Setting up the PTS Communication
For the IBA PT users with Proton Therapy System (PTS) version R11, myQA Machines PT provides an automation of measurement and analysis. To be able to use this function, the communication between myQA Machines PT and the PTS must be established by doing the following:
- Open the file, IBADos.CSP.Run.Shell.exe.config, in C:\Program Files (x86)\IBA Dosimetry\myQA with a text editor, e.g., Notepad, and move down to the line, “<add key="MOA_DOPA_HOSTNAME” value="" />"
- Insert the IP address and the port of the room in which the DOPA server is running, e.g., “10.192.254.8:8081” or “tcrw1.ptcg.org:8081”. See an example below:
In this example, the IP addresses of two PTS server in two treatment rooms are inserted. If there is more than one IP address, they will appear in the dropdown list of the Auto button in the Test Run workspace. The user should select the room for performing QA.
- Click File > Save
Creating PBS Layer Definition Files
In a myQA Machines PT protocol, the PBS Layer Definition (PLD) file which defines the daily QA irradiation pattern is used for defining the test. A PLD file can be created by simply saving a plain text file with file extension “.pld”. In the PLD file, energies are defined by layers, starting from the distal energy to the proximal energy. Each layer represents an energy. In a layer, spots are defined by a position [X, Y] and dose (MU).
See an example of IBA PLD file for the Lynx PT with Sphinx phantom
The structure of a PLD file can be summarized as:
1st line - PLD Header: A summary of information for the PBS field, defining total dose, dose per meterset weight, and number of layers.
2nd line - Layer Header: Defines the energy of the Layer and the sum of meterset weight.
3rd line - Spot Data: Each spot is defined by a position and a dose.
When a PLD file is uploaded into myQA Machines PT, the only information captured by the software are the layer’s energy and spot coordinates.
The PLD image shows that a certain pattern is used for a specific test. When defining a test that requires defining an area for analysis (the object of interest, OOI), the OOI should cover the pattern that is designated for the test.
PLD for Lynx PT with Sphinx Phantom
An example of a PLD image for the Lynx PT with Sphinx phantom for daily QA check in proton beams. All layers are selected to display. The patterns with the same color highlight boxes have the same energy, which is indicated in the energy layer button with the same color box.
1: Click All or an energy button to display all energy layers or the selected layer
2: Homogeneity analysis
3: Coincidence X-ray isocenter versus particle beam
4: Energy analysis
5: Single spot analysis
6: Output (PPC05)
Coordinates and irradiation dose of the test patterns
Rectangle areas (2, 4, and 6):
- Irradiated areas (2, 4, and 6): Spacing 3 mm, 0.99 MU / spot (≈ 100 × lowest spot MU that can be delivered by the particle treatment system)
- The coordinates of the 4 corners are listed in the table below. The corners are labelled with a, b, c, and d clockwise and starting with the upper-left corner as “a”
Table 3.1. Coordinates of the rectangle areas for different analyses
| Corner | (a) x, y/mm | (b) x, y/mm | (c) x, y/mm | (d) x, y/mm |
| Area 2 (Homogeneity) | -78, 144 | 78, 144 | 78, 126 | -78, 126 |
| Area 4i (Energy, 106 MeV) | -75, -6 | -60, -6 | -60, -102 | -75, -102 |
| Area 4ii (Energy, 145 MeV) | -75, 105 | -60, 105 | -60, 9 | -75, 9 |
| Corner | (a) x, y/mm | (b) x, y/mm | (c) x, y/mm | (d) x, y/mm |
| Area 4iii (Energy, 172 MeV) | 57, 6 | 72, 6 | 72, -102 | 57, -102 |
| Area 4v (Energy, 221 MeV) | 57, 105 | 72, 105 | 72, 9 | 57, 9 |
| Area 6 (Output (PPC05)) | -27, -83 | 27, -83 | 27, -137 | -27, -137 |
Spots (5) for spot analysis:
- The coordinates of the spots (5) on the left are labelled with l1 to l8 from top to bottom, on the right are labelled r1 to r8 from top to bottom.
| Left | Right | ||||
| No. (energy/MeV) | x, y / mm | MU | No. (energy/MeV) | x, y / mm | MU |
| 5l1 (221) | -123, 123 | 20 | 5r1 (221) | 123, 123 | 20 |
| 5l2(172) | -123, 77 | 20 | 5r2 (221) | 123, 83 | 8 |
| 5l3 145) | -123, 47 | 20 | 5r3 (221) | 123, 53 | 10 |
| 5l4 (106) | -123, 17 | 20 | 5r4 (221) | 123, 23 | 12 |
| 5l5 (221) | -123, -13 | 2 | 5r5 (221) | 123, -13 | 14 |
| 5l6 (221) | -123, -43 | 4 | 5r6 (221) | 123, -43 | 16 |
| 5l7 (221) | -123, -73 | 6 | 5r7 (221) | 123, -73 | 18 |
| 5l8 (221) | -123, 103 | 20 | 5r8 (221) | 123, 103 | 20 |
Spot (3) for Coincidence X-ray imaging isocenter versus particle beam analysis: (0, 0), 106 MeV, 20 MU
PLD for Sphinx Compact
An example of a PLD image for Sphinx Compact system. All layers are selected to display. The patterns with the same color highlight boxes have the same energy, which is indicated in the energy layer button with the same color box.
