The role of sentinel lymph node biopsy in breast cancer

Comparison of the indocyanine green dye method versus the combined method of indigo carmine blue dye with indocyanine green fluorescence imaging for sentinel lymph node biopsy in breast conservative therapy for stage ≤IIA breast cancer

BACKGROUND

Fluorescence imaging (FI) is one of the methods to identify sentinel lymph nodes (SLNs). However, the procedure is technically complicated and requires procedural skills, as SLN biopsy must be conducted in dim light conditions. As an improved version of this method, we introduced a combined method (Combined mixed dye and fluorescence; CMF) consisting of indigo carmine blue dye and FI. The direct visualization of SLNs under shadowless surgical light conditions is facilitated by the addition of the blue dye. We compared the SLN detection rates of CMF with that of the indocyanine green (ICG) dye method (ICG-D).

METHODS

A total of 202 patients with stage ≤IIA breast cancer who underwent breast conservative therapy with separate incision from January 2004 to February 2017 were reviewed. Details of the two methods are as follows: (1) ICG-D: 10 mg of ICG was used and the green-stained SLNs were resected via a 3-4 cm axillary incision; (2) CMF: A combination of 5 mg of ICG and 4-8 mg of indigo carmine was used. After a 1.5-2 cm incision was made near the point of disappearance of the fluorescence using Photodynamic Eye (PDE), the blue-stained SLNs were resected under shadowless surgical light conditions.

RESULTS

There were 92 ICG-D and 110 CMF cases. CMF resulted in a significantly higher SLN detection rate than ICG-D (96.4% vs. 83.7%; p = 0.003). This difference was particularly notable in those aged ≥60 years (98.3% vs. 74.3%) and individuals with body mass index (BMI) ≥25 kg/m² (90.3% vs. 58.3%).

CONCLUSION

CMF is an effective method to identify SLNs which is safe and efficient. CMF achieves a high SLN identification rate and most of this procedure is feasible under shadowless surgical light conditions. CMF can reliably perform SLN biopsy even in those aged ≥60 years and individuals with BMI ≥ 25 kg/m².

Evans Blue Dye: A Revisit of Its Applications in Biomedicine

Evans blue (EB) dye has owned a long history as a biological dye and diagnostic agent since its first staining application by Herbert McLean Evans in 1914. Due to its high water solubility and slow excretion, as well as its tight binding to serum albumin, EB has been widely used in biomedicine, including its use in estimating blood volume and vascular permeability, detecting lymph nodes, and localizing the tumor lesions. Recently, a series of EB derivatives have been labeled with PET isotopes and can be used as theranostics with a broad potential due to their improved half-life in the blood and reduced release. Some of EB derivatives have even been used in translational applications in clinics. In addition, a novel necrosis-avid feature of EB has recently been reported in some preclinical animal studies. Given all these interesting and important advances in EB study, a comprehensive revisiting of EB has been made in its biomedical applications in the review.

State of the Art of Sentinel Node Biopsy in Oncology

Sentinel node biopsy has become a standard diagnostic procedure to assess lymph node status of various tumors. The combination of blue dye and a radioactive tracer offers the best chances of identifying the sentinel lymph node. Most progress in the technique of the sentinel node procedure has been made in melanoma and breast cancer. In melanoma, sentinel node biopsy has been introduced as a fundamental procedure for staging. Information on the lymphatic drainage from a melanoma can have a direct impact on the surgery. More recently, the technique has been successfully introduced in the management of breast cancer, in which a large number of unnecessary axillary dissections could be avoided. However, there are many other potential fields of application of the sentinel node biopsy (e.g. endometrial, vulvar, head and neck cancers) that are worthy of investigation. In any case, multicenter trials are required to standardize the procedures, taking into account several variables such as particle size and mode of delivery of the radiotracer, amount of radioactivity administered, number and location of injections, and choice of the hand-held probe. We briefly describe the technical and historical aspects of the sentinel node biopsy and summarize the main clinical trials proposed and/or performed in the field.

99mTc-labeled sodium phytate and stannous chloride injection accurately detects sentinel lymph node in axillary of early stage breast cancer: a randomized, controlled study

Aim

The aim of this study was to assess the sentinel lymph node (SLN) detection rate and accuracy of ^99mTc-labeled sodium phytate and stannous chloride (^99mTc-PHY) injection versus ^99mTc-labeled sulfur colloid (^99mTc-SC) injection in sentinel lymph node biopsy (SLNB) in patients with early stage breast cancer.

Methods

A total of 146 consecutive female patients with early stage breast cancer were recruited in this open-labeled, randomized, controlled study. SLNB was conducted on all patients, and ^99mTc-PHY or ^99mTc-SC was used as the radioactive agent (RA). Axillary lymph node dissections were performed in all patients post SLN dissections.

Results

The detection rate of ^99mTc-PHY group was higher compared with that of ^99mTc-SC group (p=0.023), but no difference in the detection rate by dye alone (p=0.190) or by RAs alone (p=0.615) was found between the two groups, and the number of identified SLNs (p=0.100), number of identified SLNs by dye alone (p=0.161), and number of identified SLNs by RA alone (p=0.242) were similar between the two groups. In addition, the sensitivity, specificity, false-negative rate, false-positive rate, and accuracy rate of SLNB showed no difference between ^99mTc-PHY and ^99mTc-SC groups (sensitivity: p=0.645; specificity: p=0.511; false-negative rate: p=0.645; false-positive rate: p=0.511; accuracy rate: p=0.464).

Conclusion

Our study revealed that ^99mTc-PHY was qualified to be a convincing radiopharmaceutical in SLNB.

Sentinel lymph node biopsy and aberrant lymphatic drainage in recurrent breast cancer: Findings likely to change treatment decisions

BACKGROUND AND OBJECTIVES

It is not clear whether sentinel lymph node biopsy (SLNB) can be applied to patients with a second breast cancer or recurrence occurring at previously treated breast. The purpose of this study was to assess the feasibility of SLNB procedure in patients with recurrent breast cancer.

METHODS

Patients with non-metastatic recurrent N0 breast cancer at ipsilateral breast were included. Patients were grouped according to their initial breast, axilla, and overall surgery. Presence of drainage and its pattern as well as SLNB success rate and overall axillary involvement rates were assessed. Findings were compared.

RESULTS

Out of 75 patients, mean age was 52.5 years and disease-free interval was 82 (9-312) months. Lymphatic drainage was successful in 42 (56%) patients. Drainage positivity was more frequent in patients who were previously treated with SLNB (82.6%) than in patients who underwent axillary lymph node dissection (ALND) (44.2%; P = 0,002). Aberrant lymphatic drainage was detected in 64.3% of drainage positive patients. Success rate of reoperative SLNB was 92.9%. Adjuvant treatment plan was altered in 12 (16%) patients. In 15 patients, negative SLNB prevented axillary dissection.

