If lymphoscintigraphy is performed in both breasts, I report 78195 and A9520 x 1 each. Code 78195 has a medically unlikely edit (MUE) of 1. A9520 is per study dose, but bilateral breasts are considered one study, not two. However, if both breasts are injected but imaging is not performed, I report 38792 x 2 and A9520 x 1. I don’t understand why they aren’t reported the same number of times. Can you explain?
Lymphoscintigraphy (78195) can be limited area or whole body, and it is one exam no matter how much you image. If the imaging is performed prior to the patient going to surgery and for sentinel node injection, it doesn’t matter—what you did is one imaging exam and the injection for imaging is included, so even though you give two injections, it is one exam.
On the other hand, when injecting for the sentinel node without imaging, each breast has a separate sentinel node and so you code two injections and two doses. It is much more common to just do one breast.