MU and electrometer charge reading with a tolerance of +/-3%. Dose maps for all treatment beams are compiled. The diodes and ion chamber give the dose map. Our facility uses the Arc Check phantom, which is not a flat surface, so our software corrects for this geometry difference.
 * Treatment room and QA devices are setup for QA completion.
 * Sun Nuclear Arc Check phantom with insert is aligned via treatment room lasers. This phantom has small diodes around its exterior.
 * An ion chamber is inserted into the phantom which is used to measure a point dose.

The actual readings are compared with the planned readings. Machine calibration effect is taken out, so this is a test of just the comparison based on the ion chamber readings
 * Analyzed with gamma analysis compiled of two parameters
 * % difference (in measured and calculated dose) +/-3%
 * Distance to agreement (good for on gradients) +/-3%
 * <95%=red on measurement device, and steps would be taken to either get the readings into the green, or evaluate why the readings are not within range
 * 95-97%=yellow. Acceptable
 * >97%=green. Good to go.
 * Computer analyzes and tells which values fail and which pass.
 * Calculate dose for ion chamber
 * Build spreadsheet
 * Put in original “background” readings
 * Enter actual readings
 * % difference should be within +/-3%

**Types of equipment** (provide links to websites if desired):

 * Sun Nuclear Arc Check
 * []
 * Precision electrometer and densitometer

**Tolerances** (expected):

 * Dose output for IMRT plans need to +/-3 % inorder to pass.

**Images:**
**Picture 1:** Sun Nuclear Arc Check phantom with insert

<span style="background-color: #ffffff; font-family: Arial,sans-serif;">**Picture 2**: Precision electrometer and Dosimeter model 525


 * References:**
 * 1) Conversation with Dave Ellerbusch Phd. Physicist at the Minneapolis VA on October 4, 2012.
 * 2) Low DA, Moran JM, Dempsewy JF, Dong L, Oldham M. Dosimetry tools and techniques for IMRT [The American association of physicists in medicine]. 2011. Available at: [].

**Procedures:**

 * Process may include completing TPS QA monthly or quarterly according the NHPP.[1] However, some clinics also preform annual TPS QA.[6] Historically it was common to complete testing only upon upgrading to a new model. TPS QA can be completed by Medical Dosimetrists or Physicists.
 * The goal of this testing is to ensure that the output data dose not and has not changed from initial calculations and checks made.[1] Each modality utilized at this facility is checked in plans often including: photons, electrons, off cord/blocking, off axis points, and IMRT.
 * A phantom is scanned (head and neck, lung, pelvis, and IMRT pelvis) and planned for any/all machines. Testing is completed to confirm that that calculation models calculate the same values as the previous quarter. The monitor units are what are evaluated upon calculation.
 * This data is then sent to second check software such as MuCheck or Radcalc, and verified through that system. Not only should these values be within tolerances +/-3%), but they should also match previous calculations produced in previous quarters through the second check software.
 * TPS QA is an evolving QA measure, and should be adapted to changes and measures fitting to a facility.[2]

Annual QA for TPS requires several steps and is more of a consistency checks. There are 11 different types that are done annually or even can be done Monthly or when a clinic or institution conducts it:


