HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH RSS TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) CME Activity Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mariani, G. Articles by Paganelli, G. Search for Related Content PubMed PubMed Citation Articles by Mariani, G. Articles by Paganelli, G.

Radioguided Sentinel Lymph Node Biopsy in Breast Cancer Surgery*

Nuclear Medicine Service, Department of Internal Medicine and Medical Specialties, University of Genoa Medical School, Genoa; Division of Surgical Oncology, Department of Oncology, Biology and Genetics, University of Genoa and National Cancer Institute, Genoa; Division of Surgical Oncology, National Cancer Institute, Genoa; Department of Pathology and Division of Nuclear Medicine, European Institute of Oncology, Milan, Italy; Department of Nuclear Medicine, Royal Free Hospital and School of Medicine, London, United Kingdom; and Division of Nuclear Medicine, Department of Radiology, Stanford University School of Medicine, Stanford, California

View larger version (31K): [in a new window]   FIGURE 1. Schematic conceptualization of sentinel lymph node. Being first node encountered by lymph draining from primary tumor, sentinel lymph node should be site where clusters of tumor cells migrating through lymphatic channels are most likely to be entrapped and possibly proliferate before widespread tumor dissemination in body. Second-tier (or second-echelon) lymph nodes receive lymph (and possibly tumor cells) from sentinel lymph node and in turn drain lymph toward third-tier lymph nodes.

View larger version (55K): [in a new window]   FIGURE 2. (A) Schematic representation of structure of cutaneous blood and lymph vessels. For simplicity, blood and lymph vessel networks (which are intimately embedded in each other) are represented separately on left (red and blue) and on right (yellow). Embryologic origin in ectoderm places mammary gland in ideal space between subcutaneous plexus and deep lymphatic collectors (emphasized in figure). Each branch of periductal plexus drains lymph mostly toward skin surface (through subareolar plexus), whereas minor component drains toward deep collectors (draining in turn toward internal mammary chain). Radiocolloids injected intradermally over mammary gland drain to subcutaneous plexus, which is also terminal pathway of predominant lymph drainage from mammary gland. (B) Schematic representation of pathways of lymphatic drainage from mammary gland (modified from (150)). Most lymph produced in mammary gland surfaces at subareolar plexus, then merges with subcutaneous plexus of overlying skin, and flows with centrifugal pattern mostly toward axilla. Lymph from deeper portion of gland drains either through same pathway or through deep lymphatics to reach parasternal, internal mammary chain (and even contralateral side). abdom. = abdominal.

View larger version (55K): [in a new window]   FIGURE 3. (Left) Red dots symbolize radiocolloids migrating with afferent lymph from site of interstitial injection to lymph node, where they are entrapped by macrophages lining sinusoid spaces (red area). (Right) Low-magnification histoautoradiograph of sentinel node removed about 20 h after injection of 99mTc-HSA nanocolloid. Black dots (silver grains) show retention of radioactive agent in sinusoid spaces. (Hematoxylin–eosin, about x8)

View larger version (25K): [in a new window]   FIGURE 4. (A) Time–radioactivity curves from region-of-interest (ROI) analysis after dynamic recording of lymphoscintigraphy performed by intradermal injection of 6 MBq (150 µCi) 99mTc-HSA nanocolloid; y-scale is arbitrary to plot all 3 curves within same order of magnitude. Injection site shows minimal reduction over 60 min, barely discernible from physical decay. Tracer appears in sentinel node starting few minutes after injection, with quasiplateau maintained over 60 min. Lymphatic channel shows early passage of radioactivity, continuing with quasipulsatile pattern. Direct supply of radiocolloid draining from injection site (continuing over several hours) keeps radioactivity content of sentinel node at relatively higher level than that of second- or third-tier nodes, even if active retention of tracer by macrophages is saturated. (B) Definition of 3 ROIs on representative frame set from dynamic recording: ROI 1 = injection site; ROI 2 = lymphatic channel; ROI 3 = sentinel node.

View larger version (17K): [in a new window]   FIGURE 5. Scintigraphs obtained in right anterior oblique view 15 min after subdermal injection of radiocolloids with different particle size: 99mTc-sulfide (left), 99mTc-HSA nanocolloid (center), and special formulation of 99mTc-HSA microcolloid, not available commercially (151) (right). Even on early imaging, radiocolloids with small and intermediate particle size visualize several nodes in addition to sentinel node, whereas only sentinel node is visualized by radiocolloid with relatively large particles.

View larger version (35K): [in a new window]   FIGURE 6. Scintigraph obtained in anterior view about 45–60 min after injecting 2 separate aliquots of 99mTc-HSA nanocolloid (about 7 MBq [200 µCi] each) intradermally and, 15 min later, intraparenchymally in right breast; contour of body in area under evaluation is identified with aid of radioactive point source. Intradermal injection ensures visualization of single sentinel lymph node between breast and axilla, whereas intraparenchymal injection visualizes lymphatic drainage toward internal mammary chain (at least 3 sequential lymph nodes).

View larger version (61K): [in a new window]   FIGURE 7. Representative scans illustrate variable patterns of lymphatic drainage that would not be discerned only by intraoperative -probe counting. Imaging times were between 30 and 60 min after intradermal injection of 99mTc-HSA nanocolloid. (A) Right anterior oblique (RAO) view shows single lymphatic vessel leading to single sentinel lymph node, with serial visualization of subsequent-tier nodes. (B) Left anterior oblique (LAO) view shows 2 separate lymphatics leading, through widely diverging pathways, to 2 separate but adjacent sentinel nodes (with serial visualization of subsequent-tier nodes). (C) LAO view shows 3 separate lymphatics leading, through widely diverging pathways, to 2 separate but very close sentinel nodes (2 of vessels, originating at opposite poles of injection site, merge in single channel before crossing path of third vessel). (D) RAO view shows multiple lymphatics leading from site of injection in outer upper quadrant to at least 3 separate sentinel nodes (with serial visualization of subsequent-tier nodes).