Breast sentinel lymph node injections are commonly done before surgery for breast cancer. The sentinel lymph node injection allows the surgeon to limit the amount of surgery to the sentinel lymph node in the arm pit instead of multiple nodes. This lowers the risk of subsequent complications.
The sentinel lymph node injection is done in the radiology department, often in the nuclear medicine section. A properly trained technologist will prepare the dose of radiopharmaceutical for the radiology physician to inject. Some lidocaine or numbing medicine is mixed with the radiopharmaceutical in our department. This is to make the injection less painful.
After the procedure is explained and all questions are answered, I clean the skin in the area of the breast to be injected. The needle used is very small and thin. This is smaller then the needle for breast biopsies. I usually inject under the skin by the nipple. There are other methods used by some radiology physicians but all of them work.
As far as pain, I find that the majority of women are pleasantly surprised at how little pain or discomfort they feel. The needle going into the skin may feel like a pinch, but many women feel very little after that. Some women may feel discomfort but this subsides once the numbing medicine starts to work.
I almost never see any problems with the injection or after. There are almost never complications and the procedure is very well tolerated. Some patients will take a nerve relaxant prior to the procedure. I have seen others meditate or think about pleasant imagery. Other patients are comforted by a supportive technologist. So in the majority of cases, I would call this a very well tolerated procedure with most patients being pleasantly surprised afterwards. The worst part in my experience, is the anticipation of the procedure.