SGRT Forum

So we have a case with a patient with a very large pendulous breast that we are trying to troubleshoot to see if we can use VRT to help with set up. When she is laying supine, her breast falls to her lateral side, so much so that we are worried that it would block the area we would normally use to draw our ROI. In the past prior to VRT, we've used a bra a help hold the breast in place and help recreate the set up. We understand this wouldn't work with VRT. I've seen the ROI drawn with the unstable part of the breast omitted from the ROI and just the more stable aspects of the surrounding breast tissue and chest wall included, however I don't think that would be effective in this case. There is a good chance that this is simply not a case that we can use VRT to set up with, however, if anyone has any recommendations, tricks or ideas that they might be using or have used we are open to suggestions.

Thanks!

Jen R

Hi Jen,

We use AlignRT on all our breast patients and have found the system extremely useful for large pendulous breasts.  We do treat on a breastboard, normally on an incline of about 12.5, and this does help the breast to fall inf as well as laterally.  I would go ahead and draw your ROI to cover the entirety of the breast tissue, and see how you go on fraction 1.  You can always amend your ROI with the patient on the bed too to include more or less.  Perhaps just allow her an extra 5mins on Day 1.  If you want me to have a look at the ROI you draw just post it on here, without any identifiable patient data on there.

Let me know how you get on

Jacqui

Hi Jen

We use tilted breast board and upside-down t- shaped ROI for all of our resection (n0) breast patients. In our small clinical study of ten patients we found that the upside- down t- ROI (does not include diaphragm, includes small portion of both breasts) correlates best with the entire bony chest wall position (achieved in the online match). Based on larger study, the realized setup margin needed for the soft tissue was around 5 mm with that ROI (n=25). The ROI which covered the whole breast caused larger random errors in the LNG isocenter and ROLL in comparison to bony online match (compromise match between sternum and the ribs in the middle of the PTV in LNG,LAT,VRT), correlating with the daily position variation of the soft tissue. Nothing else statistically significant was found between the ROIs, so I can not much argue with users which draws plenty of soft tissue into ROIs. Some may create a full publication of this, take a catch:). Do you want to roll the entire patient in the setup, based on the roll which comes from the roll of the soft tissue, or how do you know is the whole patient rolled or just the soft tissue with the whole breast- ROI? In your case I could do an additional ROIs, one for the soft tissue and one for the rigid structures to see how much they differ in the setup or setup the patient with upside-down t-ROI and acquire treatment capture to see the position of the soft tissue. Can that colour view- feature be useful? In our current practice we finally verify the location of the soft tissue with the tangential images and it should be inside 1 cm and inside treatment field. In VMAT- treatments we acquire CBCTs and want the soft tissue to locate exactly at the planned position, mostly in other cases the margins covers the daily variation of the soft tissue after bony match. If not, finally re-planning may be needed. Your solution depends on the ideology to treat the breasts.

Regards Marko

For large breasts you can CT the patient as you feel is best suited for treatment and then during import create two separate ROIs. For large breasts the first ROI can be the ROI without the pendulous portion of the breast included but include over midline grabbing the clavicular heads and the medial aspect of the contralateral breast for extra features for setup. The second can be smaller and more like the typical ROI including the breast tissue.

During setup you can setup using the first ROI to get the chestwall and general anatomy in the proper location then switch to the second ROI. When you switch to the second ROI you will most likely see a shift in the position due to the effects of the pendulous portion of the breast but now you move the breast to the ROI instead of the whole patient to the ROI. This allows you to do both patient positioning and setup as well as ensure the breast is in the field as intended each day. You can easily swap between ROIs in the software to make sure the breast stays stable during delivery. This has worked well for us when the patient isn't a candidate for prone breast treatment.

We have started to use the Civco Radiation Bra for large pendulous breast still using a breastboard.  The bra lifts the inferior portion of breast and has been successful eliminating lateral folds. Civco is currently improving the bra to give more support and larger cup sizes for plus sized patients. Added bonus, OSMS can be used for setup and treatment. You can draw an ROI over the mess material of bra just like a breast without the bra.  I would be happy to share more if needed.