CONCLUSIONS

Reoperative SLNB seems to be technically feasible in N0 recurrent breast cancer patients. It may further avoid unnecessary ALND and lead changes in adjuvant treatment plans. J. Surg. Oncol. 2016;114:796-802. © 2016 2016 Wiley Periodicals, Inc.

The combination of blue dye and radioisotope versus radioisotope alone during sentinel lymph node biopsy for breast cancer: a systematic review

Background

The combination of blue dye and radioisotope is most widely used to identify sentinel lymph nodes (SLNs) in patients with breast cancer. However, some individual studies suggested that dual tracers did not have an advantage over radioisotope alone in detecting SLNs. We performed a systematic review to investigate the added value of blue dye in addition to radioisotope.

Methods

We searched Pubmed and Embase. Prospective studies that compared the combination of radioisotope and blue dye with radioisotope alone were selected. The identification rate of SLNs and the false-negative rate were the main outcomes of interest. The odds ratios (ORs) and 95 % confidential intervals (CIs) were calculated by using random-effects model.

Results

Twenty-four studies were included. The combination of radioisotope and blue dye showed higher identification rate than radioisotope alone (OR = 2.03, 95 % CI 1.53–2.69, P < 0.05). However, no statistically significant difference was revealed for patients after neoadjuvant chemotherapy (OR = 1.64, 95 % CI 0.82–3.27, P > 0.05), or for studies with high proportion of patients with positive lymphoscintigraphy (OR = 1.41, 95 % CI 0.83–2.39, P > 0.05). Dual tracers did not significantly lower the false-negative rate compared with radioisotope alone (OR = 0.76, 95 % CI 0.44–1.29, P > 0.05).

Conclusions

Although the combination of blue dye and radioisotope outperformed radioisotope alone in SLN detection, the superiority for dual tracers may be limited for patients with positive lymphoscintigraphy or for those after neoadjuvant chemotherapy. Besides, the combined modality did not help lower the false-negative rate.

Sentinel lymph node biopsy in breast cancer: the role of micrometastasis

Intraoperative sentinel lymph node biopsy is widely used in patients with early-stage breast cancer for staging the axilla. The conventional analysis of the SLN has classically been performed by frozen section or touch imprint with a rapid H&E (hematoxylin and eosin) staining. Because of the risk of false-negative results, it has been replaced by the one-step acid amplification (OSNA) assay, a molecular diagnostic assay for the detection of cytokeratin 19 mRNA expression. Due to the controversial for the use of OSNA to evaluate the SLN because of its cost-effective and the lack of consensus to perform or avoid a lymphadenectomy when there is micrometastasis, we analyze 410 patients subjected to SLN biopsy in Hospital Puerta de Hierro, Madrid (Spain). Of the total of nodes, 223 (54.4 %) were processed throughout frozen-section examination and imprint cytology and 187 (45.6 %) throughout OSNA. The specificity of the frozen-section histological examination was of 100 %, with a sensitivity of 83.33 % (95 % CI 73.07-93.60). Of the 40 patients with definitive micrometastasis in the SLN, axillary dissection was performed in 90 % of the patients, with subsequent positive affectation in four of them (11.11 %). Based on our result and taking into account that 10 % of the lymphadenectomy performed after micrometastasis are positive, we do not believe that lymphadenectomy should be avoided after N(mi+) is detected in a SLN.

Sentinel lymph node biopsy in vulval cancer: systematic review and meta-analysis

BACKGROUND

The purpose of this study was to determine the accuracy of sentinel lymph node (SLN) biopsy with technetium 99 (99mTc) and/or blue dye-enhanced lymphoscintigraphy in vulval cancer.

METHODS

Sensitive searches of databases were performed upto October 2013. Studies with at least 75% of women with FIGO stage IB or II vulval cancer evaluating SLN biopsy with 99mTc, blue dye or both with reference standard of inguinofemoral lymphadenectomy (IFL) or clinical follow-up were included. Meta-analyses were performed using Meta-Disc version 1.4.

RESULTS

Of the 2950 references, 29 studies (1779 women) were included; most of them evaluated 99mTc combined with blue dye. Of these, 24 studies reported results for SLN followed by IFL, and 5 reported clinical follow-up only for SLN negatives. Pooling of all studies was inappropriate because of heterogeneity. Mean SLN detection rates were 94.0% for 99mTc, 68.7% for blue dye and 97.7% for both. SLN biopsy had pooled sensitivity of 95% (95% CI 92-98%) with negative predictive value (NPV) of 97.9% in studies using 99mTc/blue dye, ultrastaging and immunohistochemistry with IFL as reference. Pooled sensitivity for SLN with clinical follow-up for SLN-negatives was 91% (85-95%) with NPV 95.6%. Patients undergoing SLN biopsy experienced less morbidity than those undergoing IFL.

CONCLUSIONS

Sentinel lymph node biopsy using 99mTC, blue dye and ultrastaging with immunohistochemistry is highly accurate when restricted to carefully selected patients, within a rigorous protocol, with close follow-up and where sufficient numbers for learning curve optimisation exist. Patients must make an informed choice between the slightly higher groin recurrence rates of SLN biopsy vs the greater morbidity of IFL.

Sentinel lymph node biopsy for breast cancer: from investigational procedure to standard practice

Sentinel lymph node biopsy, popularized in melanoma, has revolutionized the management of breast cancer. While the morbidity associated with axillary node dissection was once thought to be a requisite risk in order to appropriately stage the axilla, large validation studies have demonstrated that sentinel lymph node biopsy is a minimally invasive technique that can accurately predict nodal status. This technique has become an accepted practice in many centers, but there remain many controversies surrounding the technique itself, the pathologic evaluation of the sentinel node and the optimal management of patients with minimal nodal disease. The historic roots of this technique are discussed, along with the controversial issues surrounding the technique and the clinical trials that are currently ongoing.

Prevalence and risk factors of intraoperative identification failure of sentinel lymph nodes in patients affected by breast cancer

INTRODUCTION

Sentinel lymph node biopsy (SLNB) has progressively replaced complete axillary lymph node dissection in the evaluation of breast cancer patients with clinically node-negative disease. Our study investigates the rate of and risk factors involved in sentinel node identification failure.

