Sentinel node biopsy for breast cancer: does the number of sentinel nodes removed have an impact on the accuracy of finding a positive node?

Ultrabright AIEdots with tunable narrow emission for multiplexed fluorescence imaging

AIEgen doped fluorescent nanodots (AIEdots) have attracted lots of attention, due to their superior characteristics as fluorescent probes, such as excellent photostability, large Stokes shift, high brightness and tunable emission. Unfortunately, most of the currently available AIEdots exhibit broad emission bandwidth, which limits their applications in multiplexed fluorescence imaging and detection. In this work, the strategy of designing and fabricating narrow emissive AIEdots (NE-AIEdots) with tunable wavelengths was presented by constructing a light-harvesting system with high energy transfer efficiency. Efficient intra-particle energy transfer from highly doped AIEgens, serving as the light-harvesting antenna, to the lightly doped narrow emissive fluorophore, resulted in high brightness and narrow emission. The emission band of NE-AIEdots with the full-width-at-half-maximum varied from 18 to 36 nm was 3-6.3 times narrower than that of traditional AIEdots. The single-particle brightness of NE-AIEdots was over 5-times that of commercial quantum dots under the same excitation and collection conditions. Taking advantage of the superior performance of these NE-AIEdots, multiplexed fluorescence imaging of lymph nodes in living mice was realized, which supported the future applications of NE-AIEdots for in vivo multiplexed labeling and clinical surgery.

Desirable Properties of Radiopharmaceuticals for Sentinel Node Mapping in Patients With Breast Cancer Given the Paradigm Shift in Patient Management

Over the past 2 decades, lymphoscintigraphy and sentinel node biopsy have become widely accepted and are used by surgeons to stage many solid cancers, especially breast cancer. However, despite growing experience, there are a number of unresolved issues. In addition, the impact of a new radiopharmaceutical remains to be determined. The present article addresses some of these issues (either unresolved, recurrent, or newly emerged), with a focus on the properties of radiopharmaceuticals used for sentinel node mapping in breast cancer.

Impact of Semiconducting Perylene Diimide Nanoparticle Size on Lymph Node Mapping and Cancer Imaging

Semiconducting molecules of perylene diimide (PDI) with strong light absorption properties in the near-infrared region and good biocompatibility have received increasing attention in the field of theranostics, especially as photoacoustic (PA) imaging agents. Herein, we report a series of [⁶⁴Cu]-labeled PDI nanoparticles (NPs) of different sizes (30, 60, 100, and 200 nm) as dual positron emission tomography (PET) and PA imaging probes and photothermal therapy agents. The precise size control of the PDI NPs can be achieved by adjusting the initial concentration of PDI molecules in the self-assembly process, and the photophysical property of different sized PDI NPs was studied in detail. Furthermore, we systematically investigated the size-dependent accumulation of the PDI NPs in the lymphatic system after local administration and in tumors after intravenous injection by PA and PET imaging. The results revealed that 100 nm is the best size for differentiating popliteal and sciatic LNs since the interval is around 60 min for the NPs to migrate from popliteal LNs to sciatic LNs, which is an ideal time window to facilitate surgical sentinel LN biopsy and pathological examination. Furthermore, different migration times of the different-sized PDI NPs will provide more choices for surgeons to map the specific tumor relevant LNs. PDI NP theranostics can also be applied to imaging-guided cancer therapy. The NPs with a size of 60 nm appear to be the best for tumor imaging and photothermal cancer therapy due to the maximum tumor accumulation efficiency. Thus, our study not only presents organic PDI NP theranostics but also introduces different-sized NPs for multiple bioapplications.

Do the ACOSOG Z0011 Criteria Affect the Number of Sentinel Lymph Nodes Removed?

INTRODUCTION

We sought to determine if adoption of the Z0011 criteria was associated with removal of more sentinel lymph nodes (SLNs).

METHODS

In a retrospective review of a prospective database of breast cancer patients treated at our institution from 2006 to 2013, we identified 5213 eligible patients who elected to undergo breast-conserving surgery; 2372 were treated pre-Z0011 and 2841 post-Z0011. Clinicopathologic factors were collected, and univariate and multivariate models were fit to identify variables associated with number of SLNs removed.

