Guidelines for sentinel node biopsy and lymphatic mapping of patients with breast cancer

Lymphoscintigraphy and Single-Photon Emission Computed Tomography (SPECT)/CT to Determine Need for Second Sentinel Lymph Node Biopsy for Breast Cancer Recurrence Following Ipsilateral Breast/Axillary Surgery

BACKGROUND For patients with cN0 breast cancer, sentinel node biopsy (SNB) is performed to confirm metastasis. When cancer recurs after a breast/axillary surgery, performing a second SNB is debatable in terms of its accuracy and significance. However, SNB is often performed because it is less invasive and can provide significant information. This report describes our experience of performing lymphoscintigraphy and single-photon emission computed tomography (SPECT)/CT to determine whether SNB is informative or not in patients who develop ipsilateral breast tumor recurrence (IBTR) following a breast/axillary surgery. CASE REPORT We included 9 patients with breast cancer and a history of ipsilateral breast/axillary surgery who underwent lymphoscintigraphy and SPECT/CT between April 2020 and July 2023. For lymphoscintigraphy, 20-25 MBq of 99mTc-phytate was injected subcutaneously in the areola, and planar images and SPECT/CT were taken at 15 min and 3 h after the injection. In lymphoscintigraphy, radioisotope accumulation was detected in 2 patients at 15 min and 8 patients at 3 h; it was not detected in 1 patient. The accumulation site was only the axilla in 3 patients; other sites including the axilla in 3, and sites outside the axilla in 2. CONCLUSIONS When a patient who previously underwent breast/axillary surgery develops IBTR, the initial surgery may have altered the lymphatic flow. The lymphatic flow varied between the contralateral or ipsilateral internal mammary lymph nodes, contralateral axilla, multidirectional flow, and the axilla alone. Lymphoscintigraphy and SPECT/CT may be useful for early determination of the need for another SNB.

Is Sentinel Lymph Node Biopsy Necessary in Patients who Undergo Prophylactic Mastectomy?

BACKGROUND

Over the last decade, rates of risk-reducing prophylactic mastectomy (PM) have risen dramatically. A topic of debate regarding the procedure is whether to use sentinel lymph node biopsy (SLNB) at the time of PM and what factors might predict for such need. In order to assess the rate of identifying presence of occult invasive breast cancer in the PM specimen, we performed a retrospective review of the pathology findings from a single-surgeon case-series of PM.

METHODS

Patients undergoing PM between January 2013 and June 2019 at Orlando Health Cancer Institute were identified for a retrospective chart review. Demographic, clinical, and histopathological data from the surgical procedure were collected and analyzed for the incidence of occult invasive breast cancer in the PM specimen.

RESULTS

A total of 146 consecutive patients with PM were identified; 120 (82.2%) underwent contralateral PM (CPM) and 26 (17.8%) underwent bilateral PM (BPM). Final pathology of the 172 PM specimens identified 4 (3.3%) with lobular carcinoma in situ, 3 (2.5%) with atypical ductal hyperplasia, and 2 (1.7%) with atypical lobular hyperplasia and 2 (1.7%) with intraductal papilloma. No invasive malignancy was detected in any of the 172 PM specimens.

CONCLUSIONS

The absence of occult invasive carcinoma in 172 consecutive PM specimens suggests a limited clinical utility in routinely performing SLNB in this setting. This study also suggests that use of preoperative breast MRI imaging could offer a potential non-invasive tool to detect occult malignancy and select patients who can safely undergo omission of SLNB at the time of PM.

Long-term results of fluorescence and indigo carmine blue dye-navigated sentinel lymph node biopsy

BACKGROUND

Sentinel lymph node biopsy is widely applied for the management of clinically node-negative breast cancer, and a radioisotope with a blue dye are most often used as tracers. Fluorescence of indocyanine green could also potentially be used as tracer. This study aimed to demonstrate the long-term survival results of fluorescence-guided sentinel lymph node biopsy.

PATIENTS AND METHODS

Patients with clinically node-negative breast cancer who underwent surgery as initial treatment were included in this study. Both fluorescence of indocyanine green and indigo carmine blue dye were used as tracers. Axillary lymph node dissection was omitted unless metastasis was pathologically proven in sentinel nodes. Breast cancer recurrence and death were recorded and prognostic factors were identified using disease-free survival and overall survival data.

RESULTS

A total of 565 patients were analyzed. There were 14 (2.5%) patients whose sentinel nodes could not be identified, yielding an identification rate of 97.5%. Axillary dissection was performed in 90 patients. Forty-three recurrences including 6 ipsilateral axilla recurrence and 13 deaths were observed during the median 83 months of follow-up period. Seven-year disease-free and overall survival were 92.4% and 97.3%, respectively. Multivariate analyses demonstrated that pre-menopausal status and invasive lobular carcinoma were significant unfavorable prognostic factors of disease-free survival. Half of ipsilateral axilla recurrences occurred within 5 years after surgery and these recurrences were correlated with inappropriate adjuvant therapy.

CONCLUSION

Fluorescence-guided sentinel lymph node biopsy demonstrated favorable prognostic results and could be alternative to the radioisotope for clinically node-negative breast cancer.

Preoperative tumor biopsy results in more detected sentinel nodes than intraoperative biopsy in breast cancer patients

Background

Sentinel lymph node biopsy (SLNB) plays a vital role in breast cancer surgery, and the identified number of sentinel nodes determines its accuracy for representing the status of the axillae. There are two types of tumor biopsies in breast cancer: preoperative and intraoperative biopsies. We compared the effects of the two different biopsies on the results of SLNB.

Methods

Patients with clinical stages T1–3, N0 (cT1-3 N0) tumors were enrolled in this study. A total of 53% of patients received preoperative tumor biopsy, and 47% received intraoperative excisional biopsy. To identify the sentinel lymph nodes, patients received dual tracer injection. The number of SLNs detected and the false-negative rate were compared between groups.

