Sentinel Lymph Node Biopsy

In an effort to minimise the morbidity (arm swelling, stiff shoulder and altered sensation) associated with standard axillary surgery contemporary practice is moving towards identifying and removing only the key (or sentinel) nodes.

Many international studies* have shown the sentinel node can be correctly identified in 95% of cases and, if clear of tumour, the likelihood of any other (i.e. non-sentinel) nodes being involved is less than 5%. Depending on your particular circumstances SLNB may be recommended as an independent procedure or as part of a formal axillary dissection, where it has the advantage of allowing closer pathological review of the crucial lymph node/s.

Such sensitivity involves a combination approach with both blue dye and a radioisotope injected around the tumour. The overall radiation involved is less than one chest X-ray and the vast majority of the dose is removed with the tumour and any residual activity is depleted within 36 hours of surgery. The blue dye used can stain the skin leading to a temporary tattooing effect, which can last for weeks or even months. Urine can also be tinged with blue for several hours after surgery. Cases of allergic reaction to the blue dye have been reported very rarely. If the sentinel node/s are positive on intraoperative cytology/frozen section a standard axillary dissection will be undertaken immediately. If the cytology/frozen section is clear/unavailable but the final pathology is positive a further operation to remove the remaining lymph nodes will be recommended. This will take place a week or two later. 

*: Technical outcomes of sentinel-lymph-node resection and conventional axillary-lymph-node dissection in patients with clinically node-negative breast cancer: results from the NSABP B-32 randomised phase III trial. Krag DN, et al Lancet Oncol. 2007 Oct;8(10):881-8.