RESULTS

Median patient age, 60 years, did not differ between groups. Median tumor size was similar in both groups: 1.1 (0.05-5.0) cm in the pre-Z0011 group and 1.2 (0.1-5.2) cm in the post-Z0011 group. The mean number of SLNs excised in the pre-Z0011 patients was 2.8 compared with 2.9 in post-Z0011 patients (p = 0.01). Three or fewer lymph nodes were removed in 1771 (75 %) pre-Z0011 patients compared with 2006 (71 %) post-Z0011 patients (p = 0.01). Factors associated with the removal of more SLNs on multivariate analysis included adoption of ACOSOG Z0011 criteria (p = 0.03), young age (p ≤ 0.0001), and large tumor size (p = 0.0005). Axillary lymph node dissection (ALND) was performed in 379 (16 %) patients pre-Z0011 compared with 68 (2 %) node-positive post-Z0011 patients (p < 0.0001).

CONCLUSIONS

Since the adoption of Z0011 criteria, we found significantly fewer patients undergoing ALND for positive SLNs. We noted a significant, slight shift in the removal of ≥4 SLNs. The Z0011 criteria were not associated with a clinically significant increase in the number of SLNs removed.

Comparison of [(99m)Tc]tilmanocept and filtered [(99m)Tc]sulfur colloid for identification of SLNs in breast cancer patients

Background

The efficacy of sentinel lymph node (SLN) surgery requires targeted removal of first-draining nodes; however, frequently more nodes are removed than necessary. [^99mTc]tilmanocept (TcTM) is a molecular-targeted radiopharmaceutical specifically designed for SLN mapping. We evaluated technical outcomes of SLN biopsy in breast cancer patients mapped with TcTM + vital blue dye (VBD) versus filtered [^99mTc]sulfur colloid (fTcSC) + VBD.

Methods

There were 84 versus 115 patients in the TcTM versus fTcSC cohorts, respectively. Main measures were the number of SLNs removed per patient and factors influencing number of nodes removed. We also evaluated whether the radiotracer injected affected the proportion of positive nodes removed in node-positive patients.

Results

Fewer nodes were removed among patients mapped with TcTM compared to fTcSC (mean TcTM: 1.85 vs. fTcSC: 3.24, p < 0.001). Logistic regression analysis adjusted for tumor characteristics showed that injection of fTcSC (p < 0.001) independently predicted removal of greater than 3 nodes. A similar proportion of patients was identified as node-positive, whether mapped with TcTM or with fTcSC (TcTM: 24 % vs. fTcSC: 17 %, p = 0.3); however, TcTM detected a greater proportion of positive nodes among node-positive patients compared with fTcSC (0.73 vs. 0.43, p = 0.001).

Conclusions

Patients undergoing SLN biopsy with TcTM required fewer SLNs to identify the same rate of node-positive patients compared with fTcSC in breast cancer patients with similar risk of axillary metastatic disease. These data suggest that a molecularly targeted mechanism of SLN identification may reduce the total number of nodes necessary for accurate axillary staging.

Sentinel nodes identified by computed tomography-lymphography accurately stage the axilla in patients with breast cancer

BACKGROUND

Sentinel node biopsy often results in the identification and removal of multiple nodes as sentinel nodes, although most of these nodes could be non-sentinel nodes. This study investigated whether computed tomography-lymphography (CT-LG) can distinguish sentinel nodes from non-sentinel nodes and whether sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer.

METHODS

This study included 184 patients with breast cancer and clinically negative nodes. Contrast agent was injected interstitially. The location of sentinel nodes was marked on the skin surface using a CT laser light navigator system. Lymph nodes located just under the marks were first removed as sentinel nodes. Then, all dyed nodes or all hot nodes were removed.

RESULTS

The mean number of sentinel nodes identified by CT-LG was significantly lower than that of dyed and/or hot nodes removed (1.1 vs 1.8, p <0.0001). Twenty-three (12.5%) patients had ≥2 sentinel nodes identified by CT-LG removed, whereas 94 (51.1%) of patients had ≥2 dyed and/or hot nodes removed (p <0.0001). Pathological evaluation demonstrated that 47 (25.5%) of 184 patients had metastasis to at least one node. All 47 patients demonstrated metastases to at least one of the sentinel nodes identified by CT-LG.