Results

A total of 204 patients were enrolled, 108 received preoperative tumor biopsy, and 96 received intraoperative excisional biopsy. Among all the patients, 160 received axillary lymph node dissection (ALND) following SLNB. Preoperative tumor biopsy detected more SLNs than intraoperative biopsy (mean rank 113.87 vs. 90.9, p = 0.004). The false-negative rates in the preoperative and intraoperative tumor biopsy groups were 3% and 18%, respectively.

Conclusions

Patients in the preoperative tumor biopsy group had more SLNs identified than intraoperative biopsy patients. The false-negative rate was also lower in the preoperative biopsy group.

Hybrid (2D/3D) Dosimetry of Radiolabeled Gold Nanoparticles for Sentinel Lymph Node Detection in Patients with Breast Cancer

Previously, we reported the preparation and preclinical studies of ^99mTc-labeled gold nanoparticles-mannose (^99mTc-AuNP-mannose) with potential for sentinel lymph node (SLN) detection by using nuclear medicine procedures. This study aimed to evaluate the biokinetics and hybrid (2D/3D) dosimetry of ^99mTc-AuNP-mannose in five patients with breast cancer under a sentinel lymph node detection protocol. Anterior and posterior whole-body planar images (2D, at 0.5, 2, 6, and 24 h) and single-photon emission computed tomography (3D at 6.5 h)/computed tomography (SPECT/CT) images were acquired after ^99mTc-AuNP-mannose administration (37 MBq). Through a hybrid quantification method, activity in tissues of interest at the different acquisition times was determined and integrated over time to obtain the total nuclear transformations (N), as well as the mean residence time, in each tissue. N values and the OLINDA code were used for estimating the internal radiation absorbed doses. Results demonstrated that ^99mTc-AuNP-mannose successfully accumulates and remains up to 24 h in the sentinel lymph node without detectable migration to other lymph nodes and no side effects on patients. Negligible absorption of the radiolabeled nanoparticles into the circulatory system was observed, from which the radio-nanosystem is rapidly eliminated by kidneys. Hybrid (2D/3D) dosimetry evaluations showed equivalent doses to SLN, breast, and kidneys of 172.34, 5.32, and 0.08 mSv/37 MBq, respectively, with an effective dose of 2.05E - 03 mSv/MBq. The mean effective residence time in SLN was 0.92 h. This preliminary study indicates that the use of ^99mTc-AuNP-mannose for successful SLN detection in patients is safe, producing an effective dose at the level recommended for diagnostic studies (<10 mSv).

Indocyanine green fluorescence method for sentinel lymph node biopsy in breast cancer

BACKGROUND/OBJECTIVE

Breast biopsy and analysis of sentinel lymph nodes (SLNs) accurately predict tumor status in the affected basin and help in avoiding unnecessary axillary lymph node dissection, which is associated with remarkable morbidity risk. Blue dye and radioisotope are the most widely used mapping agents, but non-radioactive tracers of comparable accuracy warrant further investigation. This study aimed to investigate utilization of indocyanine green (ICG) fluorescence in sentinel node localization compared with blue dye and to assess the incremental value of ICG.

METHODS

A total of 39 consecutive patients underwent sentinel lymph node biopsy (SLNB) (40 cases: 38 unilateral and 1 bilateral) with combined blue dye and ICG for localization. The obtained fluorescence images of the lymphatic system were investigated.

RESULTS

All 84 lymph nodes removed in 40 procedures were identified by ICG, but only 37 were identified by blue dye. The ICG method identified an average of 2.1 SLNs in 39 of 40 cases with a detection rate of 97.5%, but only 0.93 SLN per case with blue dye. Subcutaneous lymphatic channel patterns were also detected by fluorescent imaging in 37 procedures, which all revealed lymphatic drainage toward the axilla except in one case with internal mammary pathway.

CONCLUSION

This study demonstrated the accuracy and safety of ICG for SLNB and its superiority to blue dye method in SLN localization. Therefore, ICG fluorescence method is safe and effective addition in breast clinical settings, wherein blue dye alone is used.

Detection of Nonpalpable Tiny Axillary Lymph Nodes Surrounded by Adipose Tissue Using a Near-Infrared Camera

Background: It is not always possible to detect nonpalpable small lymph nodes (LNs) surrounded by adipose tissue under the wavelength of visible light. A newly developed near-infrared camera with InGaAs element was able to capture photographs using light at >1000-nm wavelength, at which the difference in absorbance between water and lipids is large. This study investigated the ability to detect nonvisible small LNs using light at 1300-nm wavelength. Methods and Results: Following retrieval of LNs through axillary LN dissection from 20 patients with breast cancer, residual specimens were simultaneously photographed using light at 970-, 1070-, 1200-, 1300-, 1450-, and 1600-nm wavelengths. A total of 45 specimens were observed pathologically at the selected portions in which the 1300-nm light was absorbed (high absorbance group [HA group], n = 25) and those in which the 970-nm light was absorbed instead (low absorbance group [LA group], n = 20). All specimens categorized in the HA group detected the LNs, whereas none of those categorized in the LA group detected an LN. The sensitivity and specificity in the identification of an LN were 1.0. The LNs detected using this camera were significantly smaller than those detected by surgeons (3.00 ± 2.93 mm vs. 5.90 ± 3.91 mm, p < 0.01). Discussion: The light at 1300-nm wavelength was absorbed by axillary LNs. This camera detected LNs that were undetectable by surgeons. This novel technology may be applied to lymphatic microsurgery and contribute to the development of a minimally invasive LN dissection method.

