Factors affecting failed localisation and false-negative rates of sentinel node biopsy in breast cancer--results of the ALMANAC validation phase

Limited effectiveness of patent blue dye in addition to isotope scanning for identification of sentinel lymph nodes: Cross-sectional real-life study in 1024 breast cancer patients

BACKGROUND

Although morbidity is reduced when sentinel lymph node (SLN) biopsy is performed with dual isotopic and blue dye identification, the effectiveness of adding blue dye to radioisotope remains debated because side effects including anaphylactic reactions.

PATIENTS AND METHODS

Using data from a prospectively maintained database, 1884 lymph node-negative breast cancer patients who underwent partial mastectomy with SLN mapping by a dual-tracer using patent blue dye (PBD) and radioisotope were retrospectively studied between January 2000 and July 2013. Patients with tumors <3 cm and with >1 node detected by one of the two techniques (N = 1024) were included in this real-life cross-sectional study.

RESULTS

Among the 1024 patients, 274 had positive SLN detected by isotopic and/or PBD staining. Only 4 patients having no detectable radioactivity in the axilla had SLN identified only by PBD staining (blue-only) while 26 patients had SLN only identified by isotopic detection (hot-only) illustrating failure rates of 9.5% (26/274) and 1.5% (4/274), respectively. Among these four patients, two had negative lymphoscintigraphy. Therefore, the contribution of PBD to metastatic nodes identification was relevant for only 2/274 patients (0.8%). Three patients (0.3%) had an allergic reaction with PBD, and anaphylactic shock occurred in two cases (0.2%).

CONCLUSIONS

The added-value of PBD to reduce the false-negative rate of SLN mapping is only limited to the rare cases in which no radioactivity is detectable in the axilla (<1%). When a radioisotope mapping agent is available, the use of PBD should be avoided, because it can induce anaphylaxis.

Impact of Body Mass Index on Clinical Axillary Nodal Assessment in Breast Cancer Patients

BACKGROUND

More than one-third of American adults are obese, and an elevated body mass index (BMI) is postulated to reduce the sensitivity of the clinical evaluation of the axilla. Clinical nodal examination is important in allocating breast cancer patients to appropriate axillary management. This study sought to determine whether BMI influences the rate of nodal positivity in women designated clinically as node-negative (cN0) by physical examination.

METHODS

Breast cancer patients deemed cN0 who underwent sentinel lymph node biopsy (SLNB) from February 2006 to December 2011 were identified from a prospectively maintained database. Clinicopathologic features including BMI and axillary surgery results were recorded and compared among pathologically node-negative and node-positive patients.

RESULTS

Overall, 5142 cN0 patients underwent 5262 SLNB procedures during the study period. Nearly one-third of the patients (28 %) were obese (BMI, >30 kg/m(2)). A positive SLN was identified in 25 % of the patients, and 84 % proceeded to axillary lymph node dissection. Predictors of SLN positivity included younger age, larger tumor size, high nuclear grade, multifocality, and lymphovascular invasion. An increased BMI did not correlate with a higher likelihood of SLN positivity (p = 0.6). The likelihood of cN0 patients having a high burden of axillary metastases (>3 positive nodes) was 4 % overall and, similarly, did not differ according to BMI (p = 0.4).

CONCLUSION

Elevated BMI was not associated with a higher likelihood of SLN positivity or heavy nodal disease burden among women staged as cN0 by physical exam. These findings indicate that physical examination is appropriate and sufficient for preoperative axillary evaluation of women undergoing initial surgery regardless of patient BMI.

Technetium-99m-labeled rituximab for use as a specific tracer of sentinel lymph node biopsy: a translational research study

PURPOSE

We aimed to develop and translate a CD20-antigen-targeted radiopharmaceutical, Technetium-99 m-labeled (99mTc) rituximab, for sentinel lymph node (SLN) detection.

METHODS

99mTc-rituximab was synthesized and tested for stability in human serum. The binding affinity to CD20 was evaluated in Raji cells by flow cytometric analysis. Biodistribution and sentinel node mapping were carried out in bal b/c mice. Eighty-five patients with breast cancer participated in this study. Dynamic sentinel lymphoscintigraphy was first assessed in 12 patients before planar lymphoscintigraphy was assessed in a larger cohort. All patients underwent sentinel lymph node biopsy (SLNB), followed by axillary lymph node dissection.

RESULTS

The cell-binding study showed that 99mTc-rituximab possessed compatible affinity to human CD20. In the mechanism study, 99mTc-labeled anti-mouse CD20 monoclonal antibodies could bind to mouse CD20 and accumulate in the SLN with 2.62±1.25 % of the percentage of injected activity, which could be blocked by excessive unlabeled antibody. Low uptake of non-sentinel nodes and fast clearance from the injection site were observed in the mice. Sentinel nodes were identified in 82 of 85 breast cancer patients (96.5%) by lymphoscintigraphy and SLNB. The sensitivity, specificity, and accuracy were 96.8% (30/31), 100% (51/51), and 98.8% (81/82), respectively.

CONCLUSION

99mTc-rituximab, specifically binding to CD20, met most of the requirements of an ideal sentinel mapping agent for use in clinical settings.

Endometrial and cervical cancer patients with multiple sentinel lymph nodes at laparoscopic ICG mapping: How many are enough?

PURPOSE

The adoption of a sentinel lymph node (SLN) algorithm and the presence of high bilateral detection rates have been associated with increased accuracy of SLN mapping in cervical and endometrial cancer patients. In this context, the significance of the number of SLNs removed has not yet been investigated. The aim of this study was to evaluate (a) whether or not a higher SLN removal count is associated with a reduced false-negative rate and (b) which clinical factors correlate with the number of SLNs removed.

METHODS

Patients with cervical or endometrial cancer who underwent SLN mapping with bilateral SLN detection followed by lymphadenectomy were evaluated retrospectively. On the basis of the mean number of the SLNs removed, the patients were divided in two groups: Group 1 included patients with up to 3 SLNs removed and Group 2 included patients with more than 3 SLNs removed. Factors predicting a higher SLN count were evaluated using univariate and multivariate analysis.

