The following recommendations are taken from the National Breast and Ovarian Cancer Centre's 2008 publication 'Recommendations for use of sentinel node biopsy in early (operable) breast cancer'.
Sentinel node biopsy should be offered as a suitable alternative to axillary dissection for women with:
- tumours equal to or less than three centimeters in diameter
- clinically negative nodes
Sentinel node biopsy is not recommended for women with clinically or pathologically positive nodes.
There are no randomised trial results to support the use of sentinel node biopsy in:
- women with multicentric / multifocal tumours
- pregnant or breastfeeding women
- women with known allergies to radioisotopes or blue dye
- women with previously treated breast cancer or axillary
- surgery on the affected side
Information about procedures should be discussed with the patient. The patient should be adequately prepared for the procedure. For sentinel node biopsy this includes:
- a clear description of sentinel node biopsy
- clear information about the objective of the procedure
- the potential of an unsuccessful sentinel node biopsy or
- false negative result
If the sentinel node is identified at the time of sentinel node biopsy:
- for a positive sentinel node—axillary dissection is recommended (with due consideration of the risks and benefits to the individual woman)
- for a negative sentinel node—clinical follow-up of the axilla is recommended
If the sentinel node is not identified at the time of sentinel node biopsy:
- axillary dissection should be performed
The outcome of women with breast cancer is better if they are treated by a clinician who has access to the full range of treatment options in a multidisciplinary care setting.
The team for performing sentinel node biopsy should comprise a surgeon, nuclear physician (where nuclear medicine facilities are available), pathologist, anaesthetist and appropriate nursing support throughout and following the procedure.
Ongoing data collection and audit of sentinel node biopsy performance by the team should be conducted.
The surgeon performing sentinel node biopsy should be appropriately trained and experienced in the sentinel node biopsy techniques and have evidence of successful identification of sentinel node(s).
The Australian SNAC I protocol states the surgeon performing sentinel node biopsy should have completed sentinel node biopsy in at least 20 consecutive cases with a greater than 90% success rate in locating the sentinel node(s).
Where possible, lymphatic mapping with pre-operative lymphoscintigraphy in combination with intraoperative use of the gamma probe and blue dye should be used to locate the sentinel node(s).
Where combination technique is not available or suitable, use of blue dye or radioisotope alone is an appropriate option.
Blue dye alone could be used where no nuclear facilities are available; however, the individual surgeon’s sentinel node biopsy technique and results should be audited.
Trial results do not indicate that any site of injection (peritumoural, periareolar or intradermal) is superior in detecting the sentinel node(s) in the axilla.
Dr Gault uses a combination of Peritumoural injection or Lymphoscintigraphy and sub-areola blue dye injection.
All identified sentinel nodes should be excised, including non-axillary sentinel nodes, if they can be accessed and excised without increased morbidity.
False negative rates
To reduce false-negative rates, surgeons should aim to remove all identified sentinel and/or clinically suspicious nodes at the time of surgery.
However, removal of four or more nodes from the axilla can increase risk of morbidity, and does not lower the false negative rate significantly compared with removing up to three nodes.
Detailed, definitive histological assessment (including immunohistochemistry and serial sectioning) of the sentinel node is recommended for the detection of metastatic disease.
Intraoperative assessment of the sentinel node may be performed, allowing those cases identified as positive for metastatic disease to proceed to immediate axillary dissection as a single procedure.
Intraoperative assessment should be confirmed with detailed, definitive histological assessment.
Surgeons and anaesthetists should be aware of the possibility of adverse reactions (including allergies) in patients and, in the event of an adverse reaction, agreed protocols should be in place.
When sufficient evidence does not exist to guide definitive recommendations for the use of sentinel node biopsy, if possible, patients should be offered entry into properly conducted clinical trials where indicated and/or appropriate.
For more information visit the Cancer Australia website.