How does lymphoscintigraphy work?
Lymphoscintigraphy works based on the radio tracer that we inject. The radio tracer is basically very small particles, which are labeled with radio activity. These particles are taken up by the lymphatic system, these are lymphatic cells, whose function is to take up these particles and engulf them, and take them out. Then the lymph cells travel along the lymphatic channel to the lymph nodes, and as they travel and accumulate in the lymph nodes, we see an accumulation of the particles that we initially injected around the tumor. That's how we see the drainage pattern of the tumor, because it's basically giving us a map of the pattern, which is very important for the surgeon to know where to look. For example, if a patient has breast cancer, lymphoscintigraphy is performed, and finally we find a lymph node that has accumulated the radio tracer. That's called a sentinel lymph node, the first that accumulated this radio tracer. The surgeon can find that lymph node, both through imaging and also what we call a gamma probe, by putting a probe over that specific lymph node where the radioactivity is the highest, and then they take that lymph node out and give it to surgical pathology to look for metastasis in the lymph node. If there are metastases in the lymph node, the treatment is different from when the lymph node has no evidence of metastasis. So in this sense lymphoscintigraphy is really contributing in giving a roadmap to the surgeon.
