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Sentinel Node Biopsy : the way forward. Hemant Singhal MS FRCSEd FRCS(Gen) FRCSC Consultant Surgeon Northwick Park & St Marks Hospital Senior Lecturer, Imperial College School Of Medicine.
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Sentinel Node Biopsy : the way forward Hemant Singhal MS FRCSEd FRCS(Gen) FRCSC Consultant Surgeon Northwick Park & St Marks Hospital Senior Lecturer, Imperial College School Of Medicine These PowerPoint presentations are free to download only for academic purposes, with due acknowledgements to authors and this website.
Introduction • Who should have it • When • How • Who will do it • What can we hope to achieve HEMANT SINGHAL
Background • 95% of patients who present with breast cancer have apparently local disease. • Indirect features to suggest systemic involvement • axillary lymph node metastasis • tumour size, grade • vascular or lymphatic invasion • Her2neu status or p53 etc HEMANT SINGHAL
Preoperative evaluation of axilla • Clinical examination inaccurate, false negative rate of 39-45% • Mammography/ultrasound • sensitivity of 70% • CT • MRI • PET • Ultrasound guided FNAC HEMANT SINGHAL
Rationale for axillary surgery • Status • Local control • Survival impact (B04) study • 10 years 5-6% worse • There is no tumour size so small that one can ignore the axilla • upto 20% for T1a HEMANT SINGHAL
Issues with axillary clearance • Maybe of limited therapeutic value • 80% of patients maybe LN negative • Short term drains, seroma • Lymphoedema • Sensory loss in area of ICB • affects the lifestyle of a third HEMANT SINGHAL
Sentinel node concept • Ramon Cabanas • coined the term • lymphatic drainage in ca penis • Donald Morton: malignant melanoma HEMANT SINGHAL
Sentinel node concept • First draining lymph node • reflects the status of the axilla • can be identified and sampled HEMANT SINGHAL
SENTINEL NODE CONCEPT • sentinel node refers to the "node on watch.” • this node is the first node to receive cancer cells and that if this node is positive, there may be other positive nodes upstream. • The cancer cells don't "skip" and go to higher nodes. • If this node is negative, all the upstream nodes are negative 99 out of 100 times HEMANT SINGHAL
After a crime, you don't interrogate a bunch of people who were two blocks away; you focus on eye witnesses at the scene of the crime." —Marisa Weiss, M.D. HEMANT SINGHAL
Collective experience • ACS study ~ 5000 patients • ALMANAC ~UK study • 18 other sizeable studies • 88% LN detection • 98% accuracy • 7 series with 100% results HEMANT SINGHAL
Nuclear medicine aspects • Amount of radioactivity • dose of 0.1 mCi for same-day and 0.4 mCi for day-before injection • Preop scintigram • useful initially • know that there is a localised SNB • abnormal pattern - Rotters, IM, breast HEMANT SINGHAL
Site of injection • SLN identified by • intraparenchymal • subdermal • intradermal • subareolar injections HEMANT SINGHAL
Surgical aspects • Identify blue lymphatics • track hot node • intraop palpation for involved node • gross disease can block localisation HEMANT SINGHAL
Inaccurate results • The scenario of a negative (non-cancerous) sentinel node and positive (cancerous) additional nodes in a patient can occur for several reasons, including: • The timing of the dye injections • The type of dye/tracers used • The presence of more than one sentinel node • The way in which the initial node was sectioned or stained in the pathology lab HEMANT SINGHAL
Poor candidates • palpable lymph nodes • Locally advanced breast cancer • multi-focal breast cancer • previous breast surgery (including breast reduction) • previous radiation therapy to the breast HEMANT SINGHAL
American College of Surgeons recommends • at least 30 snb followed by complete axillary node dissection, • with an 85% success rate in identifying the sentinel lymph node(s) • and a 5% or lower false positive rate. HEMANT SINGHAL
Tips & Tricks • Map with probe • 3D mental map • Allow adequate time after blue dye inj • LN is invariably lower than you think • Persevere HEMANT SINGHAL
Can we stop after negative SNB • Axillary relapse, most studies have median FU that is too short • melanoma about 3-4% • expect 1% for breast • 0.4% at median fu of 84 months Singhal 1996, MSKCC HEMANT SINGHAL
Should you go back after SNB+ • 39% have further involved nodes • this may be obvious at first op • intraoperative analysis • cytology 10% false negative • frozen section HEMANT SINGHAL
The important question • "HOW MANY lymph nodes are positive?" • not just "ARE lymph nodes positive?" HEMANT SINGHAL