Sentinel Lymph Node Biopsy (SLNB)
In the situation of a mouth cancer being at risk of spreading microscopically to the lymph glands in the neck but with no evidence on imaging, some are advocating a SLNB as a potentially less invasive procedure than an Elective Neck Dissection.
In SLNB a special tracer dye is injected in to the tumour in the tongue and with imaging and a hand held probe, the surgeon is able to identify the first lymph glands in the chain which would show potential cancer spread. The aim is to reduce the extent of the surgery required.
Once the sentinel lymph node has been removed it is sent to the pathologist for analysis. This can take around a week. If the node is positive then patients usually require a second operation – a completion neck dissection.
The issues around the decision making process are complex and should very much be tailored to individual patients. It should be borne in mind that Sentinel node biopsy has a false negative rate, and represents a departure in terms of safety from the gold standard of the elective neck dissection. Our surgeons are fully experienced in both procedures and would be happy to take the time to explain what is involved and help you as an individual reach the best decision.
An appointment would be made the day before your procedure for injection of a radio colloid tracer in and around the tumour. Following this a special nuclear medicine scan is performed which helps the surgical team identify and locate the sentinel node. Surgery is carried out under general anaesthetic, at the start of the operation a blue dye is injected in to the tumour. This blue dye passes through to the sentinel node.
A neck incision is made in a similar way to a selective neck dissection to provide access to the lymph glands.
The combination of the blue dye technique and radioactive colloid means that the surgeon can locate the sentinel node by its appearance as well as the signal obtained from a handheld probe which increases the accuracy.
Once the node (or often several nodes) have been removed, then the wound is carefully closed.
In essence the risks for SNB are similar to those of a selective neck dissection described above.