Blue dye is often used in combination with Tc99m marking of SLN. Its limitation (similar to ICG marking) is its limited depth penetration. This means for targeting of the SLN there must be a direct visual contact. Literature shows that a combined marking of blue dye and Tc99m using radio-guided surgery has the highest success rate and lowest false negative rate in the removal of the SLN. Blue dye needs direct access through invasive procedures and does not facilitate any targeting and orientation before the incision started, resulting in a more invasive, manual search for the SLN.

Blue dye is also limited to anatomical marking of the SLN and thus cannot be applied to any primary tumor marking and resecting.

declipseSPECT is a 3-D intra-operative SPECT imaging and navigation solution. Technically declipseSPECT is an extension of gamma probes by a navigation system. The same functionality and workflow as using gamma probes can be maintained using declipseSPECT. When using a gamma probe the surgeon has to manually create a picture of the activity distribution in her/his mind and apply this to the access and removal of the labeled tissue. When using declipseSPECT the 3-D image of radioactive concentration and distribution is created by the system and visualized for guidance enhanced by additional depth information. declipseSPECT thus extends the functionality of a gamma probe for safer and more reliable procedures, guiding the removal in complex cases where fine navigation through critical anatomy is required. Also the differentiation of close structures or SLN in close vicinity is possible since declipseSPECT can eliminate "shine-through" effects of the gamma probe alone detection.

Planar 2-D projective images of radioactivity usually have a good lateral resolution, however lack occlusion in the 3rd dimension and have no depth information. Despite the 2-D vs. 3-D nature of the images, the surgical task is not supported by images alone but by image guidance, support to pinpoint the lesion. This is very limited in only two dimensions and without any anatomical correlation. Our 3-D solution features images in all dimensions and provides a direct correlation with the anatomy, not only for image viewing, but also for localization and targeting of structures by means of image guidance during surgery.