Radiotherapy QA Flashcards
What is the suspend tolerance for Gantry Rotation?
+/- 0.5deg
What is the suspend tolerance for light field size?
+/- 2mm (field size at isocentre)
What is the suspend tolerance for radiation output (absorbded dose to water per MU)?
+/- 3%
What is the suspend tolerance for Beam flatness and symmetry?
+/- 3% baseline profiles
What checks are likely to be part of monthly QA?
Photons
- output
- energy
- flatness and symmetry
electrons
- output
- energy
- applicator output factors
- flatness and symmetry
mechanicals
- cross-wire set up
- light field set-up
- LASER alignment
- jaw calibration
- couch movements
What is the suspend tolerance for radiation output (absorbed dose to water per MU)?
+/- 3%
What is the suspend tolerance for beam energy (TPR-20/10)?
+/- 1.5%
What is the suspend tolerance for Beam flatness and symmetry?
+/- 3% baseline profiles
What checks are likely to be part of monthly QA?
Photons
- output
- energy
- flatness and symmetry
Electrons
- output
- energy
- applicator output factors
- flatness and symmetry
Mechanicals
- cross-wire set up
- light field set-up
- LASER alignment
- jaw calibration
- couch movements
What are the mechanical uncertainties that come from a Linac?
- Jaw calibration
- Light-field coincidence
- Laser alignment
- Collimator rotation
- Gantry rotation and sag
- Table movements (3-axes and rotation
What is the suspend tolerance for a Linac LASER?
+/- 2mm
What is the suspend tolerance for collimator rotation?
+/- 0.5deg
What is the suspend tolerance for couch movements?
+/- 2mm
What is the suspend tolerance for couch rotation?
+/- 0.5deg
What is the suspend tolerance for radiation field size (jaw calibration)?
+/- 2mm (field size at isocentre)