MATERIALS AND METHODS

We collected data on SLNBs performed during 2002-2010, focusing on tumor, patient, and breast characteristics, radioactivity parameters, and operators' experience. Data were analyzed by R (v2.14.2), considering significance at P values lower than 0.05.

RESULTS

Among 1050 women who underwent an SLNB, the rate of identification failure was 2% (23/1050), which, on bivariate analysis, was seen to be significantly influenced (P<0.05) by the preoperative and intraoperative low radiotracer uptake (axilla/lesion radiotracer uptake ratio<1%), low level of experience of the specialist in nuclear medicine, luminal A subtype, and radiotracer uptake localization in internal mammary lymph nodes. On multivariate analysis, significant risk factors for sentinel node identification failure were found to be: axilla/lesion radiotracer uptake ratio less than 1%, radiotracer uptake localization in internal mammary lymph nodes, and luminal A subtype. Considering only the preoperative variables in our multivariate analysis, axilla/lesion radiotracer uptake ratio less than 1%, negative lymph node scintiscan, and radiotracer uptake localization in internal mammary lymph nodes had an area under the curve (receiver operating characteristic curve) of 96% (95% confidence interval 92-100%). Further, we built a nomogram based on these simple parameters for counseling the patient about the probability of not finding the sentinel lymph node during the surgical procedure.

CONCLUSION

The relatively low prevalence of SLNB failure (2%) is indicative of the accuracy of the procedure when performed by experienced surgeons. The sentinel node identification failure in our population seemed to be related to biological tumor factors (luminal A subtype) and probably to physiological or pathological variations in the lymphatic drainage (axilla/lesion radiotracer uptake ratio<1% and radiotracer uptake localization in internal mammary lymph nodes).

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Trafficking of a dual-modality magnetic resonance and fluorescence imaging superparamagnetic iron oxide-based nanoprobe to lymph nodes

PURPOSE

This study aims to develop and characterize the trafficking of a dual-modal agent that identifies primary draining or sentinel lymph node (LN).

PROCEDURE

Herein, a dual-reporting silica-coated iron oxide nanoparticle (SCION) is developed. Nude mice were imaged by magnetic resonance (MR) and optical imaging and axillary LNs were harvested for histological analysis. Trafficking through lymphatics was observed with intravital and ex vivo confocal microscopy of popliteal LNs in B6-albino, CD11c-EYFP, and lys-EGFP transgenic mice.

RESULTS

In vivo, SCION allows visualization of LNs. The particle's size and surface functionality play a role in its passive migration from the intradermal injection site and its minimal uptake by CD11c+ dendritic cells and CD169+ and lys+ macrophages.

CONCLUSIONS

After injection, SCION passively migrates to LNs without macrophage uptake and then can be used to image LN(s) by MRI and fluorescence. Thus, SCION can potentially be developed for use in sentinel node resections or for intralymphatic drug delivery.

Local tissue reaction after injection of contrast media on gastric wall of mouse: experimental study for application of contrast media to computed tomography lymphography

Purpose

Computed tomography (CT) lymphography is a simple technique of sentinel node navigation but tissue reaction after injection of contrast media has not been reported yet.

Methods

Ninety mice used in this study were divided into three groups: lipiodol, iopamidol, and normal saline. The test compounds were given by submucosal injection to the gastric wall of anesthetized mice. The specimens were subjected to histopathological examination.

Results

The mean grades of acute inflammatory response after iopamidol and lipiodol injection were significantly higher than control group. However, there was no significant difference between iopamidol and lipiodol injection. The mean grade of chronic inflammatory response and fibrosis showed no differences between groups. The presence or absence of fibrinoid necrosis and mesothelial hyperplasia showed no statistical differences at each time point between groups. The foam cell, which is similar to human signet ring cell carcinoma, were not identified in normal saline and iopamidol group, but were detected by postoperative day 7 in lipiodol group.

Conclusion

We conclude that iopamidol and lipiodol when used as a contrast media of CT lymphography is an available material for preoperative sentinel node navigation surgery for gastric cancer with an acceptable incidence of pathological alterations in a mouse model. Our results are potentially useful to clinical (human) application.

A novel approach for sentinel lymph node identification using fluorescence imaging and image overlay navigation surgery in patients with breast cancer

BACKGROUND

We reported a novel technique of sentinel lymph node (SLN) identification using fluorescence imaging of indocyanine green injection. Furthermore, to obtain safe and accurate identification of SLN during surgery, we introduce the image overlay navigation surgery and evaluate its efficacy.

METHODS

This study enrolled 50 patients with a tumors <2 cm in diameter. Initially, we obtained three-dimensional (3-D) imaging from multidetector-row computed tomography (MD-CT) by volume rendering. It was projected on the patient's operative field with the clear visualization of lymph node (LN) through projector. Then, the dye of indocyanine green (ICG) was injected subdermally in the areola. Subcutaneous lymphatic channels draining from the areola to the axilla were visible by fluorescence imaging immediately. Lymphatic flow was reached after LN revealed on 3-D imaging. After incising the axillary skin on the point of LN mapping, SLN was then dissected under the guidance of fluorescence imaging with adequate adjustment of sensitivity and 3-D imaging.

RESULTS

Lymphatic channels and SLN were successfully identified by Photodynamic eye (PDE) in all patients. And the sites of skin incision also were identical with the LN being demonstrated by 3-D imaging in all patients. The mean number of SLN was 3.7. The image overlay navigation surgery was visually easy to identify the location of SLN from the axillary skin. There were no intra- or postoperative complications associated with SLN identification.

CONCLUSIONS

This combined navigations of fluorescence and 3-D imaging revealed more easy and effective to detect SLN intraoperatively than fluorescence imaging alone.

Erratum to: Axillary recurrence rate following negative sentinel node biopsy for invasive breast cancer: long-term follow-up

OBJECTIVE

Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection (ALND) as the staging procedure for breast cancer. SLN biopsy causes less morbidity and is more cost effective than complete ALND. Lymphatic mapping and SLN biopsy have a low false-negative rate, but long-term outcomes in large consecutive series of patients are unavailable.

METHODS

Retrospective review of a prospectively accrued institutional breast cancer database was performed. The initial mapping of 1,528 patients with invasive breast cancer that demonstrated negative sentinel node biopsy and no axillary dissection in 1,530 cases between January 1995 and June 2003 were collated and reviewed to achieve a long-term follow-up. These 1,528 patients were reviewed for follow-up time, local recurrences, distant metastases, and survival.