RESULTS

Eighty-four patients met the inclusion criteria. The two groups consisted of 42 patients each and differed only by the median SLN count. Two endometrial cancer patients in Group 1 had false-negative pelvic SLNs and isolated para-aortic metastases; no false-negative SLNs were recorded in Group 2 (p = n.s.). The results of multivariate analysis indicted that the number of SLNs removed was influenced only in cases where the operating surgeon had performed more than 20 laparoscopic ICG SLN mappings.

CONCLUSIONS

A higher SLN count does not seem to increase the accuracy of SLN mapping in cervical and endometrial cancer patients.

Diagnostic Performance of Indocyanine Green-Guided Sentinel Lymph Node Biopsy in Breast Cancer: A Meta-Analysis

Background

The diagnostic performance of indocyanine green (ICG) fluorescence-guided sentinel lymph node biopsy (SLNB) for the presence of metastases in breast cancer remains unclear.

Objective

We performed a meta-analysis to investigate the diagnostic performance of ICG-guided SLNB.

Methods

Eligible studies were identified from searches of the databases PubMed and EMBASE up to September 2015. Studies that reported the detection rate of ICG fluorescence-guided SLNB with full axillary lymph node dissection and histological or immunohistochemical examinations were included. A meta-analysis was performed to generate pooled detection rate, sensitivity, specificity, false negative rate, diagnostic odds ratio (DOR) and a summary receiver operator characteristic curve (SROC).

Results

Nineteen published studies were included to generate a pooled detection rate, comprising 2594 patients. The pooled detection rate was 0.98 (95% confidence interval [CI], 0.96–0.99). Six studies finally met the criteria for meta-analysis, which yielded a pooled sensitivity of 0.92 (95% CI, 0.85–0.96), specificity 1 (95% CI, 0.97–1), and DOR 311.47 (95% CI, 84.11–1153.39). The area under the SROC was 0.9758. No publication bias was found.

Conclusion

ICG fluorescence-guided SLNB is viable for detection of lymph node metastases in breast cancer. Large-scale randomized multi-center trials are necessary to confirm our results.

Article Commentary: Surgical Management of the Axilla in Breast Cancer

This article offers a review of the literature on current surgical management of the axilla in breast cancer. This includes the decision-making process involved in clinically node-negative patients versus clinically node-positive patients, with discussion of the indications for sentinel lymph node biopsy versus axillary dissection. It also examines the surgical axillary management of patients who receive neoadjuvant chemotherapy. This article will help update practicing surgeons on the evolving research and guidelines for the management of breast cancer axillary disease.

Evaluation of sentinel lymph node biopsy after previous breast surgery for breast cancer: GATA study

AIM

Sentinel lymph node (SLN) biopsy was recently recommended after prior breast tumour surgery and lymphadenectomy is not the gold standard anymore for nodal staging after a lesion's removal. The purpose of our study was to evaluate the good practices of use of SLN biopsy in this context.

PATIENTS AND METHODS

From 2006 to 2012, 138 patients having undergone a surgical biopsy without prior diagnosis of an invasive carcinoma with a definitive histological analysis in favour of this diagnosis were included in a prospective observational multicentric study. Each patient had a nodal staging following SLN biopsy with subsequent systematic lymphadenectomy.

RESULTS

The detection rate of SLN was 85.5%. The average number of SLNs found was 1.9. The relative detection failure risk rate was multiplied by 4 in the event of an interval of less than 36 days between the SLN biopsy and the previous breast surgery, and by 9 in the event of using a single-tracer detection method. The false negative rate was 6.25%. The prevalence of metastatic axillary node involvement was 11.6%. In 69% of cases only the SLN was metastatic. The post-operative seroma rate was 19.5%.

CONCLUSION

Previous conservative breast tumour surgery does not affect the accuracy of the SLN biopsy. A sufficient interval of greater than 36 days between the two operations could allow to improve the SLN detection rate, although further studies are needed to validate this statement.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00293865.

How Often Does Neoadjuvant Chemotherapy Avoid Axillary Dissection in Patients With Histologically Confirmed Nodal Metastases? Results of a Prospective Study

BACKGROUND

In breast cancer patients with nodal metastases at presentation, false-negative rates lower than 10 % have been demonstrated for sentinel node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) when three or more negative sentinel nodes (SLNs) are retrieved. However, the frequency with which axillary dissection (ALND) can be avoided is uncertain.

METHODS

Among 534 prospectively identified consecutive patients with clinical stages 2 and 3 cancer receiving NAC from November 2013 to November 2015, all biopsy-proven node-positive (N+) cases were identified. Patients clinically node-negative after NAC were eligible for SLNB. The indications for ALND were failed mapping, fewer than three SLNs retrieved, and positive SLNs.

RESULTS

Of 288 N+ patients, 195 completed surgery, with 132 (68 %) of these patients eligible for SLNB. The median age was 50 years. Of these patients, 73 (55 %) were estrogen receptor-positive (ER+), 21 (16 %) were ER- and human epidermal growth factor receptor-2-positive (HER2+), and 38 (29 %) were triple-negative. In four cases, SLNB was deferred intraoperatively. Among 128 SLNB attempts, three or more SLNs were retrieved in 110 cases (86 %), one or two SLNs were retrieved in 15 cases (12 %), and failed mapping occurred in three cases (2 %). In 66 cases, ALND was indicated: 54 (82 %) for positive SLNs, 9 (14 %) for fewer than three negative SLNs, and 3 (4 %) for failed mapping. Persistent disease was found in 17 % of the patients with fewer than three negative SLNs retrieved. Of the 128 SLNB cases, 62 (48 %) had SLNB alone with three or more SLNs retrieved. Among 195 N+ patients who completed surgery, nodal pathologic complete response (pCR) was achieved for 49 %, with rates ranging from 21 % for ER+/HER2- to 97 % for ER-/HER2+ cases, and was significantly more common than breast pCR in ER+/HER2- and triple-negative cases.