CONCLUSIONS

CT-LG can distinguish sentinel nodes from non-sentinel nodes, and sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Successful identification of sentinel nodes using CT-LG may facilitate image-based diagnosis of metastasis, possibly leading to the omission of sentinel node biopsy.

[Metastases in patients with breast cancer despite of negative sentinel lymph node. Has the concept to be changed?]

The sentinel lymph node (SLN) is of considerable prognostic relevance, because extended lymph node dissection may not be performed in patients presenting with histologically negative SLN. The aim of this study was to prove the prognostic value of the SLN-concept in these patients in long term follow-up.

PATIENTS, METHODS

The clinical follow-up of 202 women with histologically proven breast cancer and metastatically uninvolved (negative) SLN, as determined using Tc-99m-nanocolloid, was observed for a mean period of 43.4 months. Histological examination included standard methods (HE-Test) and special histochemical techniques (antibodies against cytokeratin). All patients underwent clinical examinations and mamography according a standardised schema; other procedures like ultrasound examination, routine blood tests, and chest X-ray scans were performed in patients considered doubtful after clinical examination or mamography.

RESULTS

Despite of negative SLN-findings in 14/202 patients (6.9%) metastases were found after a mean time period of 35.9 months. 4 patients showed local re-lapses, 3 patients presented with regional lymph node recurrences in the previously mapped (negative) SLN-basin, and 7 Patients developed distant metastases outside the primary lymphatic basin.

CONCLUSION

In patients negative on SLN-biopsy the axillary lymph-node-recurrence-rate was low; in 3/202 patients (1.5%) a progression in the SLN-basin could be assessed, being real concept failures. Our results underline that there is no evidence to question this concept in patients presented with clinically metastatically uninvolved early stage of breast cancer.

Lymphatic mapping with fluorescence navigation using indocyanine green and axillary surgery in patients with primary breast cancer

The indocyanine green fluorescence (ICGf) navigation method provides real-time lymphatic mapping and sentinel lymph node (SLN) visualization, which enables the removal of SLNs and their associated lymphatic networks. In this study, we investigated the features of the drainage pathways detected with the ICGf navigation system and the order of metastasis in axillary nodes. From April 2008 to February 2010, 145 patients with clinically node-negative breast cancer underwent SLN surgery with ICGf navigation. The video-recorded data from 79 patients were used for lymphatic mapping analysis. We analyzed 145 patients with clinically node-negative breast cancer who underwent SLN surgery with the ICGf navigation system. Fluorescence-positive SLNs were identified in 144 (99%) of 145 patients. Both single and multiple routes to the axilla were identified in 47% of cases using video-recorded lymphatic mapping data. An internal mammary route was detected in 6% of the cases. Skip metastasis to the second or third SLNs was observed in 6 of the 28 node-positive patients. We also examined the strategy of axillary surgery using the ICGf navigation system. We found that, based on the features of nodal involvement, 4-node resection could provide precise information on the nodal status. The ICGf navigation system may provide a different lymphatic mapping result than computed tomography lymphography in clinically node-negative breast cancer patients. Furthermore, it enables the identification of lymph nodes that do not accumulate indocyanine green or dye adjacent to the SLNs in the sequence of drainage. Knowledge of the order of nodal metastasis as revealed by the ICGf system may help to personalize the surgical treatment of axilla in SLN-positive cases, although additional studies are required.

Assessing second echelon lymph nodes during sentinel lymph node biopsy: can we have more accurate axillary treatment for breast cancer patients?

Sentinel lymph node biopsy (SLNB) is the standard treatment for breast cancer patients with clinically negative axilla. For patients with positive sentinel lymph nodes, axillary lymph node dissection (ALND) was required. However, approximately a half of the SLNs-positive patients were found to have clear axillary lymph nodes after ALND, indicating that they had received unnecessary ALND without therapeutic benefit. Therefore, we propose a hypothesis for solution of this clinical problem. We defined the second echelon lymph nodes (SELNs) as those nodes receiving lymphatic drainage directly from the SLNs. For patients with positive-SLNs, SELNs can be biopsy and assessed. If SELNs are negative, no more ALND was needed in these patients even if their SLNs are positive. If our hypothesis were confirmed to be true, we can tailored our axillary treatment to more breast cancer patients, avoiding unnecessary ALND and its complications.