RESULTS

A total of 1,530 consecutively mapped invasive breast cancer cases had negative SLN biopsy and no ALND. The mean invasive tumor size of was 1.40 cm. Of patients, 1,212 (79.2%) underwent lumpectomy and 318 (20.8%) underwent mastectomy. Median follow-up was 63 months (range 0.1-144 months). There have been 4 (0.26%) cases presenting with local axillary recurrences, 54 (3.53%) cases presenting with local recurrences in the ipsilateral breast/chest wall, and 24 (1.57%) cases presenting with distant metastases.

CONCLUSION

These data confirm that SLN biopsy is an effective and safe alternative to ALND for detection of nodal metastases in patients with invasive breast cancer and validates its use as the standard tool for nodal staging.

A novel method for sentinel lymph node biopsy by indocyanine green fluorescence technique in breast cancer

We investigated the feasibility of sentinel lymph node (SLN) biopsy using indocyanine green (ICG) technique in 411 patients with early breast cancer at three institutes. ICG, a fluorescence source, and blue dye were injected into the subareolar area to enable real-time image-guided surgery and identification of SLN fluorescence after meticulous dissection. The subcutaneous lymphatic channels were precisely detected in all cases. SLN identification rate was 99% (408/411) with a mean of 2.3 nodes identified per patient. Thirty-nine cases (9.5%) had SLNs involved and all of them were ICG positive. Thus, the ICG technique has a high SLN identification rate comparable with that of the radioisotope method.

The use of touch preparation for the evaluation of sentinel lymph nodes in breast cancer

BACKGROUND

This study was undertaken to evaluate the accuracy of touch preparation (touch prep) in the evaluation of sentinel lymph nodes (SLNs).

METHODS

We performed a retrospective review of 402 breast cancer patients who underwent SLN biopsy.

RESULTS

A SLN was identified in 381 patients. Of 61 patients with a true positive result, 59 underwent axillary node dissection, and in 22 the SLN was the only node with metastases. Thirty-six (9.44%) had at least 1 false negative result. Twenty-five with a false negative results were due to macrometastases, with 17 (2.4%) false negatives occurring in patients with invasive ductal and 6 (5.5%) in those with invasive lobular histology, P = .04. Touch prep had an overall sensitivity of 62.89% and specificity of 98.94%.

CONCLUSIONS

Touch prep for the evaluation of SLNs in breast cancer compares favorably to reported results for frozen section. False negative findings are more likely with micrometastases and invasive lobular histology.

Pre-operative lymphoscintigraphy before sentinel lymph node biopsy for breast cancer

Pre-operative lymphoscintigram for axillary sentinel lymph node biopsy (SLNB) may not be required for successful SLNB. The 117 consecutive patients who underwent SLNB had pre-operative lymphoscintigraphy. The operating surgeon was blinded to the results of the lymphoscintigram before SLNB. After SLNB was complete, the surgeon was unblinded to the results of the lymphoscintigram; re-exploration carried out if more nodes were predicted on the lymphoscintigram. 116 patients (99%) had successful SLNB before unblinding. In 85 patients (73%), operative findings corresponded with scintigraphic findings. In 26 patients (22%), the lymphoscintigram predicted more sentinel nodes than had been found; further nodes were identified and excised in only 4 patients (3%). None were positive for cancer. SLNB was successful in 99% of cases without pre-operative lymphoscintigraphy. Only 3% of patients had further nodes identified as a result of the lymphoscintigram. Pre-operative lymphoscintigraphy does not improve the ability to perform axillary SLNB during breast cancer surgery.

Axillary recurrence rate following negative sentinel node biopsy for invasive breast cancer: long-term follow-up

OBJECTIVE

Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection (ALND) as the definitive nodal staging procedure for breast cancer. SLN biopsy has been proven to cause less morbidity and be more cost effective than complete ALND. Short-term follow-up has shown that lymphatic mapping and SLN have a low false-negative rate, but there is limited data demonstrating long-term outcomes within a large consecutive series of patients.

METHODS

Retrospective review of a prospective database of breast cancer patients at our institution was performed. The initial mapping of 1,530 patients with invasive breast cancer who demonstrated a negative sentinel node biopsy and no axillary dissection between January 1995 and June 2003 were collated and reviewed to achieve a long-term follow-up. These 1,530 patients were reviewed for follow-up time, local recurrences, distant metastases, and survival.

RESULTS

1,530 consecutively mapped invasive breast cancer patients had a negative SLN biopsy and no ALND. The mean invasive tumor size was 1.40 cm. Of 1,530 patients, 73% (1,121) underwent lumpectomy and 27% (409) underwent mastectomy. Mean follow-up was 4.92 years (range 0-12.0 years). There have been 4 (0.26%) patients presenting with local axillary recurrences, 54 (3.53%) patients presenting with local recurrences in the ipsilateral breast/chest wall, and 24 (1.57%) presenting with distant metastases.

CONCLUSION

These data confirm that SLN biopsy is an effective and safe alternative to ALND for detection of nodal metastases in patients with invasive breast cancer and should be used as the standard tool for nodal staging.

Sentinel lymph node mapping using near-infrared fluorescent methylene blue

Methylene blue (MB) is a safe, low cost, and common blue dye remaining a popular choice for sentinel lymph node (SLN) mapping. However, the blue-dyed SLN in deep animal tissue could be seen only after a surgical management. Here the fluorescence properties of MB were investigated using a fluorescence spectrometer and a wavelength-resolved fluorescence spectral in vivo imaging system, and MB has been demonstrated for near-infrared (NIR) fluorescence mapping of SLN. When MB was injected intradermally into the second row breast of a rabbit, the lymphatic flow and axillary SLN could be observed directly through the NIR fluorescence emitted from the MB trapped in the deep tissue, which would eliminate the need for surgical management, and this fluorescence without any radioactivity was retained in the SLN for hours. The node also could be identified synchronously by the blue color and fluorescence of the MB after a surgical management. Using MB NIR fluorescence for SLN mapping may have great advantages over the traditional method.

Noninvasive in vivo spectroscopic nanorod-contrast photoacoustic mapping of sentinel lymph nodes

Sentinel lymph node (SLN) biopsy has increasingly become important in axillary staging of breast cancer patients since SLN biopsy alleviates the postoperative complications of previously practiced axillary lymph node dissections. Nevertheless, the procedures of SLN biopsy using blue dye and radioactive substance are still intraoperative, and the latter methods are also ionizing. In this pilot study, we have proposed noninvasive in vivo spectroscopic photoacoustic (PA) SLN mapping using gold nanorods as lymph node tracers in a rat model. Gold nanorods have biocompatibility, high optical absorption, and easily tuned surface plasmon resonance peak wavelength.