CONCLUSIONS

Nearly 70 % of the N+ patients were eligible for SLNB after NAC. For 48 %, ALND was avoided, supporting the role of NAC in reducing the need for ALND among patients presenting with nodal metastases.

Clinical and Pathological Factors Affecting the Sentinel Lymph Node Metastasis in Patients with Breast Cancer

Sentinel lymph node biopsy has become the routine procedure in axilla-negative breast cancer patients at most medical centers for axillary staging and local control in the recent years. Sentinel lymph node is the only focus in axillary lymph metastasis in a large portion of patients. In our trial, we investigated the clinical and pathological factors that affect the positive status of sentinel lymph node. We included 89 patients, who underwent sentinel lymph node biopsy (SLNB) with methylene blue and/or technetium-99 m Sulphur Colloid due to early-stage breast cancer. Five patients, in whom SLN was not detected and who underwent axillary dissection, were excluded from the trial. The patient age, location of the tumor, the type of the tumor, the T stage by the TNM staging system, the histological grade and type of the tumor, the status of multifocality, the lymphovascular invasion status of the tumor, and the ER, PR, and HER-neu2 status were recorded. The median age of the 89 patients was 52, 9 (±10) years. Fifty-seven (64 %) and 32 (36 %) of the 89 patients were detected to have positive and negative SLN, respectively. Assessing the SLNB positivity and the patient age, tumor size, tumor grade, multifocality, tumor localization, the T stage by the TNM staging, the ER/PR positivity/negativity, and the HER/neu2 and p53 status, the data revealed no statistically significant results with respect to SLN metastasis. The lymphovascular invasion status (LVI) was observed to statistically affect the SLN positivity (p < 0.016). We showed that LVI could be an important marker in predicting the SLN positivity in patients with axilla-negative early-stage breast cancer. In the future, upon introduction of new biomarkers and with relevant studies, it may be possible to predict the SLNB status of patients at an adequately high accuracy and a low risk.

The Role of Blue Dye in Sentinel Node Detection for Breast Cancer: A Retrospective Study of 203 Patients

OBJECTIVE

We aimed at examining the potential benefits of blue dye in sentinel node biopsy (SNB) in comparison with its proven drawbacks.

PATIENTS AND METHODS

In 2007, 203 T1 primary breast carcinomas had been operated on in our institute. The patients had undergone a lumpectomy and SNB. Sentinel node (SN) detection was exclusively isotopic (ISO) in 77 patients and performed with blue dye combined with a radioactive isotope (COMBI) in 126 patients. We compared the number of SNs and the rate of SN positivity in both groups.

RESULTS

The detection rate was 99% in both groups: 76/77 in the ISO group and 125/126 in the COMBI group. The mean number of SNs was 2.14 and 1.91 in the ISO group and the COMBI group, respectively (difference not significant (NS)). SN positivity was found in 26.1% and 24.6% in the ISO group and the COMBI group, respectively (NS). Only 1 SN had been removed in 26% of the patients in the ISO group versus 45.2% of the patients in the COMBI group (p = 0.004). No significant differences were observed in the tumor characteristics.

CONCLUSION

The systematic use of patent blue dye combined with isotopic detection does not appear to increase the overall performance of the SNB technique in this retrospective study.

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.

Impact of Tumor Localization and Method of Preoperative Biopsy on Sentinel Lymph Node Mapping After Periareolar Nuclide Injection

BACKGROUND

To evaluate whether tumor localization and method of preoperative biopsy affect sentinel lymph node (SLN) detection after periareolar nuclide injection in breast cancer patients.

METHODS AND FINDINGS

767 breast cancer patients were retrospectively included. For lymphscintigraphy periareolar nuclide injection was performed and the SLN was located by gamma camera. Patient and tumor characteristics were correlated to the success rate of SLN mapping. SLN marking failed in 9/61 (14.7%) patients with prior vacuum-assisted biopsy and 80/706 (11.3%) patients with prior core needle biopsy. Individually evaluated, biopsy method (p = 0.4) and tumor localization (p = 0.9) did not significantly affect the SLN detection rate. Patients with a vacuum-assisted biopsy of a tumor in the upper outer quadrant had a higher odds ratio of failing in SLN mapping (OR 3.8, p = 0.09) compared to core needle biopsy in the same localization (OR 0.9, p = 0.5).

CONCLUSIONS

Tumor localization and preoperative biopsy method do not significantly impact SLN mapping with periareolar nuclide injection. However, the failure risk tends to rise if vacuum-assisted biopsy of a tumor in the upper outer quadrant is performed.

Sentinel lymph node identification using superparamagnetic iron oxide particles versus radioisotope: The French Sentimag feasibility trial

BACKGROUND AND OBJECTIVES

The French Sentimag feasibility trial evaluated a new method for the localization of breast cancer sentinel lymph node (SLN) using Sienna+®, superparamagnetic iron oxide particles, and Sentimag® detection in comparison to the standard technique (isotopes ± blue dye).

METHODS

We conducted a prospective multicentric paired comparison trial on 115 patients. SLN localization was performed using both the magnetic technique and the standard method. Detection rate and concordance between magnetic and standard tracers were calculated. Post-operative complications were assessed after 30 days.

RESULTS

Results are based on 108 patients. SLN identification rate was 98.1% [93.5-99.8] for both methods, 97.2% [92.1-99.4] for Sienna+® and 95.4% [89.5-98.5] for standard technique. A mean of 2.1 SLNs per patient was removed. The concordance rate was 99.0% [94.7-100.0%] per patient and 97.4% [94.1-99.2] per node. Forty-six patients (43.4%) had nodal involvement. Among involved SLNs, concordance rate was 97.7% [88.0-99.9] per patient and 98.1% [90.1-100.0] per node.

CONCLUSIONS

This new magnetic tracer is a feasible method and a promising alternative to the isotope. It could offer benefits for ambulatory surgery or sites without nuclear medicine departments. J. Surg. Oncol. 2016;113:501-507. © 2016 Wiley Periodicals, Inc.

