QA

Question 1

why is it important?

Answer 1

• right radiation quality (beam energy, filtration)
• right treatment position
• safety: interlocking systems, electrical

Question 2

what is the frequency of the tests dependent on

Answer 2

their complexity

Question 3

what are the daily tests?

Answer 3

carried out by the radiographer, confirming that the machine is working correct

Question 4

what does C-RAD require

Answer 4

morning tests before being used

Question 5

who carries out the monthly/ annual tests

Answer 5

clinical engineers and medical physics

Question 6

what are the accepting tests

Answer 6

• initial tests when items are bought
• must conform to specifications
• radiation beam quality
• physical movements
• electrical safety
• radiation surgery
• inventory of radiotherapy unit

Question 7

what are the clinical engineering tests

Answer 7

equipment: water phantom, material

Question 8

what is the water phantom equivalent to

Answer 8

tissue

Question 9

why is a water phantom used?

Answer 9

so it can calculate and monitor doses

Question 10

what are the commissioning tests

Answer 10

• prep equipment ready for clinical use
• tests (F)
• radiation protection: treatment room and equipment
• accuracy of all beam direction devices
• in depth dose measurements
• all data is recorded
• data for planning: dose calibration, software training

Question 11

what is the % that the backup timer can run over by?

Answer 11

1% if it goes over this it can’t be used

Question 12

what is the dosimetric output check

Answer 12

over 105

Question 13

what happens if equipment reaches over action level

Answer 13

the equipment is removed

Question 14

what are the daily tests:

Answer 14

• patient monitoring audiovisual
• door closing mechanism and interlock
• couch movement and breaks
• treatment unit function/ motion and stop
• interlocks for the door, beam hardening filters, kv energy selection
• beam status indicators
• beam off at key off test
• emergency off test
• KV and mA indicators
• back up timer/ monitor unit check 1% (tolerance), 2% (action)
• dosimetric test: output check 2% (tolerance), 4% (action)

all these are functional

Question 15

what are the monthly tests:

Answer 15

• daily tests (F)
• mechanical safety and stability
• accuracy of treatment head tilt and rotation readout
• applicator tests 10% (tolerance), 15% (action)
• beam quality: HVL 15% (tolerance)

Question 16

how is HVL checked

Answer 16

it is measured over a range of thicknesses, with it being applied adjacently over the applicator

Question 17

what are the annual tests:

Answer 17

• focal point alignment (reproducible)
  the CA must hit the centre of the target, if the alignment was to change it could change the aperture which may not permit the axis. A miss alignment could cause the radiation to hit an unprescribed area