Setting up Devices in a Proton Treatment Unit
Lynx PT with Sphinx Phantom
Installing the Lynx driver
The Lynx driver must be installed manually. In the location, C:\ProgramData\IBA Dosimetry\LynxDriver\, double-click the file, manual_install_fc2_w10_x64.bat, and then follow the installation instructions.
Measurement setup
Normally, the Sphinx phantom, which is attached to the Lynx PT, is always oriented on the patient couch as shown in the photo below. However, the Lynx PT can be oriented in 4 positions. The Sphinx phantom is aligned through the X-ray imaging system, the in-room lasers can be checked on the markers engraved on the phantom frame. See Section 2.2 for the detail procedure for setting up the Lynx PT and Sphinx phantom.
Orientation of the Lynx PT device
Example: The orientation of the Lynx PT with Sphinx phantom at gantry angle 0˚
The orientation of the Lynx PT needs to be entered into the software for the test (see Section 2.2.5, myQA
Machines PT Reference Guide). The illustration below shows different orientations of the Lynx PT detector.
Illustration of the Lynx PT orientations. In Beam’s Eye View, the Lynx rotated counterclockwise 90˚ is +90˚
Sphinx Compact
The phantom is aligned with the in-room lasers to central fiducial and the markers engraved on the
phantom frame. The photo below shows a setup where the Sphinx Compact is orientated for the gantry angle at 90°. The PLD and template included in myQA are made for the gantry at 90°.
Example: the orientation of the Sphinx Compact with gantry angle at 90˚
IMPORTANT NOTICE: INTERRUPTION OF DATA TRANSMISSION (SPHINX COMPACT ONLY)
At the low AC input, if the input voltage has voltage dips or short voltage interruptions, the Ethernet data transmission may be interrupted. In this case, an error message will appear. This is a safety measure to prevent using the erroneous data.
Please see Sphinx Compact User’s Guide for the detail procedure for setting up the Sphinx Compact system.
Orientation of the Sphinx Compact devive
The Sphinx Compact can be used with Gantry at 0°, 90° and 270° (see an illustration below). The orientation of the Sphinx Compact needs to be entered into the software for the test (see see Section 2.2.5, myQA Machines PT Reference Guide).
Illustration of the Sphinx Compact orientation at gantry angles of 90°, 0°, and 270°
Setting up Lynx PT with Sphinx Phantom
To perform output consistency verification, the PPC05 chamber is inserted into the phantom and is connected to an electrometer compliant with IEC60731 and located in the control room.
Lynx PT detector - Sphinx phantom system (the electrometer is not shown)
Note: The Lynx PT detector is intended to be used with the PBS delivery mode only. The use of the Lynx PT with other modalities such as Double Scattering or Uniform Scanning may cause damages to the camera due to the production of neutrons generated in the vicinity of the snout apertures commonly used with Scattering and Uniform Scanning beam delivery modes.
Note: When the PT treatment system has a medPhoton ring, a slightly modified phantom, Sphinx SF phantom, can be used. Compared with Sphinx phantom, Sphinx SF phantom has a smaller frame so that it fits into a smaller space. Since this modification does not affect the device setup process, only Sphinx Phantom is used for demonstrating the setup process in the next section.
Device Locations and Connections
Location and connection of the Daily QA PBS measurement devices
The Sphinx phantom incorporates four wedges with various thicknesses for verifying the constancy of several beam energies. There are different ways to combine the blocks for more variations. A dedicated block can contain a PPC05 chamber for dose output constancy check. The phantom allows the in-air measurement of spots at the level of the Lynx. The Lynx is connected to a PC in the control room. The
PPC05 chamber is connected to an electrometer (e.g., DOSE 1) that is also placed in the control room.
Connection between the Lynx PT and PC
The Lynx is connected to a PC through the provided Ethernet PoE Injector/firewire:
- Plug the connector with a round metal cover of the 30 m network cable to the Lynx and the other end of the cable to the Data Out port of the Injector.
- Plug one end of the 3 m network cable to the Data In port of the injector and the other end to the PC
- Connect the injector to a power supply with the provided power cord.
The green LED of the injector should turn on. If not, check the connections.
Setting up Sphinx Phantom
Mount the Positioning Bar
Before using the phantom, the positioning bar should be mounted on the phantom bottom. There are five possible positions. The distance between the adjacent positions is 20 mm.
Bottom side of the phantom. 1: 5 mounting positions, 2: Positioning bar & mounting screws
Combine Different Build-up Inserts for Different Build-up Thickness
Fixed block
The fixed RW3 block in the Sphinx phantom has five dovetail slots. There are six insert blocks with a dovetail. By plugging a dovetail into a dovetail slot, the fixed block can be combined with the insert blocks to create different build-up thickness or install a PPC05 chamber using the dedicated chamber block.
