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

List of 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
• 0.6 mm plate spacing, 9.9 mm diameter, and a 3.4 mm guard ring
• Used with reference class electrometer Dose-X
• Multiple use cases:
  • Daily QA - used with Lynx/Sphinx or Sphinx Compact inside phantom wedges for machine output verification.
  • Within standard solid water phantom for dose output verification.
  • Used within Blue Phantom PT (https://www.iba-dosimetry.com/product/blue-phantom-pt) for absolute dose measurements and depth dose profiles in a water phantom.

myQA Phoenix

• Usage: Monthly QA, Annual QA, Commissioning
• High-resolution amorphous silicon digital detector array.
• Capable of single shot and movie mode measurements.
• Technical specs:
  • 2048 × 2048 (4,194,304) pixels.
  • 0.2mm resolution.
  • 1 frame/sec with 65536 counts/frame sampling frequency.
  • 582 × 522 × 31 mm³
  • 13 kg
  • Fast ethernet communication
• Comes with foot stand & alignment bar for quick setup.

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
  • Minimum sampling time of 20 ms
  • Detector dimensions: 57.6x32x4cm
  • 7.3kg weight (inc battery)
• Reads out 2D dose distribution at different depths and gantry angles using miniPhantom R & Gantry Sensor+.
• Compatible with protons and carbon ions.
• conformalFLASH ready
• Compatible with DynamicArc (proton arc therapy) using gantry angle sensor and rotating holder.

Giraffe

• Usage: Monthly QA, Annual QA, Commissioning
• A high resolution multi-layer ionisation chamber for single-shot pristine Bragg Peak measurements.
• Technical specs:
  • 180 12 cm diameter electrodes.
  • 33cm WET energy range.
  • +/- 0.5mm WET range accuracy.
  • 2 mm detector native spatial resolution (can be improved by applying Bortfeld fit).
  • Dose rate range: 0.5 Gy/min to 15 Gy/min
  • Signal to noise ratio: max. 0.2 % with 1 cGy integrated dose
  • Dose linearity: max. 0.5 % from 10 cGy up to 5 Gy integral dose and max. 1 % from 0.5 Gy/min up to 15 Gy/min dose rate
  • 180 channels
  • Min 10ms sampling time
  • Weight: approx. 10 kg
  • Dimensions: 43.9 cm (L) x 19.5 cm (H) x 17.5 cm (W).

Zebra

• Usage: Monthly QA, Annual QA, Commissioning
• A high resolution multi-layer ionisation chamber for single-shot pristine Bragg Peak and SOBP measurements.
• Technical specs:
  • 180 2.5 cm diameter electrodes.
  • 33cm WET energy range.
  • +/- 0.5mm WET range accuracy.
  • 2 mm detector native spatial resolution (can be improved by applying Bortfeld fit).
  • Dose rate range: 0.5 Gy/min to 15 Gy/min
  • Signal to noise ratio: max. 0.2 % with 1 cGy integrated dose
  • Dose linearity: max. 0.5 % from 10 cGy up to 5 Gy integral dose and max. 1 % from 0.5 Gy/min up to 15 Gy/min dose rate
  • 180 channels
  • Min 10ms sampling time
  • Weight: approx. 10 kg
  • Dimensions: 43.9 cm (L) x 19.5 cm (H) x 17.5 cm (W).

StingRay

• Usage: Monthly QA, Annual QA, Commissioning
• Large diameter integral ionisation chamber for proton therapy PBS dose measurements.