 * 1) Create a plan to deliver 100 MU for various field sizes and depths in the phantom. Compare dose values obtained from with those previously calculated using the calculation check software.[6]
 * 2) Deliver 100 MU to a depth of 10 cm in plastic water for a 10x10 cm field for all wedges, and convert to dose in water. Compare dose values obtained from measurement with those calculated by TPS. The acceptance criterion is +/- 2 %.[6]
 * 3) Deliver 100 MU to a depth of 5 cm solid water buildup on top of the Profiler. Four Enhanced Dynamic Wedge fields were selected which covered different wedge angles, wedge directions, field sizes and energies. Both the dose output at the central axis point and the profile along wedge direction were compared to those calculated from TPS. The acceptability criteria are +/- 2% for all settings.[6]
 * 4) Standard Cases. Project beams with dimensions of 6x6, 10x10 and 30x30 cm on to the surface of a phantom (Phantom Pelvis;100 cm SSD). Compare depth dose curves with those from commissioning. Doses at depths in the buildup should agree to within +/-10%, while all other doses should agree, on average, +/-2%.[6]
 * 5) Standard Cases. Project a 10x10 cm beam onto the flat surface of a phantom at a setup of 100 cm SSD for all electron energies. Compare depth dose curves with those from commissioning measurements. Depths of various dosimetric parameters should agree to within +/-0.1 cm.[6]
 * 6) Standard Cases. Project a 25x25 cm beam onto the flat surface of a phantom at a setup of 100 cm SSD for all electron energies. Compare depth dose curves with those from commissioning measurements. Depths of various dosimetric parameters should agree to within +/-0.1 cm.[6]
 * 7) Create 2 separate volumes (same structure) in the solid water phantom each and separated laterally by about 10 cm. Design two treatment plans: a) Deliver 100 cGy to isocenter for one of the structures with 6x6 cm field; b) Deliver 100 cGy to isocenter between both structures. Set field size to 20x20cm to encompass both structures. Compare DVHs with idealized DVH. Compare total volume with actual volume. (Ideal DVH images are shown below)[6]
 * 8)Scan in a particular phantom that had four different densities into TPS. Measure the dimensions of the phantom and the diameters of the 4 circular plugs(the for plugs all have different densities). Evaluate the electron density of the plugs and compare with nominal values. Contour the plugs (there are four different densities), as well as the external surface of the phantom. Compare the volumes from TPS with actual volumes.[6]
 * 9)Using a specific phantom, position a beam at the surface (100 cm SSD) on the center of the crosshair. Set the beam dimensions to 10x10 cm, and verify that the beam edges are aligned with the markers on the phantom surface. The image below shows that the beam edges correspond to the marks etched on the surface of the phantom.[6]
 * 10)Using the solid water phantom, position a beam at the surface (100 cm SSD) on the surface. Set the beam dimensions to 10x10 cm, and display the 100%, 80%, 70%, 60%, 40% and 20% isodose curves. Place a dose point along each isodose curve and verify that the dose point displays the correct isodose value.[6]
 * 11) End-to-End Test. Scan the solid water phantom with the ion chamber insert located at a depth of 10 cm from the anterior and 15 cm from the posterior surface. With the isocenter at the center of the chamber, the following plans were created tthen going back to deliver the plan and verify the dose and dose output.[6]

Periodic QA2 • Hardcopy output • Computer files • Review clinical treatment planning || • Problem review • Review hardware, software and data files || • Review digitizer, CT/MRI input, printers, etc. • Review BEV/DRR accuracy, CT geometry, density conversions, DVH calculations, data files and other critical data || software upgrade ||
 * Frequency || Item ||
 * •Daily || • Hardware/software change logs • Error logs ||
 * • Weekly || • Digitizer
 * • Monthly || • CT data input
 * • Annual || • Dose Calculations
 * • Variable || • Recommissioning due to machine changes or

**Types of equipment**:

 * Radcalc []


 * MuCheck []

[] []
 * Rando Phantoms []


 * Pinnacle3 TPS []


 * Eclipse TPS []

Or any other Treatment Planning system that are being used for patients.

**Tolerances** (expected):

 * No set tolerances, just checking that Monitor Units from previous quarters match current readings.
 * Site specific.[1]

**Images:**





 * Radcalc


 * MuCheck




 * Rando Phantoms


 * References:**
 * 1) Conversation with James Schmitz, CMD. Medical Dosimetrist at Minneapolis VA on 10-8-11.
 * 2) Merrill R, Miller M. Treatment planning system quality assurance. Presented at American Association of Medical Dosimetrists Meeting; June 10, 2012; Herndon, VA. Available at: [].
 * 3) American Association of physicist in Medicine Radiation Therapy Committee Task Group 53, Quality assurance for clinical radiotherapy treatment planning, Med. Phys. 25 (1988) 1773‐1829.
 * 4) International Atomic Energy Agency, Commissioning and Quality Assurance of Computerized Planning Systems for Radiation Treatment of cancer Technical Report Series Number 430, IAEA, Vienna 2004.
 * 5) Boyer, A.L., etc. al, Quality Assurance for Treatment Planning Dose Delivery by 3DRTP and IMRT, American Association of Physicist in Medicine, Medical Physics Monograph Number 26 (2000).
 * 6) Roeske, John C. Annual Treatment Planning QA for XiO. Loyola University Medical Center. March 22, 2012.