Sphinx phantom with basic blocks, left: top view, right: fixed blocks which the dovetail slots are numbered, rear view
PPC05 insert block, build-up inserts central fiducial
a: PPC05 block for holding the PPC05 chamber. Its dovetail is inserted into slot 5.
b: PPC05 insert to be inserted in slot 7 to provide 3 cm build-up for the PPC05 chamber.
c, d, and e: RW3 Insert 250, 200, and 100. They can be inserted into slot 3 or 4 to add thickness of 250, 200, and 100 cm as desired.
1, 2, 5, and 6: these slots are for the central fiducial insert:
Fiducial insert
Loose the screw of the fiducial insert to change the length of the pin. The tip of the pin is normally placed at isocenter.
Slot fillers
If a slot in the fixed block is not used by an insert, fill it with a slot filler of correct length.
Slot fillers, 3 cm and 3.5 cm length
Installing the PPC05 Chamber
- Press the PPC05 chamber to the chamber slot (1) until the surface of the chamber is flat to the surface of the block.
PPC05 block
Note: With the O-ring on the PPC05, the chamber sits very tight inside the slot. If planning to remove the chamber later, it is recommended to remove the O-ring before putting it in the slot. - Cover the PPC05 with the 3 cm thickness block (2) so the chamber has 3 cm build-up.
Install Films
Films can be easily mounted on the Sphinx with the film mounting set:
1: Long clip, 2: Short clip, 3: Spacers, 1 cm, 2 cm, 5 cm, 4: Magnet
With long arms, several films can be mounted parallel to each other. Spacers with three different lengths can be used to arrange the distances among the films. See an example below:
1: The film is held by a clip and a magnet, 2, 3, 4: Spacer 2 cm, 5 cm, 1 cm
With two short arms, a film can be mount parallel to the mounting side of the phantom:
Setting up Lynx PT with Sphinx Phantom on a PT Treatment Couch
- Prepare the Sphinx phantom (see the previous section):
- Mount the positioning bar at one of the five mounting positions on the bottom side.
- Install the PPC05 chamber if needed.
- Insert the central fiducial insert.
- Insert the desired inserts. Insert the slot fillers to the unused slots.
- Place the index bar (1, belonging to the treatment system) of the patient coach to a pair of index notches (2) at the desired position.
- Place the Sphinx next to the index bar.
- Attach the Lynx to the Sphinx.
Sphinx - Lynx PT mounting side, 1: Holes for mounting the Lynx PT
1: Positioning bar (Index bar was removed)
- Connect the PPC05 to the electrometer.
- Connect the Lynx PT to the PC via an Ethernet cable. For establishing the network connection between the Lynx and PC, see Section 2.2.5.
- Inside the blocks, there are four fiducials. Take an X-ray image and save the reference image. In the
following days’ setup, compare the positions of the four fiducials with those in the reference image. If there is difference, move the PPS so that the position of the phantom is the same every day. - Verify the laser matches the markers of the phantom and scintillator.
Lynx PT detector - Sphinx phantom system on the PPS, the orientation of the Lynx PT is at 0˚. 1: Phantom, 2: Sphinx: Scintillator, 3: Markers
Using Sphinx Clips
A pair of clips are provided for improving the coupling between the Sphinx phantom and Lynx PT.
- At a location shown below, place a clip across the contacting frame edges of the Sphinx phantom and Lynx PT. If necessary, turn the knob so that the clips holds on position.
- Repeat the about step to install the second clip.
- Secure both clips by tightening the knobs.
Network Connection between Lynx PT and PC
The Lynx PT can be connected to the computer directly through a small local network between the computer and the device. Aftering installing the myQA SW, a tool, NetConfigLynx2D.exe, is available for setting up the IP address in the computer to form a a small local network with the Lynx PT device.
Prerequisites: The Lynx PT and computer is connected through an Ethernet cable, and both devices are powered on.
- Open Control Panel of Windows. Click Network and internet, Network and sharing center, and then View your network status and tasks.
- Click Ethernet under Access type: No network access.
- Click Properties in Ethernet Status (see the screenshot below, left).
- In Ethernet Properties, deactivate Internet Protocol Version 6 (TCP/IPv6); click to highlight Internet Protocol Version 4 (TCP/IPv4); click Properties, and then OK (see the screenshot left). The Internet Protocol (TCP/IP) Properties dialog opens (see the screenshot right).
- Select the round-button Obtain an IP address automatically.
- Click Close to close the Ethernet Properties window.
- Click Close to close the Ethernet Status window.
- Double click NetConfigLynx2D.exe in C:\ProgramData\IBA Dosimetry\LynxDriver. Once the tool stop
running, the setup is finished.