Forums Deep Inspiration Breath Hold Auto Beam hold Reply To: Auto Beam hold

Lindsey Fox

We always use auto beam hold for DIBH breast patients. This is nice when someone is borderline out of tolerance and they flicker back and forth across the threshold, our TrueBeam will not only auto beam hold but also auto beam on once they’re back in tolerance. That way the therapist can verbally coach the patient to breathe in a little more and continue treating, without having to beam off, let the patient breathe, get them back in breath hold, mode back up, etc. Of course, sometimes the patient does need a break and will have to free breath for a while before continuing. If someone can’t get back in tolerance, the therapists will re-setup the patient by lining them back up to the free-breathing surface, then get them into breath hold, and if they can’t get quite back into tolerance on the breath hold surface, they will adjust the couch to get them there. We use 3mm/3deg tolerance and we don’t open it up for DIBH patients. This way we know the breast/target is at least within tolerance. If we get a patient that can not reliably repeat the breath hold or constantly struggles to maintain it, then it’s time to talk to the physician about whether or not the patient should be re-planned on the free breathing scan. However, I think this can be avoided with good education, patient practicing the breath hold before sim, consistent coaching (exact same verbal cues) between RTTs, and screening during the sim to determine if the patient can hold their breath for at least 20 seconds (less than that and they won’t make it through a double-exposure portal image.)

We use the same tolerance for APBI, however, we treat those in free-breathing because our physician wants to align those using CBCT, and we’re not confident in the accuracy of AlignRT during a CBCT with the imaging arms out. (If someone knows how to do this, let me know!)