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DIBH: CT process

Posted: Mon Apr 29, 2019 7:49 am
by ashleigh_holden
Hi everyone, apologies in advance if this is a stupid question... our AlignRT isn't actually installed yet & still to complete training so I have basic knowledge only.

Does anyone perform CT for breast patients to be treated in DIBH with AlignRT, but without GateCT at simulation? Do you use RPM instead?  Do you have another technique to monitor the reproducibility & stability of breath hold?

Thanks in advance :)

Re: DIBH: CT process

Posted: Tue Apr 30, 2019 6:18 pm
by eoin_callaghan
We now use GateCT at simulation for all DIBH patients. As our AlignRT system went live prior to GateCT install we did sim a couple of patients without the system in CT. In these instances we used our old C-Rad Sentinel system which has similar functionality to GateCT.

VisionRT has initially advised us some centers in the UK using AlignRT did not purchase GateCT. In these centers it was standard practice to use CT lasers to draw lateral marks on the patient at free-breathing stage, encourage DIBH and to look for a vertical displacement of ~1.5cm (1cm minimum). There was no way to monitor stability of breath hold during the CT scan using this technique. We did not feel comfortable using this technique for this reason and continued to use C-Rad Sentinel until GateCT install.

Re: DIBH: CT process

Posted: Tue Apr 30, 2019 6:18 pm
by suzanne_coupland
Hi Ashleigh, we have been using Align RT for our DIBH patients for over a year, and we are awaiting installation of our GateCT in the near future.

We currently use a single camera-based system focussed on the left lateral aspect of the patient. By using the CT lasers and pen marks to mark the height and sup/inf of the breath hold, we ensure that the patient can reproduce the breath hold position prior to scanning, and confirm they relax to the original position on exhalation. Once we are happy with the reproducibility, we mark the lateral laser height along the patients skin to their waistband, so that we can confirm the patient is in the correct breath hold position prior to performing the breath hold scan, which we do immediately following the free breathing scan, instructing them over the intercom.

Hope this helps, Suzanne

Re: DIBH: CT process

Posted: Fri May 03, 2019 2:13 pm
by daniel_vetterli
Hi Ashleigh

yes, we perform CT for breast patients to be treated in DIBH with AlignRT and we do not have GateCT but we are using RGSC (RPM) for monitoring the patient. We take two CT scans, one in free breathing with a low dose protocol for patient positioning and a scan in DIBH. We are using RGSC first for "training" the patient and then to check the stability of the breathing level during the scan. This it all you need and it works just fine.

Hope this helps, Daniel

Re: DIBH: CT process

Posted: Fri May 10, 2019 6:18 am
by sherry_andrew
We use a pressure belt system that we place around the chest at the level of the diaphragm to make sure the patient maintains constant breathold during the CT scan.

Re: DIBH: CT process

Posted: Fri May 10, 2019 6:18 am
by jaime_urribarri
hi Ashleigh

we have developed another technique at my center which we have been using for 7 years. I could send you all the info if you'd like



thx

Jaime

Re: DIBH: CT process

Posted: Fri May 10, 2019 6:18 am
by jaime_urribarri
we have another technique that we had implemented about 7 years ago. it was presented at AAPM 2012

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Re: DIBH: CT process

Posted: Tue May 14, 2019 7:21 am
by nicola_mullins
We have the GateCT installed and it is useful for the pre-scan coaching. It ensures the patient is not releasing breath or slowing gaining air, they can reproducibly hit the same DIBH position and hold it for 20seconds.  I am sure this can be done with other equipment but I can not really comment on that.