[Focus on methods for detection of sentinel nodes in breast cancer]

The sentinel node procedure (GS) is the recommended technique for axillary surgical exploration in localized breast cancer with no clinical or radiological lymph node involvement. This surgical technique is based on a dual isotope and colorimetric detection. Although it allows a significant reduction in morbidity compared to axillary dissection (CA), this procedure induces a number of organizational constraints, in particular for the radioisotope injection. Specially for this reason, other GS methods have emerged in recent years, some of which appear promising (detection by fluorescence and magnetic iron). The objective of this paper was to carry out a synthesis of the reference method of detection (radioisotope) GS and analyze the recent literature on new detection methods.

Indocyanine green fluorescence mapping for sentinel lymph node biopsy in early breast cancer

INTRODUCTION

A recent feasibility study (ICG-10) has confirmed high sensitivity of ICG fluorescence mapping for sentinel SLN detection in early breast cancer with 95% of nodes both blue and fluorescent. This follow-on study has specifically evaluated a combination of ICG and blue dye for SLN localization.

METHODS

Fifty consecutive patients (49 female; 1 male) with unilateral clinically node negative invasive (37) and non-invasive (13) breast cancer underwent SLN biopsy with blue dye and ICG. Median patient age was 48 years and median invasive tumour size 19 mm for primary surgical patients. All patients had a normal pre-operative axillary ultrasound. Nodal and procedural detection rates were calculated for ICG alone and in combination with blue dye.

RESULTS

A total of 87 nodes were retrieved with an average nodal count of 1.8 per patient (range 1-4). Eighty four nodes were blue and fluorescent and 3 fluorescent only. Nodal detection rates for ICG alone and combined with blue dye were 100% (87/87) and 96% (84/87) respectively. Metastases were present in 18 nodes (all blue and fluorescent) with 10 patients node positive overall (20%). The procedural detection rate for blue dye and ICG was 96% (48/50) and 2 patients had fluorescent only nodes which were deemed sentinel (4%).

CONCLUSION

Fluorescent imaging with ICG is a sensitive, valuable and safe method for SLN biopsy. A combination of blue dye and ICG is useful dual approach when radioisotope is unavailable. ICG has the potential to be a sole tracer agent with improved patient convenience and costs.

Robotic blue-dye sentinel lymph node detection for endometrial cancer - Factors predicting successful mapping

OBJECTIVE

Sentinel lymph node (SLN) mapping has emerged as a viable option for the treatment of patients with endometrial cancer. We report our initial experience with SLN mapping algorithm, and examine the factors predicting successful SLN mapping.

METHODS

We analyzed all data recorded in our institute on robotic blue-dye SLN detection mapping from the time it was first introduced to our department in January 2012-December 2014. Data included patient demographics, SLN allocation, operating room times, and pathology results.

RESULTS

During the study period, 74 patients had robotic assisted surgery for endometrial cancer with attempted SLN mapping. SLN was found overall in 46 patients (62.1%). At first, SLN was detected in only 50% of cases, but after performing 30 cases, detection rates rose to 84.6% (OR = 3.34, CI 1.28-8.71; p = 0.003). Univariate analysis showed a higher detection rate with methylene blue than patent blue dye, 74.3% vs. 52.3% (OR = 2.744, 95% CI 1.026-7.344; p = 0.042). In multivariate analysis, high body mass index (BMI) was associated with failed mapping (OR = 0.899; 95% CI 0.808-1.00), as was the presence of lymph-vascular space invasion (LVSI) (OR = 0.126; 95% CI 0.24-0.658) and few cases per surgeon (OR = 1.083, 95% CI 1.032-1.118). Factors related to uterine pathology itself, including tumor histology, grade, method of diagnosis, the presence of an endometrial polyp, and lower uterine segment involvement were not found to be associated with successful mapping.

CONCLUSIONS

Surgeon experience, BMI and LVSI may affect the success rate of SLN mapping for endometrial cancer. These factors should be investigated further in future studies.

Accurate evaluation of axillary sentinel lymph node metastasis using contrast-enhanced ultrasonography with Sonazoid in breast cancer: a preliminary clinical trial

Breast cancer is the most common type of cancer in women. The 5-year survival rate in patients with breast cancer ranges from 74 to 82 %. Sentinel lymph node biopsy has become an alternative to axillary lymph node dissection for nodal staging. We evaluated the detection of the sentinel lymph node and metastasis of the lymph node using contrast enhanced ultrasonography with Sonazoid. Between December 2013 and May 2014, 32 patients with operable breast cancer were enrolled in this study. We evaluated the detection of axillary sentinel lymph nodes and the evaluation of axillary lymph nodes metastasis using contrast enhanced computed tomography, color Doppler ultrasonography and contrast enhanced ultrasonography with Sonazoid. All the sentinel lymph nodes were identified, and the sentinel lymph nodes detected by contrast enhanced ultrasonography with Sonazoid corresponded with those detected by computed tomography lymphography and indigo carmine method. The detection of metastasis based on contrast enhanced computed tomography were sensitivity 20.0 %, specificity 88.2 %, PPV 60.0 %, NPV 55.6 %, accuracy 56.3 %. Based on color Doppler ultrasonography, the results were sensitivity 36.4 %, specificity 95.2 %, PPV 80.0 %, NPV 74.1 %, accuracy 75.0 %. Based on contrast enhanced ultrasonography with Sonazoid, the results were sensitivity 81.8 %, specificity 95.2 %, PPV 90.0 %, NPV 90.9 %, accuracy 90.6 %. The results suggested that contrast enhanced ultrasonography with Sonazoid was the most accurate among the evaluations of these modalities. In the future, we believe that our method would take the place of conventional sentinel lymph node biopsy for an axillary staging method.

