Commissioning and QA

Question 1

Procedure for IMRT Commissioning

Answer 1

1. Acceptance Test All equipment
2. Network Links - IS
3. Beam Data Collection: PDD, Profiles, Output factors
4. TPS Beam modeling
5. Test IMRT dose algorithm
6. Test Optimization algorithm
7. MLC Commissioning
8. R and V System testing
9. Delivery System

Question 2

What is the flow for IMRT pt specific QA?

Answer 2

1. MU Check
2. Absolute Dosimetry (ion chamber - gold standard)
3. Relative Dosimetry (film - gold standard)
4. Staff Education

Question 3

What does the AAPM allow for total deviation for Rx (absolute dosimetry)?

Answer 3

+- 5% (3% is preferred)

Question 4

What does relative dosimetry measure, what is the tolerance?

Answer 4

Evaluation of profiles; 3-5%