1: Click All or an energy button to display all energy layers or the selected layer
2: Homogeneity analysis
3: Coincidence X-ray isocenter versus particle beam
4: Energy analysis
5: Single spot analysis
6: Output (PPC05)
In this example, the PLD has been created for using the Sphinx Compact with the gantry at 90°. Beam
energies indicated in the figure are those to be used in protons beams. They correspond to a range in water of about 7.7 mm, 15.8 mm, and 26 mm for the 100 MeV, 150 MeV and 200 MeV, respectively. If the Sphinx Compact device is used in carbon ion beams, the 3 energies that can be used to obtain the same water ranges are about 200, 300, and 402.8 MeV/n.
Coordinates and irradiation dose of the test patterns
Rectangle areas (2, 4, and 6):
- Irradiated areas (2, 4, and 6): Spacing 3 mm
- The coordinates of the 4 corners are listed in the table below. The corners are labelled with a, b, c, and d clockwise and starting with the upper-left corner as “a”.
Table 3.3. Coordinates and irradiation dose of the rectangle areas for different analyses
| Corner | (a) x, y/mm | (b) x, y/mm | (c) x, y/mm | (d) x, y/mm | MU/spot |
| Area 2 (Homogeneity) | -30, 88 | 90, 88 | -30, 70 | 90, 70 | 0.5 |
| Area 4i (Energy, 200 MeV) | -62, -17 | -50, -17 | -50, -95 | -62, -95 | 0.2 |
| Area 4ii (Energy, 150 MeV) | 50, -17 | 62, -17 | 62, -95 | 50, -95 | 0.2 |
| Area 4iii (Energy, 100 MeV) | 78, -17 | 90, -17 | 90, -95 | 78, -95 | 0.2 |
| Area 6 (Output (PPC05), 120MeV) | -30, -25 | 30, -25 | 30, -85 | -30, -85 | 1.0 |
Spots (5) for spot analysis:
- The coordinates of the spots (5) on the left are labelled with h1 to h6 from left to right for the horizontal spots and v1 to v7 from top to bottom for the vertical spots.
| Horizontal | Vertical | ||||
| No. (energy/MeV) | x, y / mm | MU | No. (energy/MeV) | x, y / mm | MU |
| 5h1 (200) | -45, 40 | 1 | 5v1 (200) | -84, 75 | 7.5 |
| 5h2 (175) | -20, 40 | 1 | 5v2 (200) | -84, 50 | 6 |
| 5h3 (150) | -5, 40 | 1 | 5v3 (200) | -84, 25 | 4.5 |
| 5h4 (125) | 30, 40 | 1.5 | 5v4 (200) | -84, 0 | 3 |
| 5h5 (100) | 55, 40 | 2 | 5v5 (200) | -84, -25 | 2 |
| 5h6 (70) | 80, 40 | 3 | 5v6 (200) | -84, -50 | 1 |
| 5v7 (200) | -84, -75 | 0.5 | |||
Spot (3) for Coincidence X-ray imaging isocenter versus particle beam analysis: (0, 0), 100 MeV, 7 MU
Please note that, the coordinates above might have to be adapted to the beam coordinate system of the user’s particle treatment system to deliver the described test patterns.
An example of a PLD defined using proton beams (Sphinx Plugin-PLD Template.pld) shown in the figure above can be found in C:\ProgramData\IBA Dosimetry\MachineQA\SphinxSamples
About Baseline Measurements
Initial measurements should be performed to generate baseline and tolerance values. These values are
then entered into a myQA Machines PT protocol. They will be used as references for comparison. Therefore,
the baseline should be taken with the same measurement setup as for subsequent daily QA checks.
The baseline includes an X-ray image, a DICOM CT image of the Sphinx phantom, output measurement (e.g., with DOSE 1 and PPC05 chamber), and a complete beam image. For Output and Couch Translation tests, the baselines are measured outside the myQA Machines PT. For Energy, Homogeneity, Spot, and Coincidence tests, the baselines can be measured in the myQA Machines PT when creating the machine protocol.