Optical and Optoacoustic Imaging

The present chapter summarizes progress with optical methods that go beyond human vision. The focus is on two particular technologies: fluorescence molecular imaging and optoacoustic (photoacoustic) imaging. The rationale for the selection of these two methods is that in contrast to optical microscopy techniques, both fluorescence and optoacoustic imaging can achieve large fields of view, i.e., spanning several centimeters in two or three dimensions. Such fields of views relate better to human vision and can visualize large parts of tissue, a necessary premise for clinical detection. Conversely, optical microscopy methods only scan millimeter-sized dimensions or smaller. With such operational capacity, optical microscopy methods need to be guided by another visualization technique in order to scan a very specific area in tissue and typically only provide superficial measurements, i.e., information from depths that are of the order of 0.05-1 mm. This practice has generally limited their clinical applicability to some niche applications, such as optical coherence tomography of the retina. On the other hand, fluorescence molecular imaging and optoacoustic imaging emerge as more global optical imaging methods with wide applications in surgery, endoscopy, and non-invasive clinical imaging, as summarized in the following. The current progress in this field is based on a volume of recent review and other literature that highlights key advances achieved in technology and biomedical applications. Context and figures from references from the authors of this chapter have been used here, as it reflects our general view of the current status of the field.

Ultrasound assessment of translation of microbubbles driven by acoustic radiation force in a channel filled with stationary fluid

In this report, a method is proposed to quantify the translation of ultrasound contrast agent (UCA) microbubbles driven by acoustic radiation for the detection of channels filled with stationary fluid. The authors subjected UCA microbubbles in a channel with diameters of 0.1 and 0.5 mm to ultrasound pulses with a center frequency of 14.4 MHz. The translational velocity of the UCA microbubbles increased with the sound pressure and pulse repetition frequency (PRF) of the transmitted ultrasound. The mean translational velocity reached 0.75 mm/s at a negative peak sound pressure of 2.76 MPa and a PRF of 2 kHz. This trend agreed with the theoretical prediction, which indicated that the translational velocity was proportional to the square of the sound pressure and the PRF. Furthermore, an experiment was carried out with a phantom that mimics tissue and found that the proposed method aided in detection of the channel, even in the case of a low contrast-echo to tissue-echo ratio. The authors expect to develop the proposed method into a technique for detecting lymph vessels.

Factors that affect the false negative rate of sentinel lymph node mapping with methylene blue dye alone in breast cancer

Objective

This study aimed to investigate the clinicopathological factors of the false negative rate (FNR) and accuracy of sentinel lymph node biopsy (SLNB) mapping with 1% methylene blue dye (MBD) alone, and to examine how to reduce the FNR in patients with breast cancer.

Methods

A total of 365 patients with invasive breast carcinoma who received axillary lymph node dissection after SLNB were retrospectively analyzed. SLNB was performed with 2 to 5 mL of 1% MBD. We studied the clinicopathological factors that could affect the FNR of SLNB.

Results

The identification rate of sentinel lymph nodes (SLNs) was 98.3% (359/365) and the FNR of SLNB was 10.4% (16/154). Multivariate analysis showed that the number of dissected SLNs and metastatic lymph nodes were independent predictive factors for the FNR of SLNB. The FNR in patients with 1, 2, 3, and ≥4 SLNs was 23.53%, 15.79%, 3.85%, and 1.79%, respectively.

Conclusions

SLNB mapping with MBD alone in patients with breast cancer can produce favorable identification rates. The FNR of SLNB decreases as the number of SLNs rises. Because of side effects of searching for additional SLNs and the FNR, removal of three or four SLNs may be appropriate.

Optimization of sentinel lymph node identification techniques in the Indian setting: A randomized clinical trial

INTRODUCTION

The recommended technique of sentinel lymph node biopsy (SLNB) in breast cancer is a combination of blue dye and radiotracer. In the Indian scenario, SLNB is still not routinely practiced due to lack of nuclear medicine facilities and unavailability of isosulfan blue or patent blue violet (PBV). This study was conducted for optimizing SLN identification techniques by comparing the identification rate using PBV and methylene blue (MB) in combination with radiotracer.

MATERIALS AND METHODS

Single-blinded two-arm parallel design randomized control trial was conducted at an apex teaching and research medical institute in India. Patients with axillary LN-negative breast cancer were included. Blue dye and radio tracer were injected preoperatively, and SLNB was performed using a combination technique. Frozen section was performed. Demographic, clinical, radiological, operative, and histopathological data were recorded. Descriptive statistics were used to represent patient characteristics. Baseline characteristics for entire cohort and between groups were compared using Student's t-test for quantitative variables and Chi-square test for qualitative variables.

RESULTS

A total of 119 patients were randomized for mapping with MB and 118 patients with PBV between 2011 and 2015. SLN was identified in 116 patients with MB and 115 with PBV. SLN identification proportions were 97.4% (MB) and 96.6% (PBV). In patients undergoing axillary lymph node dissection, concordance with SLNB was 98.5% and 96.61% in MB and PBV, respectively. False-negative proportion for MB was 2.56% and 7.69% for PBV, respectively. The cost of MB is about INR 15 per ~10-mL vial. The cost of PBV is approximately ~$91 per ampoule (equivalent to approximately INR 8190).

CONCLUSION

SLNB using MB can be recommended as the technique of choice in low-resource settings.

Sentinel Node Navigation in Gastric Cancer: Where Do We Stand?

BACKGROUND

Early gastric cancer (EGC) is more common nowadays and is related a to low percentage of lymph node metastasis. For this reason, there is enormous interest to implicate minimally invasive approaches. Recently, special efforts have been made towards a potential intraoperative (real-time) lymph node metastasis (LNM) assessment, as nodal disease status could not be identified with precision before or during surgery. In this direction, accurate prediction of the LNM status through sentinel LN mapping has been attempted, as an approach to the intraoperative detection of sentinel lymph nodes (SLNs). A careful literature search was conducted in order to clarify the potential clinical application of SN biopsy in the gastric cancer field.

