Bootstrap Framework 3.3.6

[joshua_naylor]

How long does it take for staff to “unlearn” tattoo-based setup and switch to surface-based setup?

depends on the staff member

i think probably a week or two to get out of the mindset completely on average

[joshua_naylor]

Have any centres used AlignRT to go mask free for H&N patients?

we are testing open face masks at the mo, but we have treated a few people with just a vac bag and no mask monitoring with SGRT. i really like the look of the macromedic head "cradle" the blue part that is moulded to the back of the head so we may try that

[joshua_naylor]

Do patients often move outside of the threshold pausing the beam?

not too often, but it certainly does happen. some patients more than others obviously. if they do move the fairly often move back into tolerance

[joshua_naylor]

How did you increase confidence of staff when moving towards tattoo-less surface-based positioning?

just understanding of how it works and practice. it is pretty self evident how sensitive it is to motion through just a short use

[HelenConvery]

Since the Ct table isn't the same as the couchtop in the linac: can you put a couchmodel in MapRT?

Yes, when VisionRT set up the system for you they create virtual rooms with the linacs in your department, i.e. Varian or Elekta. This includes the couch and the gantry (with and without imaging equipment). They can also make models of any accessories that are used on treatment but not on CT, e.g. the 'couch extension H&N board' used on Varian machines.

[HelenConvery]

Have any centres used AlignRT to go mask free for H&N patients?

We are in the process of moving to shoulderless masks for all patients and using postural video to monitor shoulder position. We are also looking at faceless masks.

[laurence_delombaerde]

Can you comment on what percentage of patients are fully using the AlignRT workflow.

We are using AlignRT for 80% of our patient population. Only for head&neck cancer patients with closed thermoplastic masks we don't use AlignRT (which is about 20% of our patient population). We use AlignRT for our electron patients, although there are exceptions (e.g. on the scalp where there is no visibility).

[laurence_delombaerde]

How does AlignRT tackle center couch during CBCT for DIBH treatments?

For treatment in DIBH where we need to use the center couch we use the following workflow:
1) setup in FB
2) practice the DIBH
3) from the linac console, instruct the patient in DIBH, then perform the center couch shift (in DIBH) and take a new reference after the shift (in DIBH)
4) have the patient exhale and recuperate
5) acquire the CBCT in breath-hold base on the captured reference.

We find that this workflow works well but does require some extra care from the RTTs: we have had patients exhale because of the sudden large couch movement, so RTTs need to provide more instructions to the patient.

[laurence_delombaerde]

Have you ever had to implement set up contingency plans for tattooless patients due to AlignRT failure?

We have set up a contingency plan but we have never had to use it. The basic idea would be: setup patients 'visually' based on photographs we acquire during the CT-sim (e.g. hand position in the arm support). Then we would go to the acquired couch position (we do this for all patients on TrueBeam during the first fraction). Then we would acquire a CBCT and continue on that.

[laurence_delombaerde]

How did you increase confidence of staff when moving towards tattoo-less surface-based positioning?

We initially thought about implementing tattooless incrementally (starting with prostate cases) but then reconsidered as this would possibly create more confusion than it was worth. So instead we had a few information sessions with RTTs (after the decision with a small team was made to go for tattooless). Then we simply stopped tattooing and barely noticed any effect on the linacs...

During our preparation we did an extensive risk analysis to see if there were still parts of our workflow that needed to be adapted. eg. we now place the user origin in fixed locations in the body, and we try to use anatomical reference points such as the bellybutton (in case we would have a breakdown of AlignRT, see my other answer for that).