Bootstrap Framework 3.3.6

[Charlotte_McAlinden]

Hi,

Is anyone using CBCT imaging for breast DIBH patients? We currently CBCT all breasts and use the RGSC system for DIBH which will automatically beam hold the CBCT if they were to move out of breath hold (we spilt the CBCT into 3 manageable chunks anyway). Do you have any issues with patients moving out of breath hold thresholds and the CBCT continuing or any ways of managing this? It seems a step back for us to not have the automatic beam hold for CBCTs on these patients.

Any experiences or thoughts would be greatly appreciated.

[laurenvacker1]

Curious as to what the RGSC system is?

[schang1]

Our preferred method is the partial arc cone beam at the treatment isocenter (not centering the couch), which allows patients to complete imaging in less than 35 seconds during a single breath hold.

[Laressa Priddy]

Hi schang1

Please can you share how you are able to do partial arcs CBCT without couch centre for breast patients? We have always found that the gantry collides with patient arms/couch.

[GeorgeG]

I'd also be interested to hear how you do the partial CBCTs without centering the couch please. We use Varian Truebeam.
Thanks
George

[schang1]

We only perform DIBH CBCT for Breast/Chest Wall treatments when using the VMAT/IMRT technique. For this, we use a breastboard with a 5-degree tilting angle and a VacLok on top of it. Additionally, we use a 5-cm shifting index bar to ensure the tabletop is as central as possible. The isocenter is positioned in the lung beyond the chest wall and is less than 24 cm vertically to the tabletop. The 200-degree partial arc CBCT begins at gantry 179 degrees to enhance AlignRT visualization. I hope this helps.

[Laressa Priddy]

Thank you for sharing that's really helpful.