[The potential role of SPECT/CT in the preoperative detection of sentinel lymph nodes in breast cancer]

Regional lymph node status is the most important prognostic factor in breast cancer. Sentinel lymph node biopsy is the standard method of axillary staging in early breast cancer patients with clinically negative nodes. Preoperative lymphoscintigraphy might support refining biopsy findings by determining the number and location of sentinel lymph nodes. In aged or overweight patients, in the presence of atypical or extra-axillary lymphatic drainage, non-visualized lymph nodes, or sentinel lymph nodes close to the isotope injection site, detection could be aided by a new, hybrid imaging tool: the single-photon emission computed tomography combined with computed tomography (3D SPECT/CT). For the first time in Hungarian language, authors overview the literature: all 14 English-language articles on the implementation of 3D SPECT/CT in sentinel lymph node detection in breast cancer are included. It is concluded that 3D SPECT/CT increases the success rate and quality of preoperative sentinel node identification, and is capable of providing a more accurate staging of breast cancer patients in routine clinical practice.

SPECT/CT for preoperative sentinel node localization

The value of SPECT/CT for detection and localization of sentinel nodes is reviewed. SPECT/CT depicts extra sentinel nodes and identifies non-nodal tracer accumulation. SPECT/CT is indicated in patients with complex lymphatic drainage as often present in patients with head, neck and scapular melanoma, breast cancer patients with extra-axillary sentinel nodes and patients with tumors draining to pelvic nodes. SPECT/CT also clarifies the drainage pattern of inconclusive conventional images (non-visualization or unclear location of the nodes).

First Three Sentinel Lymph Nodes Accurately Stage the Axilla in Breast Cancer

Sentinel lymph node (SLN) biopsy is the preferred method of assessing lymph nodes in breast cancer. Recent literature suggests increasing morbidity with increased number of SLN removed. However, controversy exists regarding the number of SLN that should be removed. A retrospective review of patients undergoing SLN biopsy for breast cancer from 2003 to 2005 was performed. Data analyzed included the number of SLNs, nodes per specimen, and pathology. The order of SLN removal was documented and the first positive lymph node noted. Three hundred fifty-three patients underwent successful SLN biopsy. On average, only one surgical SLN was identified. However, the average number of pathologically identified SLN was 1.3. Nodal disease was identified in 79 patients (22.4%). The first SLN was positive in 70 of those patients (88.6%). Six additional patients were diagnosed by the second SLN (76 of 79 [96.2%]), and all 79 patients were identified within the first three nodes. All patients with nodal disease were identified within three SLNs. These data support the concept that surgeons do not need to remove all identifiable sentinel nodes. Moreover, surgeons could consider limiting the number of excised SLNs to three.

Optimal number of radioactive sentinel lymph nodes to remove for accurate axillary staging of breast cancer

BACKGROUND

Although sentinel lymph node (SLN) biopsy is the standard technique for staging the axilla of clinically node-negative breast cancer, the optimal number of radioactive SLNs to remove to ensure accuracy and minimize morbidity is still actively debated. The purpose of this study was to determine the minimum number of SLNs to excise to ensure accurate axillary staging of SLN-positive patients.

METHODS

A total of 126 patients with invasive breast cancer underwent SLN biopsy by periareolar injection of radiolabeled technetium sulfur colloid on the day of surgery. The sequence in which SLNs were removed and the corresponding ex vivo radioactive counts were recorded. SLNs were removed until radioactive counts in the axilla were less than 10% of the ex vivo counts of the hottest SLN.

RESULTS

A radioactive SLN was identified in every patient. The mean number of SLNs identified was 2.86 (range, 1-8). Clinicopathologic features associated with a positive SLN included a palpable tumor (P = .0035), increasing tumor size (P = .0039), increasing histologic grade (P = .0234), and angiolymphatic invasion (P < .001). The highest radioactive counts were found in the first node in 100 patients (79.4%), the second node in 15 (11.9%), and the third or later node in 11 patients (8.7%). Among the 38 patients with a positive SLN (30.2%), the hottest node was the first positive SLN in 27 patients (71.1%). The first positive SLN was the first node removed in 31 patients (81.6%) and after the second node in 37 patients (97.4%); it was removed in all patients by the third SLN.