CONCLUSION

The real clinical application of SN biopsy in gastric cancer treatment has been more than challenging due to the "complicated" nature of gastric lymphatic drainage and the high possibility of "skip" metastasis phenomenon. Notably, sophisticated technical aspects, such as the preferred tracer used and the potential "ideal" method to verify the presence of metastases in the resected SLNs, made SN biopsy application in gastric cancer field extremely demanding. Assessing the potential role of SN navigation for gastric cancer treatment in the era of advanced technology, where the minimally invasive surgical approaches are in the top of the scientific interest, it has to be highlighted that SN navigation for gastric cancer is a topic that remains highly controversial, and the need for future clinical trials on this topic is obvious.

Establishment of a model of sentinel lymph node metastasis using immunodeficient swine

Lymph node metastasis occurs via the migration of cancer cells through the lymphatic system. Sentinel lymph node (SLN) biopsy is a common diagnostic strategy. SLNs have been studied using healthy rodents and large animals without metastasis. Here we used immunodeficient swine to establish a model of lymph node metastasis. We used RAG2-knockout immunodeficient swine. A431 human epithelial carcinoma cells expressing green fluorescent protein were injected subcutaneously into the posterior sides of the auricle, forelimb and hindlimb of knockout swine. Indigo carmine dye was injected subcutaneously 8 weeks after tumour cell transplantation. SLNs were extracted, observed using a stereoscopic fluorescence microscope and analysed histologically using haematoxylin and eosin staining, and immunohistochemistry. Lymphoid follicles were found in wild-type swine, and a few aggregated lymphocytes and immature lymphoid follicles were observed in knockout swine. Fluorescence in the lymph nodes indicated metastasis of tumour cells to the lymph nodes. Tumour cells replaced lymph node architectures, showed high-grade nuclear atypia and formed irregular tumour nests. Our model may be useful for the preclinical validation of diagnostic methods and minimally invasive treatment of metastatic cancer.

Sentinel Lymph Node Evaluation: What the Radiologist Needs to Know

Axillary lymph node status is the single most important prognostic indicator in patients with breast cancer. Axillary lymph node dissection, the traditional method of staging breast cancer, is associated with significant morbidity. Sentinel lymph node biopsy has become standard in patients being treated for breast cancer with clinically negative lymph nodes. There is considerable variation in the medical literature regarding technical approaches to sentinel lymph node biopsy in patients with breast cancer. The purpose of this article is to describe our preferred approaches to sentinel lymph node biopsy with a review of the literature.

Assessment of hospital-level adjusted breast cancer sentinel lymph node positivity rates

BACKGROUND/OBJECTIVES

Proficiency of performing sentinel lymph node biopsy (SLNB) for breast cancer varies among hospitals and may be reflected in the hospital's SLNB positivity rate. Our objectives were to examine whether hospital characteristics are associated with variation in SLNB positivity rates and whether hospitals with lower-than-expected SLNB positivity rates have worse patient survival.

METHODS

Using the National Cancer Data Base, stage I to III breast cancer patients were identified (2004-2012). Hospital-level SLNB positivity rates were adjusted for tumor and patient factors. Hospitals were divided into terciles of SLNB positivity rates (lower-, higher-, as-expected). Hospital characteristics and survival were examined across terciles.

RESULTS

Of 438 610 SLNB patients (from 1357 hospitals), 78 104 had one or more positive SLN (21.3%). Hospitals in the low and high terciles were more likely to be low volume (low: RRR, 4.40; 95% CI, 2.89-6.57; P < 0.001; and high: RRR, 1.79; 95% CI, 1.21-2.64; P < 0.001) compared to hospitals with as-expected (middle tercile) SLNB positivity rates. Stage I patients at low- and high-tercile hospitals had statistically worse survival.

CONCLUSIONS

There is a wide variation in hospital SLNB positivity rates. Hospitals with lower- or higher-than-expected SLNB positivity rates were associated with survival differences. Hospital SLNB positivity rates may be a novel 'process measure' to report to hospitals for internal quality assessment.

Noninvasive detection of cancer spread to lymph nodes: A review of molecular imaging principles and protocols

Identification of cancer spread to tumor-draining lymph nodes offers critical information for guiding treatment in many cancer types. Current clinical methods of nodal staging are invasive and can have substantial negative side effects. Molecular imaging protocols have long been proposed as a less invasive means of nodal staging, having the potential to enable highly sensitive and specific evaluations. This review article summarizes the current status and future perspectives for molecular targeted nodal staging.

Subdermal Ultrasound Contrast Agent Injection for Sentinel Lymph Node Identification: An Analysis of Safety and Contrast Agent Dose in Healthy Volunteers

OBJECTIVES

Mapping of the lymphatic chain for identification of the sentinel lymph node (SLN) is an important aspect of predicting outcomes for patients with breast cancer, and it is usually performed as an intraoperative procedure using blue dye and/or radiopharmaceutical agents. Recently, the use of contrast-enhanced ultrasound (CEUS) has been proposed as an alternative imaging technique for this mapping. The objective of this study was to evaluate the use of subdermal administration of the ultrasound (US) contrast agent Sonazoid (GE Healthcare, Oslo, Norway) in terms of patient safety and to select the dose to be used for lymphatic applications in humans.

METHODS

This study was performed in 12 female volunteers who received bilateral subdermal injections of Sonazoid (1 or 2 mL dose) in the mid-upper outer quadrant of their breasts at 2 different time points. Contrast-enhanced US examinations were performed 0, 0.25, 0.5, 1, 2, 4, 6, and 24 hours after injection to identify SLNs.

RESULTS

Sentinel lymph nodes were identified within the first hour after injection as enhanced structures, and there was no significant difference by dose in the number of SLNs identified (P = .74). The volunteers only had minor adverse experiences (AEs) that resolved completely without intervention by study completion.

CONCLUSIONS

The subdermal use of Sonazoid in this study showed only minor local and nonsignificant AEs that were completely resolved without any intervention. Two different doses were compared with no significant differences observed between them. Hence, the lower dose studied (1 mL) was selected for use in future clinical studies.