**Procedures:** P**ositional accuracy**

 * Checked by extending the kV source arm and detector arm and measuring the distances from the isocenter to the surface of each. Movement and present positioning accuracy is also checked by moving the detector arm to a predetermined position, measuring the distance from the isocenter and verifying the change in distance with a ruler.[1]

**Types of equipment:**

 * Meter stick ruler

**Tolerances (expected):**

 * kV source to isocenter distance: 85.1cm +/- 2mm
 * kV detector to isocenter distance: 45.1cm +/-2mm
 * kV detector (position 2) to isocenter distance: 25.1cm +/-2mm

**Images:**

 * Picture 1:** Measurement of distance from kV source to isocenter.


 * Picture 2:** Measurement of distance from kV detector to isocenter.

**Procedure:** **CBCT Image Quality**

 * checked by taking a CT scan of the Catphan phantom with predetermined CBCT settings, such as slice thickness = 2.5 mm, resolution 384x384 and scan diameter 24 cm. The CT image is acquired. Prior to image registration with the "Planning CT phantom CT image", spatial linearity is measured in the x and y axis and spatial resolution is measured and recorded. To measure spatial linearity, two points in the phantom that are a known distance apart are measured. To measure the spatial resolution, a slice on the phantom with spaced high density material is located and the visibility of spaces is checked. Image registration is then done, shifts are acquired and completed. The room lasers are then checked to ensure that they are aligned with a bb on the surface of the phantom. This verifies that the shifts generated during the image registration are being sent to the table console correctly.[1]

**Types of equipment**:

 * Catphan phantom: http://www.phantomlab.com/library/pdf/catphan504manual.pdf
 * Bubble level to ensure phantom is level prior to imaging

**Tolerances (expected):**

 * Lasers within 2mm of bb on phantom
 * Spatial linearity within 1%

**Images:**
Catphan Phantom:

Spatial Linearity:

Spatial Resolution:

**Procedure:** **kV image quality**

 * checked through imaging of multiple phantoms. The Leeds phantom is imaged with fluoroscopy techniques to determine spatial resolution and low contrast sensitivity. Images are taken with and without a copper filter. Using the filter removes the low energy photons from the beam. The step phantom is imaged to determine the gray scale linearity.[1]

**Types of equipment**:

 * Leeds Phantom
 * Copper filter
 * Step Phantom

**Tolerances (expected):**
Tolerances for the image quality are difficult to define. The purpose of taking these images monthly is to ensure that image quality is not degrading over time. By comparing images taken previously, image quality should be documented as equal to or improved from the previous images. If image degradation is observed, the equipment vendor should be contacted.[1]

**Images:**

 * Picture 1:** Leeds phantom with copper filter


 * Picture 2:** kV image of Leeds phantom


 * Picture 3:** Step phantom.


 * Picture 4:** Step phantom set on kV detector for imaging.

**References:**
1. Conversation with Dr. Frank Goodin, Lead Medical Physicist at Turville Bay Radiation Oncology. October 15, 2012.

**Procedures:** P**ositional accuracy**

 * Daily, along with morning QA an isocenter verification is completed by placing the verification phantom on the table in a location other than the isocenter (with no rotational deviation). The couch is then enabled to reposition the phantom to the treatment isocenter, a visual laser check is performed comparing the location to marks on the phantom. Images are then acquired and shifts are made to the images to show deviation from the isocenter acquired in the Exac-trac software. Any deviation of more than 1mm is reported.
 * Weekly a Calibration is completed, this process sets the isocenter in the Exac-Trac software in order to verify that it is relative to the room isocenter. This is done with the Exac-Trac calibration phantom which is also placed on the table and automatically moved to isocenter. This phantom consists of many external as well as internal markers that are aligned with the Exac-Trac software

**Types of equipment:**

 * Multiple Isocenter phantoms provided by the manufacture (Brainlab)

**Tolerances (expected):**

 * Any visual deviation of laser location when compared to phantom marks of greater than 2mm is reported
 * All other tolerances are programed into the Exac-trac software and calibration/verification will be unsuccessful in the system and will not allow you to proceed until the problem is corrected

**Images:**

 * Exac-Trac Isocenter verification phantom**


 * Exac-Trac isocenter calibration phantom**


 * Image from the Exac-Trac software showing the alialignment of the internal markers of the calibration phantom**