Evaluation of breast lymphatic pathways with indocyanine green fluorescence imaging in patients with breast cancer

BACKGROUND

In patients with early breast cancer, sentinel lymph node biopsy (SLNB) has been emerging as a new standard of care. The use of SLNB with a blue dye is convenient and safe, but it requires a high level of technical skill. Recently, an instrument that can provide fluorescence imaging of lymphatic flow has been introduced. In the present study, we analyzed breast lymphatic pathways and discussed its potential as a modality to complement the use of SLNB with a blue dye.

METHODS

Thirty-seven consecutive patients with breast cancer were examined. To obtain fluorescence imaging, an invisible near-infrared fluorescence imaging system was used. After indocyanine green was subdermally injected in the subareolar site and at two sites around the tumor, the subcutaneous lymphatic drainage pathway (LDP) was observed.

RESULTS

In 27 (72.9%) of the patients, the number of LDP from the periareolar area was one or two. In 21(63.6%) of 33 patients with subdermal injection around the tumor, no LDP was observed from the peritumoral area. Lymphatic connection between the peritumoral area and the periareolar area was observed very frequently (91.7%). In 26 (70.3%) of the patients, multiple routes joined together and only one route was ultimately directed to the axilla. Significant correlation was seen between body mass index (BMI) and the transit time to the axilla after injection (p = 0.0038). Additionally, a significant correlation was seen between the number of LPD from the periareolar area and the distance between detected SLNs and the fluorescence line-disappearing point (p = 0.034).

CONCLUSIONS

This instrument can provide some important information, and can be an available and reliable navigator for SLNB with a blue dye.

Inorganic nanoparticles for predictive oncology of breast cancer

Nanoparticles (NPs) and nanosized objects are being incorporated rapidly into clinical medicine and particularly into the field of medical oncology, including breast cancer. A number of novel methods for breast cancer diagnosis and treatment, which are based on NPs and other nanodevices, are now available for translation into clinical practice. Computer tomography and MRI with iron-based magnetic NPs are promising methods for radiological detection of cancers. Semiconductor fluorescent NPs (quantum dots) are being developed for simultaneous detection and localization of multiple breast cancer biomarkers, enabling the personalization of therapeutic regimens for each patient. Additionally, inorganic NPs can be conjugated with tumor-specific ligands and used for tumor-selective delivery of chemotherapeutic or hormonal agents. NPs bearing tumor-targeted antibodies and oligonucleotides for anticancer gene therapy are a novel and rapidly developing therapeutic approach in oncology. Nab-paclitaxel and liposomal anthracyclines are US FDA-approved NP-based drug-delivery systems that have demonstrated at least equivalent efficacy and decreased toxicity compared with conventional chemotherapeutic agents used in the treatment of breast cancer. This review focuses on recent applications of NPs into predictive oncology of breast cancer with an emphasis placed on the role of inorganic nanosized objects in the diagnosis and treatment of this malignancy.

Sentinel node biopsy in pediatric soft tissue sarcomas of extremities

BACKGROUND

Sentinel Node Biopsy is an established staging technique in many adult malignancies. However, only few reports describe this procedure for the evaluation of regional lymph nodes in childhood and adolescents. Our experience with sentinel node biopsy in soft tissue sarcomas of extremities in children is reported.

METHODS

Seventeen children were evaluated with sentinel node biopsy between 2002 and 2007: 11 at initial surgery, 5 at primary re-excision, 1 at local relapse. The diagnosis was rhabdomyosarcoma in 5 and other soft tissue sarcomas in 12: Ewing/PNET sarcoma 6, epithelioid sarcoma 1, malignant peripheral-nerve-sheath tumor 1, undifferentiated sarcoma 1, myxoid liposarcoma 2, adult-type fibrosarcoma 1. Primary sites included lower limbs (8), upper limbs (9). Mapping of nodes was performed with lymphoscintigraphy plus intra-operative injections with blue-dye in 14 cases, with lymphoscintigraphy and intra-operative injections alone in 2 and 1, respectively.

RESULTS

Of the 17 lymphatic regions (9 axilla, 8 inguinal), 16 were identified with lymphoscintigraphy, 15 by intra-operative injections. Thirty-five lymph nodes were removed. Nodes were positive for metastasis in two patients with alveolar rhabdomyosarcoma and undifferentiated sarcoma. There were no complications. No further lymph node metastases were recognized either at diagnosis or during the follow-up (6-78 months).

CONCLUSIONS

Sentinel node biopsy was technically feasible, reliable, and free of complications. It could be an alternative to aggressive or random biopsies for extremity rhabdomyosarcoma and it can contribute to define those non-rhabdomyosarcoma soft tissue sarcomas that spread to regional nodes.

Identification of sentinel lymph node location based on body surface landmarks in early breast cancer patients

BACKGROUND

It would be extremely useful if the location of the sentinel lymph node in breast cancer could be identified based on body surface landmarks. However, the identification of the sentinel node location by using surface landmarks in many reports is based on empirical methodologies.

METHODS

We studied the distribution of the sentinel node location in 70 breast cancer patients based on the lateral line of the major pectoral muscle, the axillary skin fold that divides the trunk and the upper arm, and the nipple of the breast.

RESULTS

The location of the sentinel node could be predicted using an ellipse with a semi-major axis of 2.8 cm and a semi-minor axis of 2.2 cm with a probability of 95% for a patient with the mean body size.

CONCLUSION

Our data demonstrate that the location of the sentinel nodes can be predicted within a narrow area based on body landmarks.

Methylene blue dye--a safe and effective alternative for sentinel lymph node localization

Sentinel lymph node (SLN) biopsy has emerged as an effective diagnostic tool in axillary staging in breast cancer. The commonly used technique employs isosulfan blue/patent blue V combined with radioactive colloid tracer. Methylene blue (MB) is a less expensive and readily available alternative dye. The study evaluated the safety and efficacy of MB in SLN localization. A retrospective study of 329 patients with early breast cancer who had SLN localization as part of an ethically approved prospective evaluation study of SLN localization technique was carried out. Lymph node positive, tumors >2 cm on clinical and radiological evaluation, those with previous breast and axillary surgery, neo-adjuvant chemotherapy were excluded from the study. One hundred seventy three patients underwent SLN localization using 1 mL of 1% MB, and a combined MB-radio colloid tracer technique was used in the other 156 patients. Allocation to the groups was by simple randomization. Injection of the dye and radioisotope was into the subdermal plane in the sub-areolar region. Patients underwent breast conservation surgery or mastectomy with SLN directed four node axillary sampling +/- axillary clearance. The lymph node was examined by standard microscopy. There were no reported complications with the use of MB aside from temporary tattooing. The technique failed in eight patients giving an identification rate of 97.6%. Ten of the 258 (3.9%) patients had false-negative SLN, with negative predictive value of 96.1%, sensitivity of predicting further axillary disease of 73%, specificity of 87.3%, and overall accuracy of 85.7%. Reported adverse reaction to isosulfan blue/patent blue V varied from minor to severe anaphylactic reactions (1-3%) requiring vigorous resuscitation. Subdermal sub-areolar injection of MB is safe and effective readily available dye for SLN localization in axillary staging of breast cancer with no major adverse reaction.