Sentinel Lymph Node Detection Using Carbon Nanoparticles in Patients with Early Breast Cancer

PURPOSE

Carbon nanoparticles have a strong affinity for the lymphatic system. The purpose of this study was to evaluate the feasibility of sentinel lymph node biopsy using carbon nanoparticles in early breast cancer and to optimize the application procedure.

METHODS

Firstly, we performed a pilot study to demonstrate the optimized condition using carbon nanoparticles for sentinel lymph nodes (SLNs) detection by investigating 36 clinically node negative breast cancer patients. In subsequent prospective study, 83 patients with clinically node negative breast cancer were included to evaluate SLNs using carbon nanoparticles. Another 83 SLNs were detected by using blue dye. SLNs detection parameters were compared between the methods. All patients irrespective of the SLNs status underwent axillary lymph node dissection for verification of axillary node status after the SLN biopsy.

RESULTS

In pilot study, a 1 ml carbon nanoparticles suspension used 10-15min before surgery was associated with the best detection rate. In subsequent prospective study, with carbon nanoparticles, the identification rate, accuracy, false negative rate was 100%, 96.4%, 11.1%, respectively. The identification rate and accuracy were 88% and 95.5% with 15.8% of false negative rate using blue dye technique. The use of carbon nanoparticles suspension showed significantly superior results in identification rate (p = 0.001) and reduced false-negative results compared with blue dye technique.

CONCLUSION

Our study demonstrated feasibility and accuracy of using carbon nanoparticles for SLNs mapping in breast cancer patients. Carbon nanoparticles are useful in SLNs detection in institutions without access to radioisotope.

Improved false negative rate of axillary status using sentinel lymph node biopsy and ultrasound-suspicious lymph node sampling in patients with early breast cancer

Background

The false negative rate of sentinel lymph node biopsy (SLNB) is 5-10%, and results in improper patient management. The study was to assess the value of ultrasound-suspicious axillary lymph node biopsy (USALNB) in patients with early breast cancer, and to compare SLNB combined with USALNB (SLNB + USALNB) with SLNB alone.

Methods

From January 2010 to July 2013, 216 patients with early breast cancer were enrolled consecutively at the Department of Breast and Thyroid Surgery, Qianfoshan Hospital, Shandong University. All patients underwent wire localization of the suspicious node by color Doppler ultrasonography, followed by SLNB 2–3 hours later, suspicious node lymphadenectomy, and level ≥ II axillary dissection (as the gold standard). The predictive values of node status between SLNB + USALNB and SLNB alone were compared.

Results

The success rate of SLNB was 99.1% (214/216). After axillary dissection, 71 patients were confirmed with axillary lymph node metastases by pathological examinations. Eight false negatives were observed using SLNB alone, resulting in sensitivity of 88.7%, specificity of 100%, false negative rate of 11.3%, and false positive rate of 0% in predicting the axillary node status. SLNB + USALNB resulted in sensitivity of 97.2%, specificity of 100%, false negative rate of 2.8%, and false positive rate of 0%. The false negative rate of SLNB + USALNB was significantly different from that of SLNB alone (P = 0.031).

Conclusions

SLNB + USALNB seems to be a low-risk procedure that might be useful in reducing the false negative rate of SLNB, improving the accuracy of axillary nodes evaluation in early breast cancer.

[Relevance of the sentinel lymph node biopsy in breast multifocal and multicentric cancer]

OBJECTIVES

The sentinel lymph node biopsy is a gold standard in the management of breast cancer. Its role in multifocal or multicentric tumors is still evolving. The aim of this study is to assess the feasibility and pertinence of sentinel lymph node biopsy in multifocal and multicentric tumors based on a systematic review of literature.

METHODS

A systematic review was conducted searching in the following electronic databases PubMed using "sentinel lymph node biopsy", "breast cancer", "multifocal tumor", "multicentric tumor" and "multiple tumor" as keywords. We included original articles published between 2000 and 2014, both French and English, studying feasibility of sentinel lymph node biopsy in invasive breast cancer, multicentric and/or multifocal tumors. The first end point was success rate and false negative rate.

RESULTS

Twenty-six articles were included in this literature review, with 2212 cases (782 multifocal, 737 multicentric and 693 multiple tumors). Percentage of tumors whose stage was higher than stage T2 ranged from 0 to 86.3%. Success rate average was 83.1%. False negative average was 8.2%. False negative rate was less than 10% in 15 articles. Mean of sentinel lymph node biopsy was 2 (1-9). The average rate of sentinel lymph node positive was 50.6%. Axillary recurrence rate was 0.5%.

CONCLUSION

Despite the methodological biases of the studies included in this review of literature, the false negative rate of sentinel node biopsy in multifocal and multicentric breast cancers are less than 10% with a low rate of axillary recurrence. Despite the lack of randomized study, this procedure can be routinely performed in accordance with rigorous technical process.

Optimising magnetic sentinel lymph node biopsy in an in vivo porcine model

The magnetic technique for sentinel lymph node biopsy (SLNB) has been evaluated in several clinical trials. An in vivo porcine model was developed to optimise the magnetic technique by evaluating the effect of differing volume, concentration and time of injection of magnetic tracer. A total of 60 sentinel node procedures were undertaken. There was a significant correlation between magnetometer counts and iron content of excised sentinel lymph nodes (SLNs) (r=0.82; P<0.001). Total number of SLNs increased with increasing volumes of magnetic tracer (P<0.001). Transcutaneous magnetometer counts increased with increasing time from injection of magnetic tracer (P<0.0001), plateauing within 60min. Increasing concentration resulted in higher iron content of SLNs (P=0.006). Increasing magnetic tracer volume and injecting prior to surgery improve transcutaneous 'hotspot' identification but very high volumes, increase the number of nodes excised.

FROM THE CLINICAL EDITOR

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging of breast cancer patients. Although the current gold standard technique is the combined injection of technetium-labelled nanocolloid and blue dye into the breast, the magnetic technique, using superparamagnetic carboxydextran-coated iron oxide (SPIO), has also been demonstrated as a feasible alternative. In this article, the authors set up to study factors in order to optimize the magnetic tracers.