CONCLUSION

These data support the trend of limiting SLN biopsy to 3 lymph nodes. Removing all SLNs with radioactive counts greater than 10% of the ex vivo counts of the hottest SLN did not increase accuracy.

Factors influencing the number of sentinel lymph nodes identified in patients with breast cancer

BACKGROUND

Although the sentinel lymph node (SLN) is defined as the first node draining a tumor, multiple nodes are often identified. Few SLNs are required for adequate staging; removal of more may be unnecessary. The objective of this study was to determine factors influencing the number of SLN identified.

METHODS

The University of Louisville Breast Sentinel Lymph Node Study was used to determine correlates of identifying greater than 4 SLNs by using univariate and multivariate analyses.

RESULTS

An SLN was identified in 3,882 of 4,131 patients (94%). The median number of SLN identified was 2 (range 1-18); 90% had < or = 4 SLNs identified. Palpable tumors, surgeon inexperience, and dermal injection were associated with greater than 4 SLNs identified. All 3 of these factors remained significant on multivariate analysis.

CONCLUSIONS

Palpable tumors often have greater than 4 SLNs identified, and the use of intradermal injection increases this probability.

Radio-guided sentinel lymph node biopsy using periareolar injection technique for patients with early breast cancer

BACKGROUND/PURPOSE

Sentinel lymph node (LN) biopsy has been widely adopted in the axillary staging of clinical node-negative breast cancer patients. This study aimed to evaluate the accuracy of radio-guided sentinel LN (SLN) biopsy (SLNB) using the periareolar injection technique for predicting the histopathologic status of axillary LNs in early breast cancer patients.

METHODS

Between November 2003 and November 2004 in the National Taiwan University Hospital, radio-guided SLNB using the periareolar injection technique was consecutively performed in 213 female patients with early breast cancer (stage T1 and T2) but without clinically palpable axillary LN and previous chemotherapy. Two mCi of filtered (0.22 microm) (99m)Tc-sulfur colloid were injected in the afternoon 1 day before surgery (2-day protocol) or 1 mCi of the same radiopharmaceutical was injected on the morning of the surgery (1-day protocol). During surgery, a handheld gamma probe was used to identify the LNs with radioactivity in the axilla. A node was deemed a SLN if its radioactivity was >10% of the hottest node. All the SLNs identified were removed for histology.

RESULTS

Radioactive SLN was identified at surgery in 207 patients. The SLN identification rate was 97.2% (207/213). Of these 207 patients, 163 patients had received both SLNB and axillary LN dissection. Among these 163 patients, 77 patients had LN metastases and four had negative SLN but positive non-SLN. The false-negative rate of SLNB for the detection of axillary LN metastases was 5.2% (4/77). There were no statistical differences between false-negative and SLN positive groups for all factors.

CONCLUSION

Our study suggests that SLNB with periareolar injection of radiocolloid provides valuable information on the axillary nodal status in patients with early breast cancer.

Re-emphasizing the concept of adequacy of intraoperative assessment of the axillary sentinel lymph nodes for identifying nodal positivity during breast cancer surgery

Background

Although sentinel lymph node (SLN) biopsy is a standard of care for the evaluation of the axillary lymph nodes during breast cancer surgery, a substantial degree of variation exists among individual surgeons as to what represents an adequate assessment. The aim of the current study was to assess when metastatic disease was first identified within consecutively harvested SLN candidates for invasive breast cancers demonstrating a positive SLN.

Methods

We retrospectively analyzed a series of 400 breast cancers from a recently published prospective randomized clinical trial. A combined radiocolloid and blue dye technique was used. All potential SLN candidates, containing counts of at least 10% of the hottest SLN and/or containing blue dye, were harvested and were consecutively numbered in the order of the decreasing level of counts (with the hottest SLN representing SLN #1).