Biological Subtypes of Breast Cancer and Sentinel Lymph Node Biopsy

Objective

Breast cancer subtypes are used as prognostic and predictive factors considering the genomic profile of the disease. This study is designed to investigate the Sentinel Lymph Node (SLN) detection rate in breast cancer for different biological characteristics.

Material and Methods

Patients on whom we performed the methylene blue method alone were named as Group I, radiocolloid substance method alone as Group II and both methylene blue and radiocolloid method as Group III. The results of biological tumor characteristics and characteristics of the patients on different SLN biopsy techniques were investigated.

Results

The overall SLN detecting success rate was 83.3%. When considered for each group, success rate was 80% for group I, 84.9% for group II and 90.6% for group III. While a success rate of 94.6% was achieved with radiocolloid only in the patients in Luminal A and B subgroup, 90% success rate was achieved in Her2 (+) and triple negative (TN) patients with combined method.

Conclusion

While successful results could be achieved by using radiocolloid substances alone in patients with Luminal A and B subtypes, combined methods should be used in HER2 (+) and TN patients.

Sentinel Lymph Node Mapping and Biopsy for Breast Cancer: A Review of the Literature Relative to 4791 Procedures

The status of axillary nodes is the most important prognostic factor in breast cancer to select patient subgroups for adjuvant chemotherapy; the current standard of care for surgical management of invasive breast cancer is complete removal of the tumor by either mastectomy or lumpectomy followed by axillary lymph node dissection (ALND). The recent introduction of intraoperative lymphatic mapping and sentinel lymph node biopsy (SLND) represents a major new opportunity for appropriate and less invasive surgical management of many tumors. There is an almost uniformly enthusiasm concerning the potential of this technique in breast carcinoma management, shown by published data. A peculiar attention to the so-called “sentinel node debate” in breast cancer surgery is a constant in the last years issues of the major medical journals. Even patients have become more aware about medical enthusiasm and their request of concise information on the topic and the possibilities of this approach is an increasing reality in medical practice.

The aim of this paper is to review recent literature to offer an overview about the main controversial methodological aspects and a wide analysis of reported results. The most significative international literature papers from Medline were retrieved from 1993 to September 1999, and 4782 procedures were analysed. This extensive review of the literature has confirmed accuracy, feasibility and reliability of the SN detecting technique in axillary mapping. Provided a good proficiency in SN localisation and pathological evaluation, human resources and efforts should be mainly focused on its clinical validation as an alternative to ALND instead of on further phase I–-II clinical studies.

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.

Study of Sentinel Lymph Node in Breast Cancer: Our Experience in 46 Cases

At the Surgery Department of Biella 46 patients were enrolled in a study on the sentinel lymph node (SN) in the period from 1 January 1999 to 30 September 1999. The aim of the study was to determine, on the basis of our own experience, the percentages of accuracy and concordance, and compare them with case series abroad and in Italy; in addition, we sought to establish a possible correlation between certain features of breast cancer and positivity of the axilla. The method utilized was lymphoscintigraphy and gamma probe. Fifteen cases with positive axillary lymph nodes and 12 cases with positive sentinel lymph nodes were found; there were no false positive and three false negative results. No migration of the tracer was observed with lymphoscintigraphy in two cases. The percentage of concordance obtained was 93.2% in the complete series and 96.5% in the subseries that excluded the learning curve. Comparing the percentage of concordance of our case series with those abroad and in Italy, an average overlapping percentage was obtained. The percentage of accuracy obtained in our study was 95.7%, which is slightly higher than the average of percentages of the case series abroad and in Italy.

Optical See-Through Cancer Vision Goggles Enable Direct Patient Visualization and Real-Time Fluorescence-Guided Oncologic Surgery

BACKGROUND

The inability to visualize the patient and surgical site directly, limits the use of current near infrared fluorescence-guided surgery systems for real-time sentinel lymph node biopsy and tumor margin assessment.

METHODS

We evaluated an optical see-through goggle augmented imaging and navigation system (GAINS) for near-infrared, fluorescence-guided surgery. Tumor-bearing mice injected with a near infrared cancer-targeting agent underwent fluorescence-guided, tumor resection. Female Yorkshire pigs received hind leg intradermal indocyanine green injection and underwent fluorescence-guided, popliteal lymph node resection. Four breast cancer patients received ^99mTc-sulfur colloid and indocyanine green retroareolarly before undergoing sentinel lymph node biopsy using radioactive tracking and fluorescence imaging. Three other breast cancer patients received indocyanine green retroareolarly before undergoing standard-of-care partial mastectomy, followed by fluorescence imaging of resected tumor and tumor cavity for margin assessment.

RESULTS

Using near-infrared fluorescence from the dyes, the optical see-through GAINS accurately identified all mouse tumors, pig lymphatics, and four pig popliteal lymph nodes with high signal-to-background ratio. In 4 human breast cancer patients, 11 sentinel lymph nodes were identified with a detection sensitivity of 86.67 ± 0.27% for radioactive tracking and 100% for GAINS. Tumor margin status was accurately predicted by GAINS in all three patients, including clear margins in patients 1 and 2 and positive margins in patient 3 as confirmed by paraffin-embedded section histopathology.

CONCLUSIONS

The optical see-through GAINS prototype enhances near infrared fluorescence-guided surgery for sentinel lymph node biopsy and tumor margin assessment in breast cancer patients without disrupting the surgical workflow in the operating room.