99mTc-dextran lymphoscintigraphy can detect sentinel lymph node in breast cancer patients

The aim of this study was to retrospectively determine the accuracy and feasibility of using ^99mTc-dextran (DX) lymphoscintigraphy for the localization of sentinel lymph nodes (SLNs) in breast cancer patients. The relevant factors affecting lymphoscintigraphy were also investigated. In this study, 235 breast cancer patients underwent ^99mTc-DX lymphoscintigraphic imaging and examination by a γ-probe method in combination with blue dye staining to detect SLNs. The detection results were considered in combination with rapid frozen pathology results to determine whether SLN metastasis was positive or negative. SLNs were identified in 191 patients by γ-probe detection among the 202 patients that tested positive by lymphoscintigraphic imaging, a coincidence rate of 94.6%. This suggested that lymph node metastasis had occurred and could be detected using lymphoscintigraphy. The axillary status of the breast cancer patients was also predicted using lymphoscintigraphy and the false-negative rate, sensitivity, specificity and positive predictive value were 13.3% (4/30), 90.7% (39/43), 23.4% (45/192) and 13.5% (21/155), respectively. The age of the patient, menstrual status, tumor location, tumor size, pathological type, preoperative biopsy and neoadjuvant chemotherapy were unrelated to the success of lymphoscintigraphy (P>0.05). ^99mTc-DX lymphoscintigraphy is able to exactly determine the location of SLN in breast cancer patients, and can be used for guiding γ-probe methods and sentinel lymph node biopsy.

Axillary lymph node recurrence after sentinel lymph node biopsy performed using a combination of indocyanine green fluorescence and the blue dye method in early breast cancer

BACKGROUND

There is limited information on indocyanine green (ICG) fluorescence and blue dye for detecting sentinel lymph node (SLN) in early breast cancer. A retrospective study was conducted to assess the feasibility of an SLN biopsy using the combination of ICG fluorescence and the blue dye method.

METHODS

Seven hundred and fourteen patients with clinically node-negative breast cancer were included in this study. They underwent SLN biopsy using a combination of ICG fluorescence and the blue dye method from March 2007 to February 2014. The ICG (a fluorescence-emitting source) and patent blue (the blue dye) were injected into the patients' subareolar region. The removed lymph nodes that had ICG fluorescence and/or blue dye uptake were defined as SLNs. The results of the SLN biopsies and follow-up results of patients who underwent SLN biopsy alone were investigated.

RESULTS

In 711 out of 714 patients, SLNs were identified by a combination of ICG fluorescence and the blue dye method (detection rate, 99.6 %). The average number of SLNs was 2.4 (range 1-7), and the average number of resected swollen para-SLNs was 0.4 (range 0-5). Ninety-nine patients with an SLN and/or para-SLN involvement during the intraoperative pathological diagnosis underwent axillary lymph node resection (ALND). In addition, two of three patients whose SLN was not identified also underwent ALND. In 46 of 101 patients with an ALND, non-SLN involvement was not found. Follow-up results were analyzed in 464 patients with invasive carcinoma excluding those with ductal carcinoma in situ (n = 148) and those who underwent ALND (n = 101). During the follow-up period (range 4.4-87.7 months; median, 38 months), two patients (0.4 %) developed axillary lymph node recurrence. They were successfully salvaged, and to date, no further locoregional recurrence has been observed.

CONCLUSIONS

A high rate of SLN detection and low rate of axillary lymph node recurrence were confirmed by an SLN biopsy using a combination of ICG fluorescence and the blue dye method. Therefore, it is suggested that this method may replace the combination of dye and radioisotope methods.

Clinical significance of the axillary arch in sentinel lymph node biopsy

Purpose

The axillary arch is an anomalous muscle that is not infrequently encountered during axillary sentinel lymph node biopsy (SLNB) of breast cancer patients. In this study, we aimed to investigate how often the axillary arch is found during SLNB and whether it affects the intraoperative sentinel lymph node (SLN) identification rate.

Methods

We retrospectively analyzed the correlation between the presence of the axillary arch and the SLN sampling failure rate during SLNB in 1,069 patients who underwent axillary SLNB for invasive breast cancer.

Results

Of 1,069 patients who underwent SLNB, 79 patients (7.4%) had the axillary arch present. The SLNB failure rate was high when the patient's body mass index was ≥25 (p=0.026), when a single SLN mapping technique was used (p=0.012), and when the axillary arch was present (p<0.001). These three factors were also found to be statistically significant by multivariate analysis, and of these three factors, presence of the axillary arch most significantly increased the SLNB failure rate (hazard ratio, 10.96; 95% confidence interval, 4.42-27.21; p<0.001). Additionally, if the axillary arch was present, the mean operative time of SLNB was 20.8 minutes, compared to 12.5 minutes when the axillary arch was not present (p<0.001). If the axillary arch was present, the SLN was often located in a high axillary region (67%) rather than in a general low axillary location.

Conclusion

The axillary arch was found to be a significant factor affecting intraoperative SLN failure rate. It is necessary to keep in mind that carefully checking the high axillar region during SLNB in breast cancer patients with the axillary arch is important for reducing SLN sampling failure.

Novel techniques for sentinel lymph node biopsy in breast cancer: a systematic review

The existing standard for axillary lymph node staging in breast cancer patients with a clinically and radiologically normal axilla is sentinel lymph node biopsy with a radioisotope and blue dye (dual technique). The dependence on radioisotopes means that uptake of the procedure is limited to only about 60% of eligible patients in developed countries and is negligible elsewhere. We did a systematic review to assess three techniques for sentinel lymph node biopsy that are not radioisotope dependent or that refine the existing method: indocyanine green fluorescence, contrast-enhanced ultrasound using microbubbles, and superparamagnetic iron oxide nanoparticles. Our systematic review suggested that these new methods for sentinel lymph node biopsy have clinical potential but give high levels of false-negative results. We could not identify any technique that challenged the existing standard procedure. Further assessment of these techniques against the standard dual technique in randomised trials is needed.