Results

Among 371 invasive breast cancers, a SLN was identified within 353 cases (95%). Mean number of SLNs identified was 2.5 (range, 1 to 9), with a single SLN identified in 104 (29%) cases, two identified in 110 (31%), three identified in 73 (21%), four identified in 35 (10%), five identified in 16 (5%), and six or more identified in 15 (4%). A positive SLN was found in 104 (29%) cases. SLN #1 was the first positive SLN in 86 (83%). SLN #2 was the first positive SLN in 15 (14%). SLN #3, SLN #4, and SLN #5 were the first positive SLN in one case (1%) each. A positive SLN was found in 18% (19/104) of cases when a single SLN was identified, as compared to in 34% (85/249) when two or more SLNs were identified (P = 0.003).

Conclusion

The accurate and optimal assessment of the axilla during breast cancer surgery requires persistence and diligence for attempting to identify all potential SLN candidates in order to avoid failing to recognize a positive SLN. The scenario in which only a single negative SLN candidate is intraoperatively identified is one that should raise some concern to the operating surgeon.

Sentinel lymph node biopsy for breast cancer: How many nodes are enough?

INTRODUCTION

Sentinel lymph node (SLN) biopsy using blue dye and radioisotope often results in the removal of multiple SLNs. We sought to determine whether there is a point where the surgeon can terminate the procedure without sacrificing accuracy.

METHODS

One thousand one hundred ninety-seven patients from University of Michigan and the Mayo Clinic undergoing SLN biopsy formed the study population. Surgeons removed all SLNs until counts within the axilla were less than 10% of the highest node ex vivo and recorded the order in which they were removed.

RESULTS

The mean number of SLNs removed per patient was 2.5 (range 1-9). Approximately 42% of patients had three or more lymph nodes removed, while 19% had four or more lymph nodes removed. Eighteen percent of patients (132/725) at University of Michigan and 22% (103/472) at Mayo Clinic had a positive SLN. Ninety-eight percent (231/235) of patients with lymph node metastases were identified by the 3rd SLN while 100% were identified by the 4th SLN.

CONCLUSION

Among patients undergoing SLN biopsy for breast cancer, the only positive SLN is rarely identified in the 4th or higher node. Terminating the procedure at the 4th node may lower the cost of the procedure and reduce morbidity.

Maladie micrométastatique et maladie résiduelle axillaire. Exemple du cancer du sein

The knowledge of the axillary involvement is a major prognosis factor for breast cancer and an important parameter for treatment decision. Nevertheless, two recent current medical situations have occurred in breast cancer, changing our management. First, with the development of mass screening and sentinel lymph nodes biopsies, we have to take treatment decisions based upon minimal lymph node involvement, with a clinical significance still poorly understood. Second, for the large tumors, potentially with lymph node involvement, we have to deal with tumor and lymph node under staging, after induction chemotherapy. We have to learn how to evaluate accurately those new parameters to treat the best way our patients.

Radiolocalized Sentinel Lymph Node Biopsy in Squamous Cell Carcinoma of the Oral Cavity and Analysis of Various Parameters

BACKGROUND

Sentinel lymph node (SLN) biopsy seems to be a method that solves the problem of neck management with oral squamous cell carcinoma. Using blue dye methods for detection of neck SLNs from the surface of the operative field seems difficult; therefore, we used radiolocalization alone to detect and extract sentinel nodes. Aside from the various histological and clinical parameters examined in this procedure, we also determined whether they had any clinical significance in relation to the detection of SLNs during the operation.

METHODS

Enrolled subjects had preoperative clinical N0 stage squamous cell carcinoma of the oral cavity and had received an unfiltered (99m)Tc sulfur colloid peritumoral injection. Localization of the SLNs was performed by using lymphoscintigraphy and a handheld gamma probe.

RESULTS

In total, 28 oral squamous cell carcinoma patients were included in this prospective study. Sixty-four SLNs in 27 patients were identified by this method. The identification rate was 96.4%. No false-negative predictions of SLN were noted among any of the patients studied. The numbers of the SLNs found during the operation were larger in patients with positive findings than those with negative findings (P < .05 by the Mann-Whitney U-test).

CONCLUSIONS

SLN radiolocalization provided an acceptable identification rate. The cases of positive findings for metastasis seemed to statistically have more SLNs than did those with negative findings, but more evidence is needed to prove this point. Therefore, SLN biopsies for extracting all possible high-risk nodes may be conducive for oral squamous cell carcinoma surgery.