Subareolar blue dye only injection sentinel lymph node biopsy could reduce the numbers of standard axillary lymph node dissection in environments without access to nuclear medicine

PURPOSE

The gold standard of axillary sentinel lymph node biopsy (SLNB) in breast cancer is the combination of radioactive colloid and blue dye injection. Worldwide, numerous hospitals without access to radioactive tracers still perform a routine complete axillary lymph node dissection (ALND). We retrospectively analyzed the false negative rate and identification rate of SLNB with injection of blue dye in the absence of radioactive colloid and compared the subareolar (SA) and the peritumoral (PT) injection.

PATIENTS AND METHODS

Two hundred and fourteen patients with clinically node negative unifocal breast cancer of up to 3 cm in size who underwent SLNB followed by ALND were included. Patent Blue V was injected at the SA site in 120 patients or at the PT site in 94 patients.

RESULTS

Thirty-seven (31%) patients in the SA group and 28 (29.8%) in the PT group were node-positive by ALND. The mean number of SLNs identified was 3.1 in the SA group and 1.6 in the PT group. The SLN identification rate was 91.7% for the SA group and 80.9% for the PT group (P = 0.017). The false negative rate was 3.6% in the SA group and 11.8% in the PT group (P = 0.032).

CONCLUSIONS

Our study shows an acceptable low false negative rate for the SA blue dye only injection and confirms the higher identification rate of SA versus PT localisation. This technique could have spared 67.5% (81 out of 120) of our patients the ALND and could replace ALND of early breast cancer patients in environments without access to nuclear medicine.

Validity of sentinel lymph node biopsy in Taiwanese breast cancer patients

BACKGROUND/PURPOSE

The clinical validity of sentinel lymph node (SLN) biopsy in Taiwanese breast cancer patients from 16 institutes in two consecutive periods was analyzed.

METHODS

Data from the initial period between January 3, 1999 and July 2004 and data from the later period after August 2004 to February 2005 were compared. Data on the use of a tracer, SLN identification, harvest and examination, false negative rate (FNR) and the number of patients spared axillary lymph node dissection (ALND) were analyzed.

RESULTS

A total of 3308 patients with clinical axilla negative breast cancer underwent SLN biopsies in 16 hospitals (11 in both periods and 5 in the period before August 2004). Comparison of data from the two periods revealed that in the later period, use of combined blue dye and isotope tracer increased from 40% to 80%, the 95% SLN biopsy success rate increased from 50% to 80%, hospitals conducting intraoperative SLN examination increased from 80% to 93%, and the 95% match to permanent section rate increased from 30% to 80%. In the initial period, eight hospitals had less than 7% FNR, while in the later period this had decreased to 4.1% in these hospitals. Another three hospitals had FNR greater than 7% in the initial period, which had decreased to 0% in the later period. Hospitals with more than 100 cases of SLN biopsy had an average 3.8% FNR, whereas hospitals with less than 100 cases of SLN biopsy experience had an 8.2% FNR (p < 0.01).

CONCLUSION

This study found that the SLN biopsy success rate increased after the use of combined tracers and with experience. FNR was controlled to within 5% among breast surgeons with accumulated experience exceeding 100 cases. It is recommended that ALND-sparing surgery be suspended temporarily in hospitals with FNR greater than 5%.

Clinical significance of skip metastasis in patients with gastric cancer

BACKGROUND

Metastasis appearing to bypass or skip tiers of lymph nodes (LNs) has been referred to as skip metastasis. The clinical impact of skip metastasis in gastric cancer remains unclear.

METHODS

In patients with gastric cancer, the clinicopathological features and postoperative prognoses of 21 patients with skip metastasis were evaluated and compared with findings in patients with group 1 (N1) or group 2 (N2) LN metastasis.

RESULTS

Of the 21 patients with skip metastasis, 9 patients had metastasis in the LN along the common hepatic artery (No. 8a), 8 patients had metastasis in the LN along the left gastric artery (No. 7), 2 patients had metastasis in LNs No. 7 and No. 8a, 1 patient had metastasis in the LN at the splenic hilum (No. 10), and 1 patient had metastasis in LN No. 10 and the LN along the splenic artery (No. 11). The mean diameter of the tumors in the patients with skip metastasis was 5.7 +/- 2.4 cm, which was significantly smaller than those in the N1 patients (7.9 +/- 4.1 cm) and N2 patients (9.3 +/- 4.6 cm). The incidence of serosal invasion, lymphatic vessel invasion, and peritoneal metastasis was lower in patients with skip metastasis compared with N2 patients. The 5-year survival rates were 70.2%, 62.0%, and 31.2% in patients with skip metastasis, patients with metastasis in group 1 LNs, and those with metastasis in group 2 LNs, respectively. The prognosis of patients with metastasis in group 2 LNs was significantly worse than that of patients with either skip metastasis (P = 0.0029) or metastasis in group 1 LNs (P < 0.0001).

CONCLUSION

Our data indicate that both the clinicopathological characteristics and the prognoses of patients with skip metastasis were similar to those of patients with N1 LN metastasis, but these features were not similar to those in patients with N2 LN metastasis. The sites of skip metastasis presented in the current study may be the key for applying the concept of the sentinel node in gastric cancer.

A dendrimer-based nanosized contrast agent dual-labeled for magnetic resonance and optical fluorescence imaging to localize the sentinel lymph node in mice

PURPOSE

To preoperatively and intraoperatively localize the sentinel lymph node (SLN), a single hybrid probe for MR and near infrared (NIR) optical imaging was synthesized and tested.

MATERIALS AND METHODS

A macromolecular MR/NIR optical contrast agent was synthesized based on a approximately 191 gadolinium-labeled contrast agent using generation-6 polyamidoamine dendrimer (G6), which is also labeled with 2 Cy5.5, an NIR fluorophore. After establishing the optimal dose, the agent was injected into mammary glands of 10 normal mice to examine the lymphatic drainage from the breast using a 3T clinical scanner. Immediately after the MRI scan, NIR optical imaging and image-guided surgery were performed to compare the two imaging modalities.