Rate of sentinel lymph node identification using isosulfan blue dye in breast cancer patients at Charoenkrung Pracharak Hospital, Thailand

Background: The sentinel lymph node (SLN) is the first lymph node to receive lymphatic drainage from a primary breast tumor. If the SLN contains no metastatic tumor, then it is unlikely other lymph nodes will contain breast cancer metastasis. When the SLN does contains metastasis, an axillary lymph node dissection (ALND) is recommended to further stage the axilla and to maintain locoregional control. SLNs can be identified by using a dye, radioisotope, or combined techniques.

Objective: To determine the rate of SLN identification using isosulfan blue dye in breast cancer patients at Charoenkrung Pracharak Hospital, Thailand, and factors that affect it.

Methods: This prospective study of 106 consecutive cases breast cancer enrolled 105 women (1 bilateral breast cancer case) between October 2011 and October 2013 at Charoenkrung Pracharak Hospital. Clinical and pathological features were analyzed for the effectiveness of SLN identification using isosulfan blue dye.

Results: The rate of SLN identification using isosulfan blue dye in breast cancer patients at Charoenkrung Pracharak Hospital was 92%. The method was safe and well tolerated in early-stage breast cancer patients.

Conclusion: The effectiveness of sentinel node identification using isosulfan blue dye in breast cancer patients at Charoenkrung Pracharak Hospital is consistent with that shown in studies from other countries.

Mapping lymph nodes in cancer management - role of (99m)Tc-tilmanocept injection

Two decades ago, lymphatic mapping of sentinel lymph nodes (SLN) was introduced into surgical cancer management and was termed sentinel node navigated surgery. Although this technique is now routinely performed in the management of breast cancer and malignant melanoma, it is still under investigation for use in other cancers. The radioisotope technetium (^99mTc) and vital blue dyes are among the most widely used enhancers for SLN mapping, although near-infrared fluorescence imaging of indocyanine green is also becoming more commonly used. ^99mTc-tilmanocept is a new synthetic radioisotope with a relatively small molecular size that was specifically developed for lymphatic mapping. Because of its small size, ^99mTc-tilmanocept quickly migrates from its site of injection and rapidly accumulates in the SLN. The mannose moieties of ^99mTc-tilmanosept facilitate its binding to mannose receptors (CD206) expressed in reticuloendothelial cells of the SLN. This binding prevents transit to second-echelon lymph nodes. In Phase III trials of breast cancer and malignant melanoma, and Phase II trials of other malignancies, ^99mTc-tilmanocept had superior identification rates and sensitivity compared with blue dye. Trials comparing ^99mTc-tilmanocept with other ^99mTc-based agents are required before it can be routinely used in clinical settings.

It is not always necessary to do axillary dissection for T1 and T2 breast cancer--point

Axillary lymph node dissection (ALND) has been a part of breast cancer management since the 1900s. The idea that axillary metastases do not require surgical removal is a repudiation of the Halstedian concept of breast cancer biology, yet multiple prospective randomized studies show that the incidence of nodal recurrence in patients not having ALND is substantially lower than expected, based on the incidence of axillary metastases in patients having ALND, and survival does not differ based on axillary treatment. Avoidance of axillary dissection significantly reduces the morbidity of breast cancer surgery. As the use of systemic therapy has increased and targeted therapies have become available, the incidence of axillary recurrence in patients not having dissection has decreased to approximately 1% at 5 years, making routine axillary dissection difficult to justify. ALND is no longer standard management for patients with T1 and T2, clinically node-negative cancers undergoing breast-conserving therapy and found to have a positive sentinel node, and can also be avoided in patients with these tumor features having mastectomy if the need for postmastectomy radiotherapy is clear with the finding of a positive sentinel node.

A Cost-Utility Analysis Comparing Standard Axillary Lymph Node Dissection with Sentinel Lymph Node Biopsy in Patients with Early Stage Breast Cancer in Thailand

OBJECTIVES

In Thailand, axillary lymph node dissection (ALND) is the dominant form of treatment for breast cancer, even though the treatment often leaves patients with some degree of arm morbidity. Sentinel lymph node biopsy (SNB) is widely accepted globally as a preferable alternative procedure because of its lower rates of associated morbidity. This study compared the cost-utility of SNB and ALND in patients with early stage breast cancer in Thailand.

METHODS

A decision tree with a 5-year time horizon was developed. Outcomes that were relevant to SNB and ALND were included, along with locoregional recurrence of cancer and lymphedema scenarios. The model parameters were derived from a meta-analysis of international clinical trials and other relevant literature. The resources and cost data were derived from the medical records of tertiary hospitals. Health utilities were measured by using the standard gamble technique. A sensitivity analysis was performed using a set of plausible parameters.

RESULTS

The incremental cost-effectiveness ratio (ICER) in the base-case analysis showed that SNB was more cost-effective than ALND. ICERs were -275,140 and -470,600 Thailand baht/quality-adjusted life-year gained from the provider perspective and the societal perspective, respectively. The most sensitive parameter was the utility score of patients with early stage breast cancer who had received breast-conserving therapy with lymphedema; the sensitivity and specificity of SNB had no impact on the ICER.

CONCLUSIONS

The study confirmed that SNB was an economically viable alternative treatment to ALND. In developing countries, where resources are limited, nationwide implementation of SNB warrants widespread support from relevant stakeholders, including medical personnel and policymakers.

Sentinel Lymph Node Biopsy for Patients With Early-Stage Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update

Purpose

To provide evidence-based recommendations to practicing oncologists, surgeons, and radiation therapy clinicians to update the 2005 clinical practice guideline on the use of sentinel node biopsy (SNB) for patients with early-stage breast cancer.

Methods

The American Society of Clinical Oncology convened an Update Committee of experts in medical oncology, pathology, radiation oncology, surgical oncology, guideline implementation, and advocacy. A systematic review of the literature was conducted from February 2004 to January 2013 in Medline. Guideline recommendations were based on the review of the evidence by Update Committee.