Periareolar or Peritumoral Injection of Isosulfan Blue and the Effect on the Number of Sentinel Lymph Nodes Examined

The conduct of sentinel node biopsy (SLNBx) for breast cancer (BC) has evolved substantially since its original description. No national standards for the performance of SLNBx exist, therefore, we sought to determine the effect of isosulfan blue (ISB) injection technique on nodal harvesting and staging accuracy during SLNBx. Our main outcome measures included the number of SLNs examined and the number of positive axillae in patients undergoing SLNBx after injection of filtered sulfur colloid intradermally and either small volume ISB injected in the periareolar dermis (PA,∼0.75 cc) or large volume peritumoral (PT, 5 cc). Between January 1, 2009, and September 30, 2013, 1357 patients at an academic/community practice setting underwent SLNBx of which 966 (71.2%) were node negative. These patients ranged in age from 27 to 97 years (mean 60.1 years). The majority of patients (76%) underwent PT injection of ISB. There was no significant difference in the mean age of these two groups (61.2 PT vs 59.7 PA years). All were female. The majority of patients (72.7%) had T1 primaries. Nearly 73 per cent of patients were Luminal A/B, 10.8 per cent HER, and 16.4 per cent were triple negative. There was no significant difference in the distribution of T stage (P = 0.56) or breast cancer subtypes between the techniques (P = 0.59). The mean number of nodes examined was 3.1 (range, 1–18). PT patients had a mean of 3.5 (range, 1–18) nodes, whereas PA patients had a mean of 2.4 nodes (range, 1–10) (P < 0.001). The technical aspects of injecting ISB affect the number of nodes harvested during SLNBx but not staging accuracy.

A mini-review on factors and countermeasures associated with false-negative sentinel lymph node biopsies in breast cancer

Sentinel lymph node biopsy (SLNB) is a new surgical technique for local axillary lymph nodes (ALNs) of breast cancer. Large-scale clinical trials have confirmed that undergoing SLNB and ALN dissection (ALND) showed no significant difference for sentinel lymph node (SLN)-negative patients in terms of disease-free survival, overall survival and recurrence-free survival. However, false-negative results are still the main concern of physicians as well as patients who undergo SLNB instead of ALND. The American Society of Breast Surgeons established a task force to suggest acceptable standards for SLNB. In 2000, the task force recommended that the identification rate for SLNB be 85% or higher and the false-negative rate be 5% or lower. This review focuses on clinical factors (tumor volume, multifocal/multi-center cancers, neoadjuvant chemotherapy and skip metastasis), tracer techniques and pathological factors affecting SLNB and explores methods for reducing the false-negative rate.

Preparation study of indocyanine green-rituximab: A new receptor-targeted tracer for sentinel lymph node in breast cancer

An appropriate receptor-targeted tracer for sentinel lymph node biopsy (SLNB) was prepared. We combined the fluorescence tracer (Indocyanine green, ICG) with Rituximab (a chimeric human/murine monoclonal antibody targeting the CD20 antigen on the surface of lymphocyte) directly to produce a new tracer (ICG-Rituximab). When the new tracer drains to the lymph node, Rituximab will combine with CD20 receptor on the B-cell surface in the lymph node. If the statue of antibody-receptor connection does not reach saturation, the number of Rituximab is less than CD20. With this appropriate injection dose, the new tracer could only stay in sentinel lymph node (SLN) and make it imaging. Positive fluorescence SLN was detected 12 minutes after injection with no other organs imaging. The imaging of SLN was stable and clear for 20-24 hours. Due to SLN stained with more ICG than the lymphatic vessel, the fluorescence situation of SLN would be brighter than the vessel. The surgeon can detect the positive fluorescence SLN easily without following the fluorescence imaging lymphatic vessel. The results of our preliminary study showed that the new tracer might be useful for improving SLN imaging and worth further clinical study. SLNB with the new tracer could be a convenient method for detecting SLN and would become a standard performance in clinical practice.

Is Sentinel Lymph Node Biopsy Necessary in Patients Undergoing Prophylactic Mastectomy? A Systematic Review and Meta-Analysis

The gain by performing sentinel lymph node biopsy (SLNB) during prophylactic mastectomy (PM) is debatable, and we performed a meta-analysis of existing literature to evaluate that the role of SLNB in subjects undergoing PM. A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. The search identified 11 relevant articles reporting on patients who underwent SLNB at the time of PM. Data were abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI). We included 14 studies comprising of 2,708 prophylactic mastectomies. Among 2,708 prophylactic mastectomies, the frequency of occult invasive cancer (51 cases) was 1.8% and the rate of positive SLNs (33 cases) was 1.2%. In 25 invasive cancers at the time of PM were found to have negative SLNs which avoided axillary lymph node dissection (ALND). In seven cases with positive SLNBs were found not to have invasive cancer at the time of PM and needed a subsequent ALND. Most of the patients with positive SLNs had locally advanced disease in the contralateral breast. SLNB may be suitable for patients with ipsilateral, locally advanced breast cancer and is not recommend for all patients undergoing PM.

Preoperative Scintigrams to Identify the Sentinel Lymph Node in Breast Cancer: a Waste of Time?

Sentinel lymph node biopsy (SLNB) remains the gold standard for assessing axillary node status in breast cancer. Preoperative scintigrams have been used to identify the sentinel lymph node (SLN); however, their use is controversial. Studies suggest they add little to successful SLN detection in theatre, immediately prior to node excision. They have been associated with high false negatives, time expense, patient dissatisfaction, and unnecessary costs. The aim of the present study was to evaluate the diagnostic accuracy of scintigrams in comparison to intraoperative SLN identification techniques. This study included all patients undergoing a SLNB for breast cancer from April 2010 to 2011. Scintigram reports, operation notes, and histology results were analyzed. Mann-Whitney U and chi-squared tests were used for statistical analysis of data. Two hundred nineteen female patients with a median age of 59.6 years (24.0-89.9 years) were included in this study. Scintigram was performed in 185 and not in 34 patients due to time constraints. Combined γ-probe and Isosulfan blue dye for SLN detection (intraoperative methods) have an identification rate of 98.2 % (p = 0.005), compared to 92.4 % (p = 0.088) from scintigrams alone. Scintigrams confer no additional advantage to the operating surgeon for successful SLN detection and excision in theatre. Intraoperative SLN identification is more accurate and reliable. Routine scintigram use is unjustified and should be withdrawn from current practice.