RESULTS

To consistently identify the SLNs, we needed to inject 25 microL of 30 mM [Gd] G6-Cy5.5. All SLNs could be easily identified and resected under NIR optical imaging-guided surgery. Although external NIR optical imaging failed to identify SLNs close to the injection site due to shinethrough, MR lymphography (MRL) consistently identified all SLNs regardless of their location.

CONCLUSION

We have successfully synthesized and tested a dual labeled MR/NIR optical hybrid contrast agent, G6-Cy5.5 for reoperative and intraoperative localization of SLNs.

Is Routine Sentinel Lymph Node Biopsy Indicated in Women Undergoing Contralateral Prophylactic Mastectomy? Magee-Womens Hospital Experience

INTRODUCTION

The routine use of sentinel node biopsy (SLNB) at the time of prophylactic mastectomy remains controversial. This retrospective study was undertaken to determine if SLNB is justified in patients undergoing CPM.

METHODS

Between 1999 and 2004, 155 patients underwent contralateral prophylactic mastectomy (CPM) at the Magee-Womens Hospital of University of Pittsburgh Medical Center. Eighty patients (51.6%) had SLNB performed at the time of CPM. The therapeutic mastectomy and the CPM specimens were evaluated for histopathology. Goldflam's classification was used to determine the risk of malignancy in the CPM specimens.

RESULTS

Pathology in the therapeutic mastectomy specimens included 105 (68%) invasive carcinomas and 50 (32%) in-situ carcinomas. Multicentricity and/or multifocality were reported in 49.7%, and 70% were estrogen receptor positive. Two invasive breast cancers and three cases of DCIS were diagnosed in 155 CPM specimens (n = 5, 3.2%). The median number of SLN identified was 2 (range 1-6) from the CPM axilla. Two patients had positive SLNB for metastatic carcinoma (n = 2/80, 2.5%) with no primary tumor identified in the prophylactic mastectomy specimen. In both patients the therapeutic mastectomy was for recurrent invasive carcinoma in patients with a prior history of axillary node dissection. Occult carcinoma was found in five prophylactic mastectomy specimens: two invasive and three DCIS. Only 1 out of the 75 patients not undergoing SLNB at the time of their initial surgery would have required axillary staging for a previously undiagnosed invasive cancer in the CPM specimen on final pathology. Of all 155 patients undergoing CPM, only 4 (2.5%) had identified final pathologic findings where axillary staging with SLNB was beneficial. There was no evidence of arm lymphedema in any patient who had undergone CPM and SLNB at a median follow-up of 24 months.

CONCLUSION

Although SLNB is a minimally invasive method of axillary staging, this retrospective study does not support its routine use in patients undergoing CPM.

Intraoperative imprint cytology of sentinel lymph nodes in breast cancer: initial experience and lessons learnt in establishing a new practice

AIMS

The initial 18 months experience of performing intraoperative imprint cytology for patients with breast cancer undergoing sentinel lymph node biopsy is described for a single institution. The learning process is compared with published results from institutions with many years of experience in order to assess progress in reaching those ideal results, and the methodology used by these institutions is reviewed.

METHODS

A retrospective review was undertaken of the intraoperative imprint cytology results from 103 patients with breast cancer (yielding a total of 170 lymph nodes) who underwent imprint cytology of their sentinel lymph node. The intraoperative imprint cytology results were compared with the final histopathological results. Details regarding the primary tumour characteristics and metastatic deposit size were recorded.

RESULTS

The sensitivity for imprint cytology was 31.1%, with a specificity of 100% and overall accuracy of 77.8%. The sensitivity for detecting macrometastases (>2 mm diameter) was 61.9% and the sensitivity for micrometastases (<2 mm diameter) and including isolated tumour cells was 4.2%.

CONCLUSIONS

The differences in sensitivity in comparison with many studies in the literature are multifactorial, and include technical aspects, such as the methodology used in the final histopathological and intraoperative evaluation of the sentinel lymph nodes, interpretative difficulties, and much lower case numbers. Furthermore, these numbers represent early experience and methods to improve sensitivity and overall accuracy are detailed in this paper.

Sentinel node detection in breast cancer using contrast-enhanced sonography with 25% albumin--Initial clinical experience

PURPOSE

To determine the clinical usefulness of a sentinel lymph node (SLN) identification technique using contrast-enhanced sonography (CEUS) with 25% albumin.

METHODS

The subjects were 23 women with breast cancer. Each was injected subcutaneously with 5 ml of 25% albumin solution as a negative contrast agent directly superficial to the breast tumor. The area was massaged, and the inferior axillary hairline was examined continuously using gray-scale sonography with a 7.5- or 10-MHz transducer. Any contrast-enhanced lymph node was considered a CEUS-detected SLN, was differentiated from other level I and II nodes, and was resected and pathologically assessed.

RESULTS

In all 23 patients, 1 or 2 CEUS-detected SLNs (mean, 1.3 SLNs) were identified. Their sizes ranged from 5 mm to 25 mm (mean, 11.3 mm), and their depths (from the skin surface) ranged from 5mm to 20 mm (mean, 12.6 mm). Pathologic examination revealed a metastasis in 5 of the 23 patients, all in CEUS-detected SLNs.

CONCLUSION

In a clinical study using CEUS with 25% albumin, contrast-enhanced nodes were identified in all subjects. The pathologic findings suggested that any metastatic nodes observed were SLNs, indicating that this technique may represent a new modality for SLN identification.

NATIONAL BREAST CANCER AUDIT: OVERVIEW OF INVASIVE BREAST CANCER MANAGEMENT

BACKGROUND

The National Breast Cancer Audit is an initiative of the Breast Section of the Royal Australasian College of Surgeons collecting surgical information in early breast cancer. It is managed in conjunction with the Australian Safety and Efficacy Register of New Interventional Procedures - Surgical. An overview of results for invasive breast cancer from January 1999 until December 2004 is presented to provide preliminary data for participating surgeons.

METHODS

Invasive breast cancer cases were retrieved from the National Breast Cancer Audit database for the 274 participating breast surgeons in Australia and New Zealand. Data for a variety of clinical parameters were analysed to provide an overview of the diagnostic, histological, surgical and adjuvant therapy management issues.

