What QA steps are done at the treatment machine before commencing a new course of radiation treatment on a particular patient? Are these steps any different for complex treatments such as IMRT or multi-beam 3DCRT?
QA Steps for 3DCRT
There are numerous aspects of a plan that are checked in the treatment room prior to a patient commencing treatment. These include:
- Ensuring that the plan has been reviewed and accepted by a radiation therapist, the head of planning, and the radiation oncologist involved
- Ensuring that the required equipment and accessories are present in the bunker, and that they correspond with the treatment plan
- Ensuring that the prescription recorded by the radiation oncologist matches the treatment plan for the patient
- For complex plans (such as head and neck treatments), a mockup session may be conducted before treatment begins. This allows acquisition of kV imaging in the correct positions as well as drawing guides on the thermoplastic mask.
QA Steps for IMRT
IMRT requires additional QA steps to ensure accurate and safe treatment is delivered. This typically includes a treatment using a patient phantom, which allows medical physics staff to model the actual dose distribution produced by the plan.