myQA SRS Phantom
The myQA SRS Phantom is an accessory which is intended for the placement of the myQA SRS device or other measurement devices such as ionization chambers and films in the course of the Patient QA workflow including, but not limited to CT, 2D-MV, 2D-kV, MV CBCT, and kV CBCT imaging, treatment setup and irradiation on radiotherapy treatment devices.
Furthermore, purely passive inserts can be used, such as (but not limited to) an insert bearing a sphere for providing a Winston-Lutz test, or to provide reference volumes and materials to be able to carry out end-to-end tests. See Section 3.2.3 for more information of available chambers and inserts.
Phantom Versions
- myQA SRS Phantom^2: the latest version of the conventional phantom. See Section 3.2.2.1 below for more information.
- myQA SRS Cyberknife Phantom: a version specifically designed for compatibility with Cyberknife LINACs and the myQA SRS Cyberknife detector. See Section 3.2.2.2
Rotation
The myQA SRS Phantom, thus myQA SRS, can be rotated.
A scale from 0° to 360° with markers at every 1° is printed on the ring of the phantom.
Different size markers for 1°, 5°, and 10° increments ensure accurate positioning for measurements.
Use the fixation screw (1) to lock the phantom cylinder at a specific orientation.
The rotation scale direction of myQA SRS is the same as the gantry:
Gantry and myQA SRS phantom at 0° (viewed towards the gantry)
myQA SRS Phantom2
The myQA SRS Phantom2 is MR safe (see Safety Labels) and features the following updated functionalities:
- Smaller cylinder cap and reduced radius (1)
- Dashed lines for 1-cm offset alignment in the three directions (2)
- Combined-field dashed-line at 6-cm axial offset (3) (see Section 4.1 myQA Patients Instructions for Use for Combine Fields measurement procedure)
- A larger base plate (4)
- Four leveling pins (5)
- Additional handles for improved lifting and carrying (6)
Please see Section 7.2 for technical specifications.
Phantom Inserts
Various inserts are available for the different myQA SRS Phantoms. The inserts are designed so that the reference point of the chamber / detector and film layer position coincides with the intersection of the isocentric planes as indicated by the alignment markings on the myQA SRS detector. For material and mass density information see Section 7.2.
Available IBA Phantom Inserts
- Uniform Chamber Insert See Section 3.2.3.1 for list of available chamber / detector adapters
- Film Insert
- Winston-Lutz Insert
- Imaging and Planning Insert
Examples of inserts; 1: Film insert; 2: Uniform Chamber insert; 3: chamber adapters
Uniform Chamber Insert
The Uniform Chamber insert has adapters to support the use of different chambers / detectors in the phantom. The inserts are designed so that the geometric center of the chamber /detector sensitive volume coincide with the sensor layer of the myQA SRS.
Available adapters for the Uniform Chamber insert
| Adapter Label | Supported Chamber / Detector | Vendor |
| FC65 | FC65-G / FC65-P Farmer Type Chambers | IBA Dosimetry |
| CC04 | CC04 Compact Ionization Chamber | |
| RAZOR CHAMBER | RAZOR / CC01 Compact Ionization Chamber | |
| RAZOR NANO | RAZOR Nano Compact Ionization Chamber | |
| MicroD | microDiamond Synthetic Diamond Detector (60019) | PTW |
| PP3D | PinPoint 3D Ion Chamber (31022) | |
| 30010 / 30012 | PTW Farmer® Ionization Chamber | |
| SF 31010 | Semiflex Ionization Chamber 31010 | |
| SF 31013 | Semiflex Ionization Chamber 31013 | |
| A1SL | A1SL Exradin® Ion Chamber, Slim Line Miniature Shonka, 0.053cc | Standard Imaging |
| A12 | A12 Exradin® Ion Chamber, Waterproof Farmer Type, 0.64cc | |
| A16 | A16 Exradin® Ion Chamber, MicroPoint, 0.007cc | |
| A19 | A19 Exradin® Ion Chamber, Waterproof Classic Farmer, 0.62cc | |
| A26 | A16 Exradin® Ion Chamber, MicroPoint, 0.015cc | |
| W1-1×3 | Exradin® W1 Scintillator 1×3 | |
| W2-1×1 | Exradin® W2 Scintillator 1×1 | |
| W2-1×3 | Exradin® W2 Scintillator 1×3 |
Film Insert
CAUTION ENSURE PROPER POSITIONING OF FILM INSERT IN THE PHANTOM
Always pay particular attention to the proper positioning of the film insert in the phantom.
Make sure that the insert is not flipped, and that the film is not flipped in the insert.
End-to-End Test Inserts
To support clinical End-to-End tests, two inserts are available as accessories for the myQA SRS system and compatible with the myQA SRS Phantom.
Winston-Lutz Insert
The Winston-Lutz insert is designed to verify the radiation isocenter using EPID Imaging. The acquired EPID images are transferred to a machine with the IsoTrack Plugin installed.
For more information on Winston-Lutz measurements, see Chapter 10 in the myQA Machines Instructions for Use.
Winston-Lutz Insert in the myQA SRS Phantom
CAUTION NON-INTENDED USE OF WINSTON LUTZ INSERT
The Winston-Lutz Insert for the myQA SRS Phantom / myQA SRS Phantom2 is not intended to be used with Cyberknife or similar treatment machines.
IMPORTANT NOTICE USE A LEVEL TO ALIGN WINSTON-LUTZ INSERT
Use a spirit / bubble level to ensure the proper alignment of the Winston-Lutz Insert after it has been placed in the myQA SRS Phantom.
End-to-End (E2E) Imaging and Planning (I&P) Insert
The E2E I&P insert is used to simulate the whole patient workflow, from CT acquisition to treatment irradiation, including treatment planning and setup in the treatment room. Please see Chapter 10 in myQA Machines Instructions for Use for information.
I&P Insert in the myQA SRS Phantom