RESULTS

There were 25,026 cases of invasive breast cancer. Annual percentages of mammographically detected cancers from 1999 to 2004 did not differ significantly. Breast-conserving surgery rates also remained stable at 60%. Margins were involved in 5% of patients; an additional 9% had final margins of less than 1 mm. Radiotherapy followed breast-conserving surgery in most cases (86%). Patients undergoing mastectomy with large tumours (>5 cm) underwent radiotherapy in 71% of cases. When at least four lymph nodes were positive, radiotherapy followed mastectomy in the majority (75%) of cases. The most frequently carried out axillary procedure was a level 2 dissection. Chemotherapy was received by 78% of oestrogen receptor negative, axillary node positive, postmenopausal patients. Tamoxifen was used in the majority (83%) of oestrogen receptor positive cases.

CONCLUSION

Surgeons contributing their invasive breast cancer data show a high quality of treatment. Some further improvement may be possibly related to excision margins and tamoxifen prescription for oestrogen receptor negative cancers. Chemotherapy prescription might also warrant further investigation.

Ex vivo sentinel lymph node mapping in colon cancer: improving the accuracy of pathologic staging?

BACKGROUND

A subset of patients with colon cancer staged by conventional methods have occult micrometastases and do not receive adjuvant chemotherapy. Sentinel lymph node (SLN) mapping and staining by immunohistochemistry is a technique that may identify such occult micrometastases, thereby upstaging patients with positive findings. The purpose of this study was to determine whether ex vivo SLN mapping in colon cancer could be applied successfully to patients at our institution.

METHODS

Seventeen patients with intraperitoneal colon tumors undergoing resection were studied prospectively. SLNs were identified as the first blue stained node(s) after ex vivo peritumoral injection of isosulfan blue dye. Additional lymph nodes were harvested and processed in accordance with standard pathologic evaluation for colon cancer. All nodes were examined after routine hematoxylin and eosin (H&E) staining. SLNs that were negative on H&E were analyzed further by multilevel sectioning and immunohistochemistry staining using anticytokeratin monoclonal antibody.

RESULTS

Of the 17 study patients, SLNs were identified in 16 (94%) cases. The SLN was the only positive node in 3 patients. An identified SLN was positive (by H&E) in all patients with associated positive non-SLN nodes. The average number of nodes retrieved per patient was 16 (range, 4-54). Overall, SLNs accurately reflected the status of the entire lymph node basin in 16 (94%) patients. Two (12%) patients with negative nodes by H&E potentially were upstaged after further SLN analysis. The negative predictive value for SLN mapping was 89%.

CONCLUSIONS

The ex vivo technique of SLN mapping for colon cancer is feasible. In the current study, SLN results were concordant with non-SLNs in the majority of patients. Furthermore, this technique may have upstaged 2 (12%) patients. Whether this ultimately will affect overall survival has yet to be determined.

Sentinel lymph node dissection for breast cancer: how many nodes are enough and which technique is optimal?

BACKGROUND

Controversy exists in sentinel lymph node (SLN) mapping in breast cancer regarding the appropriate number of nodes to remove and the best technique for identification of the SLNs.

METHODS

A retrospective chart review from January of 1999 to January of 2004 was performed for all patients undergoing a SLN biopsy examination who had at least 1 positive SLN.

RESULTS

We identified 167 patients. A mean of 4.4 SLNs were removed per patient. All of the positive SLNs were identified by node 6. Radiotracer used alone identified 19 positive nodes (11.4%) and blue dye used alone identified 14 positive nodes (8.4%).

CONCLUSIONS

Our data show that 100% of positive SLNs are found by 6 nodes removed, thereby supporting the concept that the SLN dissection may not be complete by removing only 1 or 2 nodes or only the hottest node. The use of blue dye or radiotracer alone can contribute to the overall false-negative rate.

Sentinel node biopsy in patients with breast cancer—evaluation of exposureto radiation of medical staff

AIM

To measure the absorbed doses of radiation to hands of medical staff performing sentinel node biopsy in breast cancer patients.

METHODS

The study was conducted in 2004, during sentinel node biopsies in 13 breast cancer patients (T1/T2N0). Sentinel nodes were identified with the use of combined radiotracer/blue dye technique (lymphoscintigraphy--99mTc on albumin carrier, surgery after 24 h; blue dye; intraoperative detection of gamma radiation). Highly sensitive thermoluminescent dosimeters (TLD) made of LiF were used to assess the absorbed doses of radiation during the procedure. During lymphoscintigraphy and during surgical procedure a total of 57 TLDs was placed on different parts of hands of medical staff.

RESULTS

Maximal dose recorded during lymphoscintigraphy by TLDs placed on the hands of the physician injecting the radiotracer was 164 microSv. Mean recorded doses were higher for non-dominant hand, especially for distal parts of the index finger, third finger and thumb. During the surgical procedure, TLDs placed on the hands of medical staff recorded much lower doses of radiation than during lymphoscintigraphy. The highest dose was recorded by TLD placed on the pulp of the dominant hand index finger (22 microSv) of the operating surgeon. Mean doses recorded by TLDs placed on the hands of the operating surgeon ranged from 2 to 8 microSv. The absorbed dose of radiation to hands of the scrub nurse was similar to that absorbed to hands of the operating surgeon.

CONCLUSION

The maximum recorded dose during sentinel node biopsy in this study was 2200 times smaller than current 1-year dose limit.

Delivery of gadolinium-labeled nanoparticles to the sentinel lymph node: comparison of the sentinel node visualization and estimations of intra-nodal gadolinium concentration by the magnetic resonance imaging

Sentinel node imaging is commonly performed prior to surgery for breast cancer and melanoma. While current methods are based on radio-lymphoscintigraphy, MR lymphangiography (MRL) offers the benefits of better spatial resolution without ionizing radiation. However, the optimal nanoparticle for imaging the sentinel nodes remains unclear. Gadolinium-labeled (Gd) contrast agents ranging in diameter from <1 to 12 nm were evaluated to determine which size provides the most rapid and most concentrated delivery of contrast agent to the lymph nodes in a mouse model of lymphatic metastases. Specifically, PAMAM-G2, -G4, -G6 and -G8, and DAB-G5 Gd-dendrimer agents, as well as Gadomer-17 and Gd-DTPA, were compared. Among these agents, the G6 Gd dendrimer depicted the lymphatics and lymph nodes with the highest peak concentrations and this occurred 24-36 min post-injection (p<0.01; all except G8). Based on ex vivo concentration phantoms, high accumulations of Gd(III) ions occurred within lymph nodes (1.7-4.4 mM Gd/270-680 ppm Gd) with high target to background ratios (>100). These concentrations are sufficient to contemplate the use of Gd-neutron capture therapy of regional lymph nodes. Thus, when injected interstitially, the PAMAM-G6 Gd dendrimer not only provides excellent opacification of sentinel lymph nodes, but also provides the potential for targeted therapy of sentinel lymph nodes.