Lymphoscintigraphy and triangulated body marking for morbidity reduction during sentinel node biopsy in breast cancer

Current trends in patient care include the desire for minimizing invasiveness of procedures and interventions. This aim is reflected in the increasing utilization of sentinel lymph node biopsy, which results in a lower level of morbidity in breast cancer staging, in comparison to extensive conventional axillary dissection. Optimized lymphoscintigraphy with triangulated body marking is a clinical option that can further reduce morbidity, more than when a hand held gamma probe alone is utilized. Unfortunately it is often either overlooked or not fully understood, and thus not utilized. This results in the unnecessary loss of an opportunity to further reduce morbidity.

Optimized lymphoscintigraphy and triangulated body marking provides a detailed 3 dimensional map of the number and location of the sentinel nodes, available before the first incision is made. The number, location, relevance based on time/sequence of appearance of the nodes, all can influence 1) where the incision is made, 2) how extensive the dissection is, and 3) how many nodes are removed. In addition, complex patterns can arise from injections. These include prominent lymphatic channels, pseudo-sentinel nodes, echelon and reverse echelon nodes and even contamination, which are much more difficult to access with the probe only. With the detailed information provided by optimized lymphoscintigraphy and triangulated body marking, the surgeon can approach the axilla in a more enlightened fashion, in contrast to when the less informed probe only method is used. This allows for better planning, resulting in the best cosmetic effect and less trauma to the tissues, further reducing morbidity while maintaining adequate sampling of the sentinel node(s).

Ratio of Positive to Total Number of Sentinel Nodes Predicts Nonsentinel Node Status in Breast Cancer Patients

Selective sentinel lymphadenectomy (SSL) has replaced axillary lymph node dissection (ALND) for many patients with early breast cancer and negative sentinel lymph nodes (SLNs). Yet many patients with a positive SLN are undergoing unnecessary ALND, as no further disease is found in the axilla. The aim of our study was to determine factors associated with additional positive lymph nodes in the axilla in patients who have a positive SLN. This was a retrospective study of patients undergoing SSL with ALND as part of their treatment for breast cancer at a single institution from November 1997 to August 2003. Only patients with one or more positive SLNs were selected for this study. There were 86 patients who fit our study criteria. Of these, 38% had further positive lymph nodes upon ALND. More than one positive SLN and a ratio of positive SLNs to total SLNs of greater than 0.5 were found to be predictors for additional axillary nodal involvement in both univariate and multivariate analyses. The number of positive SLNs and the ratio of positive SLNs to total SLNs is an indication of total tumor burden in the sentinel nodes and may be a reflection of the propensity of the tumor for further lymphatic invasion in the axillary basin.

Clinical breast lymphoscintigraphy: optimal techniques for performing studies, image atlas, and analysis of images

Breast lymphoscintigraphy is increasingly performed before surgery to delineate the drainage to the sentinel node (SN) in the axilla. On the basis of the histologic status of harvested SNs, the disease status of the entire axilla can be predicted. This prediction allows a more limited dissection to be performed while maintaining staging accuracy comparable with that of classic axillary lymph node dissection. Lymphoscintigraphy assists surgeons in harvesting the SN during gamma probe-assisted axillary biopsy or dissection and provides a wide field of view survey, among other benefits. When certain injection protocols are used, lymphoscintigraphy can be performed in the afternoon before surgery the next morning, thus minimizing disruptions of tight surgical schedules. Image acquisition can be optimized and SN activity can be maximized by means of such factors as parameters for preparation of the radiotracer, injection techniques, energy settings for the gamma camera, breast displacement maneuvers, and techniques for marking and outlining the patient's body. The ultimate goals are to delineate the true SN, maximize activity in the node for facilitated removal (even at next-day surgery), and deliver the information to the surgeon without delaying the surgical schedule.

Criteria for establishing the adequacy of a sentinel lymphadenectomy

BACKGROUND

Criteria are needed that could be used to terminate a sentinel lymphadenectomy for breast cancer prior to removing every sentinel lymph node, without increasing false negative rates.

