Quality Assurance

A reading list for QA devices

Articles on Detectors

"Dosimetry for ion beam therapy" (2010)

This paper looks at current methods and standards for PBT dosimetry. It also gives advantages and disadvantages of each method. This paper was particularly useful for looking at film dosimetry and ionization chambers. https://iopscience.iop.org/article/10.1088/0031-9155/55/21/R01/meta

"A critical review of the practices of proton daily quality assurance programs" (2021)

https://dx.doi.org/10.21037/TRO-21-11

Commercially Available Devices

IBA Dosimetry

Lynx/Sphinx
- Usage: Daily QA, Monthly QA, Annual QA, Commissioning
- For performing spot size and position measurements and numerous energies.
- 0.4 mm thick and 300 x 300 mm^2 Ga- based plastic scintillator screen, with mirror and CCD camera.
- Technical specs:
  - Pixel size: 4.65 x 4.65 um²
  - Effective spacial resolution: 0.5 mm
  - Video camera: 1024 x 1024, 12-bit resolution
  - Sampling time: 7 images / s
  - Dynamic range can be modified through CCD camera gain settings and lens aperture.
  - Total dimensions 360 x 370 x 600 mm
- Sphinx phantom consists of wedges for range consistency checks for 4 energies (no direct range measurement) and absolute dose measurements with PPC05 Plane Parallel Chamber.
- Used with myQA machine software: myQA Machines Software

Sphinx Compact
- Usage: Daily QA, Monthly QA, Annual QA, Commissioning
- Similar to Lynx detector and Sphinx phantom, but is instead an Silicon flat-panel detector.
- Advertised as being able to complete daily QA measurements in <10 mins.
- Technical specs:
  - 200 x 200 mm^2 flat-panel detector.
  - 0.2 mm spatial resolution
  - 16 bit depth
  - Six different gain values are available: 0.25, 0.5, 1, 2, 4, and 8 pF
- Interval time can be adjusted in 4 steps (100, 200, 400, and 800 ms) - equivalent to dose rates of 0.4 - 4000 Gy/min
  - Approx 11 kg weight.
- Phantom consists of wedges for range consistency checks for 3 energies (no direct range measurement) and absolute dose measurements with PPC05 Plane Parallel Chamber.
- Used with myQA machine software: myQA Machines Software
- https://www.iba-dosimetry.com/fileadmin/user_upload/products/03_proton_therapy/Sphinx_Compact/J_Applied_Clin_Med_Phys_-_2019_-_Rana_-_Development_and_long%E2%80%90term_stability_of_a_comprehensive_daily_QA_program_for_a__1_.pdf

PPC05 Plane Parallel Chamber
- Usage: Daily QA, Monthly QA, Annual QA, Commissioning
- Used with reference class electrometer Dose-X

myQA Phoenix
- Usage: Monthly QA, Annual QA, Commissioning

myQA MatriXX AiR
- Usage: PSQA
- Wireless ionisation chamber array used for planar verification of of patient treatment plans.
- WiFi and battery operation mode available.
- Technical specs:
  - 1521 air-vented ICs
  - 25 × 25 cm² area
  - 6.5 mm center-to-center resolution
  - Minimal sampling time of 20 ms (50 Hz frame rate)
- Reads out 2D dose distribution at different depths using a