Results

This guideline update reflects changes in practice since the 2005 guideline. Nine randomized clinical trials (RCTs) met systematic review criteria for clinical questions 1 and 2; 13 cohort studies informed clinical question 3.

Recommendations

Women without sentinel lymph node (SLN) metastases should not receive axillary lymph node dissection (ALND). Women with one to two metastatic SLNs planning to undergo breast-conserving surgery with whole-breast radiotherapy should not undergo ALND (in most cases). Women with SLN metastases who will undergo mastectomy should be offered ALND. These three recommendation are based on RCTs. Women with operable breast cancer and multicentric tumors, with ductal carcinoma in situ (DCIS) who will undergo mastectomy, who previously underwent breast and/or axillary surgery, or who received preoperative/neoadjuvant systemic therapy may be offered SNB. Women who have large or locally advanced invasive breast cancer (tumor size T3/T4), inflammatory breast cancer, or DCIS (when breast-conserving surgery is planned) or are pregnant should not undergo SNB. These recommendations are based on cohort studies and/or informal consensus. In some cases, updated evidence was insufficient to update previous recommendations.

Nodal status assessment in breast cancer: strategies of clinical grounds and quality of life implications

Even in the era of gene-expression profiling, the nodal status still remains the primary prognostic discriminant in breast cancer patients. The exclusion of node involvement using noninvasive methods could reduce the rate of axillary surgery, thereby preventing from suffering complications. However, lymphatic mapping with sentinel node biopsy (SNB) is one of the most interesting recent developments in surgical oncology. Optimization of procedure could be implemented by dual mapping injection site skills, resection of all hot or blue nodes through tracer combination, and improvement in atypical drainage patterns mapping. This anatomical analysis suggests safety measures in patients with high probability of node metastasis through a renewed interest in surgical management. The perspective of a guided axillary sampling (GAS) could represent a potential development of recent anatomical and functional acquisitions, offering a dynamic technique shared according to clinical and anatomical disease parameters. Furthermore, the surgical staging procedures may adopt a conservative approach through the evaluation of upper arm lymphatics, thus defining a functional model aimed at the reduction of short- and long-term adverse events. Quality results in breast cancer surgery need to generate oncological safety devoid of complications through renewed clinical experience.

Blue dye is sufficient for sentinel lymph node biopsy in breast cancer

BACKGROUND

Most previous studies have reported superior results when blue dye and radiocolloids were used together for sentinel lymph node (SLN) biopsy in early breast cancer. Blue dye was reported to perform poorly when used alone, although more recent studies have found otherwise. This study reviewed the authors' practice of performing SLN biopsy with blue dye alone.

METHODS

This was a retrospective review of patients who underwent SLN biopsy using blue dye alone from 2001 to 2005, when SLN biopsy was performed selectively and always followed by axillary lymph node dissection (ALND), and from 2006 to 2010, when SLN biopsy was offered to all suitable patients and ALND done only when the SLN was not identified or positive for metastasis.

RESULTS

Between 2001 and 2005, 170 patients underwent SLN biopsy with blue dye alone. The overall SLN non-identification rate was 8·4 per cent. The overall false-negative rate was 34 per cent, but decreased with each subsequent year to 13 per cent in 2005. From 2006 to 2010, 610 patients underwent SLN biopsy with blue dye alone. The SLN was not identified in 12 patients (2·0 per cent) and no significant contributing factor was identified. A median of 2 (range 1-11) SLNs were identified. A non-SLN was found to be positive for metastasis in two patients with negative SLNs. Axillary nodal recurrence developed in one patient; none developed internal mammary nodal recurrence. Anaphylaxis occurred in one patient.

CONCLUSION

Blue dye performed well as a single modality for SLN biopsy. Non-identification, axillary nodal recurrence and serious allergic reactions were uncommon.

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).

Near-infrared fluorescence sentinel lymph node mapping in breast cancer: a multicenter experience

Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has the potential to improve the sentinel lymph node (SLN) procedure by facilitating percutaneous and intraoperative identification of lymphatic channels and SLNs. Previous studies suggested that a dose of 0.62 mg (1.6 mL of 0.5 mM) ICG is optimal for SLN mapping in breast cancer. The aim of this study was to evaluate the diagnostic accuracy of NIR fluorescence for SLN mapping in breast cancer patients when used in conjunction with conventional techniques. Study subjects were 95 breast cancer patients planning to undergo SLN procedure at either the Dana-Farber/Harvard Cancer Center (Boston, MA, USA) or the Leiden University Medical Center (Leiden, the Netherlands) between July 2010 and January 2013. Subjects underwent the standard-of-care SLN procedure at each institution using (99)Technetium-colloid in all subjects and patent blue in 27 (28 %) of the subjects. NIR fluorescence-guided SLN detection was performed using the Mini-FLARE imaging system. SLN identification was successful in 94 of 95 subjects (99 %) using NIR fluorescence imaging or a combination of both NIR fluorescence imaging and radioactive guidance. In 2 of 95 subjects, radioactive guidance was necessary for initial in vivo identification of SLNs. In 1 of 95 subjects, NIR fluorescence was necessary for initial in vivo identification of SLNs. A total of 177 SLNs (mean 1.9, range 1-5) were resected: 100 % NIR fluorescent, 88 % radioactive, and 78 % (of 40 nodes) blue. In 2 of 95 subjects (2.1 %), SLNs-containing macrometastases were found only by NIR fluorescence, and in one patient this led to upstaging to N1. This study demonstrates the safe and accurate application of NIR fluorescence imaging for the identification of SLNs in breast cancer patients, but calls into question what technique should be used as the gold standard in future studies.

Sentinel node biopsy using a magnetic tracer versus standard technique: the SentiMAG Multicentre Trial

BACKGROUND

The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate).

METHODS

A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye).

RESULTS

A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.

CONCLUSIONS

The magnetic technique is a feasible technique for SLNB, with an identification rate that is not inferior to the standard technique.