METHODS

Quantitative information on the radioactivity and color of sentinel lymph nodes removed from 541 breast cancer patients was correlated with pathologic information to determine when a sentinel lymphadenectomy could be terminated based on characteristics of the initially removed nodes.

RESULTS

Tumor was found in the first two sentinel lymph nodes removed in 127 of 129 node-positive patients. In 65% of patients who were able to be evaluated, the most radioactive lymph node was a positive lymph node. When any axillary lymph node was blue, then the first tumor-containing sentinel lymph node was also blue.

CONCLUSIONS

Removal of the most radioactive lymph node does not insure accurate assessment of the axilla. Removal of two sentinel lymph nodes accurately staged 98.4% of node-positive patients and 99.6% of the entire study population.

The sensitivity of axillary staging when using sentinel node biopsy in breast cancer

AIMS

We aimed to study factors, which enhance the sensitivity of sentinel node biopsy.

METHODS

Three hundred and sixty-three clinically node negative breast cancer patients with successful sentinel node biopsy were studied. All focally radioactive and/or blue nodes in the axilla were harvested. All palpably suspicious lymph nodes were also removed for a similar histological evaluation.

RESULTS

Sentinel node metastases were found in 129 patients. The metastasis was detected in the three first retrieved sentinel nodes in 126 cases and in the fourth or fifth node in three cases. The 'hottest' sentinel node was not the involved one in 18 cases. Five patients with tumour negative sentinel nodes had metastases in other palpably suspicious nodes.

CONCLUSIONS

Harvesting all focally radioactive and/or blue nodes and other palpably suspicious nodes minimises the false negative rate in sentinel node biopsy. Removal of more than five nodes does not significantly improve the sensitivity of axillary staging.

Removal of two sentinel nodes accurately stages the axilla in breast cancer

Background

Assessment of lymph node status in breast cancer is still necessary for staging. Sentinel lymph node biopsy (SNB) may provide accurate staging with less morbidity than axillary clearance. The aim of this study was to assess the effect of the number of sentinel nodes removed on the false-negative rate.

Methods

Data were collected prospectively from 395 women undergoing SNB for breast cancer, between June 1995 and December 2001. All nodes that were hot and/or blue were removed and analysed.

Results

During this interval 136 patients who had SNB were lymph node positive. The median number of sentinel nodes removed was two (range one to five). The overall false-negative rate of SNB in these women was 7·1 per cent. If only one sentinel node had been removed, the false-negative rate would have been 16·5 per cent. The removal of more than two nodes had no effect on axillary staging in all but two women.

Conclusion

In early breast cancer, when there were multiple sentinel nodes, removal of two sentinel nodes significantly reduced the false-negative rate compared with removal of one node. Removing more than two sentinel nodes did not significantly reduce the false-negative rate further.

Minimally invasive lymphatic mapping using fluorescently labeled vitamin B12

BACKGROUND

We examined the usefulness of a new agent in the mapping and dissection of inguinal lymph nodes in the pig. Cy5-cobalamin bioconjugate is blue under visible light and fluoresces brilliant red with laser stimulation. The wavelength of the emitted red light is sufficiently long that it is visible through blood, subcutaneous fat, and fascia. Currently available surgical techniques of minimally invasive dissection are well suited for using fluorescent detection in a dark operating field with minimal modification of an existing Hopkins surgical telescope.

MATERIALS AND METHODS

We tested this concept in the live post-adolescent, female, nonlactating pig (30 kg). We insufflated the subcutaneous tissue over the groin and inserted three ports (1 x 10 mm and 2 x 5 mm) for dissection. We injected the Cy5-cobalamin bioconjugate in a dermal location on the hind limb. A HeNe laser stimulated the CobalaFluor in the lymphatics and the emitted fluorescence passed through a holographic notch filter to a three-chip camera.

RESULTS

Under white light, the lymphatic trunks and the sentinel node were visualized within minutes of injection. Both the lymphatic trunks and the node fluoresced bright red under stimulation with red laser light.

CONCLUSIONS

These preliminary studies establish the potential usefulness of this new agent in lymphatic mapping. This novel technology might be useful in visualizing cancers that spread to regional lymph nodes. This technique has the potential to map the lymphatic drainage and to identify the presence of malignant cells in that drainage with currently available minimally invasive technology.