Partial mastectomy using manual blunt dissection (MBD) in early breast cancer

BACKGROUND

Breast-preserving surgery (Bp) and sentinel lymph node biopsy (SNB) are established as standard treatment for axillary lymph node-negative early breast cancer.

METHODS

A surgical technique using manual blunt dissection (MBD), in which use of electrocautery, an ultrasonically activated scalpel, and ligation is minimized, is described. This involves an approach from small incisions in the axilla or areola to avoid injury to skin flaps, and with adequate mobilization of the breast, so that regardless of the tumor site, surgical wounds are not noticeable. The usefulness and tolerability of this surgical technique were examined.

RESULTS

This surgical technique was evaluated in 233 patients. Surgery could be performed rapidly, with a mean operative time of 67 ± 21 min and a low mean blood loss of only 35 ± 28 ml. There was little need for postoperative analgesia, and surgery was well tolerated without postoperative bleeding or wound infection.

CONCLUSION

Our proposed technique for partial mastectomy using MBD provides good curative and cosmetic results.

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 biopsy under fluorescent indocyanin green guidance: Initial experience

OBJECTIVE

Sentinel lymph node biopsy can be applied by using either blue dye or radionuclide method or both in breast cancer. Fluorescent imaging with indocyanine green is a new defined method. This study evaluates the applicability of sentinel lymph node biopsy via fluorescent indocyanine green.

MATERIAL AND METHODS

IC-VIEW (Pulsion Medical Systems AG, Munich, Germany) infrared visualization system was used for imaging. Two mL of indocyanine green was injected to visualize sentinel lymph nodes. After injection, subcutaneous lymphatics were traced and sentinel lymph nodes were found with simultaneous imaging. Sentinel lymph nodes were excised under fluorescent light guidance, and excised lymph nodes were examined histopathologically. Patients with sentinel lymph node metastases underwent axillary dissection.

RESULTS

Four patients with sentinel lymph node biopsy due to breast cancer were included in the study. Sentinel lymph nodes were visualized with indocyanine green in all patients. The median number of excised sentinel lymph node was 2 (2-3). Two patients with lymph node metastasis underwent axillary dissection. No metastasis was detected in lymph nodes other than the sentinel nodes in patients with axillary dissection. There was no complication during and after the operation related to the method.

CONCLUSION

According to our limited experience, sentinel lymph node biopsy under fluorescent indocyanine green guidance, which has an advantage of simultaneous visualization, is technically feasible.

Sentinel Lymph Node Mapping of Liver

BACKGROUND

Although the sentinel lymph node (SLN) hypothesis has been applied to many tissues and organs, liver has remained unstudied. Currently, it is unclear whether hepatic SLNs even exist. If so, they could alter the management of intrahepatic cholangiocarcinoma and other hepatic malignancies by minimizing the extent of surgery while still providing precise nodal staging. This study investigated whether invisible yet tissue-penetrating near-infrared (NIR) fluorescent light can provide simultaneous identification of both the SLN and all other regional lymph nodes (RLNs) in the liver.

METHODS

In 25 Yorkshire pigs, this study determined whether SLNs exist in liver and compared the effectiveness of two clinically available NIR fluorophores [methylene blue and indocyanine green (ICG)], and two novel NIR fluorophores previously described by our group (ESNF14 and ZW800-3C) for SLN and RLN mapping.

RESULTS

In this study, ESNF14 showed the highest signal-to-background ratio and the longest retention time in SLNs without leakage to second-tier lymph nodes. The findings showed that ICG had apparent leakage to second-tier nodes, and ZW800-3C had poor migration after intraparenchymal injection. However, when injected intravenously, ZW800-3C was able to highlight all RLNs in liver during a 4- to 6-h period. Simultaneous dual-channel imaging of SLN (ESNF14) and RLN (ZW800-3C) permitted unambiguous identification and image-guided resection of SLNs and RLNs in liver.

CONCLUSION

The NIR imaging technology enables real-time intraoperative identification of SLNs and RLNs in the liver of swine. If these results are confirmed in patients, new strategies for the surgical management of intrahepatic malignancies should be possible.

Recent advances in near-infrared fluorescence-guided imaging surgery using indocyanine green

Near-infrared (NIR) fluorescence imaging has better tissue penetration, allowing for the effective rejection of excitation light and detection deep inside organs. Indocyanine green (ICG) generates NIR fluorescence after illumination by an NIR ray, enabling real-time intraoperative visualization of superficial lymphatic channels and vessels transcutaneously. The HyperEye Medical System (HEMS) can simultaneously detect NIR rays under room light to provide color imaging, which enables visualization under bright light. Thus, NIR fluorescence imaging using ICG can provide for excellent diagnostic accuracy in detecting sentinel lymph nodes in cancer and microvascular circulation in various ischemic diseases, to assist us with intraoperative decision making. Including HEMS in this system could further improve the sentinel lymph node mapping and intraoperative identification of blood supply in reconstructive organs and ischemic diseases, making it more attractive than conventional imaging. Moreover, the development of new laparoscopic imaging systems equipped with NIR will allow fluorescence-guided surgery in a minimally invasive setting. Future directions, including the conjugation of NIR fluorophores to target specific cancer markers might be realistic technology with diagnostic and therapeutic benefits.

Preoperative diagnosis of sentinel lymph node (SLN) metastasis using 3D CT lymphography (CTLG)

BACKGROUND

Sentinel lymph node biopsy (SLNB) became a standard procedure for patients with early breast cancer, however, an indication of SLN navigation to metastatic disease may lead to misdiagnosis for staging. Preoperative CTLG with a water-soluble iodinated contrast medium visualizes the correct primary SLNs and its afferent lymphatic channels surrounding detailed anatomy, therefore it can predict LN metastasis by visualizing the lymph vessel obstruction or stain defect of the SLN by tumor. The current study presents the value of CTLG for preoperative prediction for SLN status.

