To Have IORT or No Rads

I can't answer the IORT question but I have a question for you. 

If you are having a lumpectomy, what's the rationale given by your surgeon for having the Sentinel Node Biopsy?  That's not usually recommended for women who are having a lumpectomy for pure DCIS.  If it should turn out that some invasive cancer is found, an SNB can be done afterwards.  But with pure DCIS, it's not medically necessary to check the nodes, and any node removel exposes you to a lifelong risk of lymphedema.  Have you discussed this with your surgeons and made a conscious decision to have the SNB or is it just something that your surgeon suggested (some surgeons continue to do SNBs when they do lumpectomies regardless of the diagnosis).

Kat, DCIS cannot travel to the nodes.  So it's only if some invasive cancer is found with the DCIS that it becomes necessary to check the nodes.  If you were having a mastectomy, then it would make sense to have the SNB, since it is difficult to do an SNB after a mastectomy (the process involves injections made into the breast, and once the breast is gone....). So if a MX was done and some invasive cancer was found, and if an SNB hadn't been done, then a more extensive axillary node dissection would be necessary.  So usually the choice is to do an SNB as a precaution when the surgery for DCIS is a MX.  But with a lumpectomy, there is really no reason why an SNB needs to be done because it can always be done later should any invasive cancer be found.  Being overweight shouldn't be a factor. 

Here is a link to the NCCN Treatment Guidelines for Patients, Breast Cancer.  http://www.nccn.com/files/cancer-guidelines/breast/index.html#/60/

The information about DCIS starts on page 61.  These are the same guidelines used by most surgeons in the U.S..  You can see at the top of page 62 that it states that "Lymph node surgery is generally not done with DCIS".  In the next sentence, when they refer to situations where an SNB might not be possible after some surgeries, they are referring to mastectomy surgery.

Many doctors downplay the possibility of lymphedema after a sentinel node biopsy but the risk is actually not insignificant.  Additionally, once someone has had nodes removed, they often choose to take precautions with the use of that arm - no blood draws, no blood pressure, extra care to not get an infection.  So even if you never develop lymphedema, having an SNB can have an affect.  I don't have lymphedema, but I am always cautious about my right hand and arm. 

For someone who has invasive cancer, having an SNB is a necessary risk, but that's just not the case for someone who has DCIS and who is having a lumpectomy.