These 46 surgeries resulted in 52 pre-incision and 48 post excision Freehand SPECT scans. This is due to the fact that some patients have undergone SLNB in more than one body region (e.g. bilateral breast cancer, vulvar cancer or some cases of melanoma). The different counts of the pre-incision and post-excision scans are due to the time constraints in the OR and also due to the technical and practical problems encountered in between. Furthermore, in some cases the measurement with the gamma probe was enough for the surgeon to make sure that there is no more activity left in the region of interest and therefore the post-excision scan was not necessary.