METHODS

A total of 228 patients with Tis-T2 breast cancer who did not receive primary chemotherapy were studied. SLN metastasis was diagnosed according to the following staining patterns of SLNs and afferent lymphatic vessels: stain defect of SLN, obstruction, stagnation, dilation, and detour of the lymphatic vessels by tumor occupation. The diagnosis was compared with the pathological results to evaluate the accuracy of prediction for SLN metastasis using CTLG.

RESULTS

Twenty-seven of 228 patients had metastatic SLN pathologically. Twenty-five of these were diagnosed as metastatic preoperatively. The accuracy for metastatic diagnosis using CTLG was 89.0%, sensitivity was 92.6%, and specificity was 88.6%. The positive predictive value was 52.1% and negative predictive value was 98.8%.

CONCLUSION

CTLG can select the candidate with truly node negative cases in early breast cancer patients, because it predicts lymph node metastasis preoperatively from natural status of the lymphographic image. It also might omit the SLN biopsy itself.

Diagnostic accuracy of sentinel node identification is maintained with the addition of local lidocaine and subareolar radioactive colloid injection

Preoperative sentinel node localization (SNL) using a subareolar injection of radiotracer technetium-99m-sulfur colloid (Tc(99m)SC) is associated with significant pain. Lidocaine use during SNL is not widely adopted partly due to a concern that it can obscure sentinel node identification and reduce its diagnostic accuracy. We prospectively identified women with a biopsy-proven infiltrating breast cancer who were awaiting a SNL. The women completed the McGill pain questionnaire, Visual Analog Scale, and Wong-Baker FACES Pain Rating Scale prior to and following SNL. We identified a retrospective cohort of women with similar demographic and tumor characteristics who did not receive lidocaine before SNL. We compared sentinel lymph node identification rates in the two cohorts. We used Wilcoxon rank sum tests to compare continuous measures and Fisher's exact test for categorical measures. Between January 2011 to July 2012, 110 women consented, and 105 were eligible for and received lidocaine prior to Tc(99m)SC injection. The post-lidocaine identification rate of SNL was 95 % with Tc(99m)SC, and 100 % with the addition of intraoperative methylene blue dye/saline. Pain range prior to and following the SNL was unchanged (P = 0.703). We identified 187 women from 2005 to 2009 who did not receive lidocaine during preoperative SNL. There was no significant difference in the success rate of SNL, with or without lidocaine (P = 0.194). The administration of lidocaine during SNL prevents pain related to isotope injection while maintaining the success rate. We have changed our practice at our center to incorporate the use of lidocaine during all SNL.

The Role of Sentinel Lymph Node Biopsy and Factors Associated with Invasion in Extensive DCIS of the Breast Treated by Mastectomy: The Cinnamome Prospective Multicenter Study

Background

When invasive components are discovered at mastectomy for vacuum-assisted biopsy (VAB)-diagnosed ductal carcinoma in situ (DCIS), the only option available is axillary lymph node dissection (ALND). The primary aim of this prospective multicenter trial was to determine the benefit of performing upfront sentinel lymph node (SLN) biopsy for these patients. The secondary aim was to determine DCIS factors associated with microinvasion or invasion.

Methods

The SLN procedure was performed during mastectomy, and for positive SLN an ALND was performed during the same intervention. A tissue microarray containing DCIS lesions from the mastectomy specimens was subsequently performed.

Results

From May 2008 to December 2010, 228 patients were enrolled from 14 French cancer centers, including 192 eligible patients with pure DCIS on VAB and successful SLN procedures. ALND was avoided for 51 [67 %; 95 % confidence interval (CI), 56–77 %] of all the patients who had microinvasive DCIS or DCIS associated with invasive carcinoma at mastectomy and a negative SLN. Of the 192 patients, 76 (39 %) with VAB-diagnosed DCIS were upgraded after mastectomy to micro (n = 20) or invasive disease (n = 56). The rate of positive SLN for patients with DCIS on VAB was 14 %. High nuclear grade of DCIS was associated with greater risk of microinvasion and invasion, and HER2-amplified DCIS was associated with greater risk of invasion.

Conclusions

Underestimation of invasive components is high when DCIS is diagnosed by VAB in patients undergoing mastectomy. Upfront SLN for patients with VAB-diagnosed extensive DCIS avoids unnecessary ALND for two-thirds of patients with micro or invasive disease on mastectomy.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-015-4476-5) contains supplementary material, which is available to authorized users.

Evolution of sentinel lymph node biopsy in breast cancer, in and out of vogue?

Sentinel lymph node biopsy (SLNB) was introduced 2 decades ago and thereafter validated for routine surgical management of breast cancer, including cases treated with neoadjuvant chemotherapy. As the number of lymph nodes for staging has decreased, pathologists have scrutinized SLN with a combination of standard hematoxylin and eosin, levels, immunohistochemistry (IHC), and molecular methods. An epidemic of small-volume metastases thereby arose, leading to modifications in the American Joint Committee on Cancer staging to accommodate findings such as isolated tumor cells (ITC) and micrometastases. With the goal of determining the significance of these findings, retrospective followed by prospective trials were performed, showing mixed results. The ACOSOG Z10 and NSABP B-32 trials both independently showed that ITC and micrometastases were not significant and thus discouraged the use of levels and IHC for detecting them. However, the Surveillance Epidemiology and End Results database showed that patients with micrometastases had an overall decreased survival. In addition, the MIRROR (Micrometastases and ITC: Relevant and Robust or Rubbish?) trial, showed that patients with ITC and micrometastases treated with adjuvant therapy had lower hazard ratios compared with untreated patients. Subsequently, the ACOSOG Z0011 trial randomized patients with up to 2 positive SLN to axillary lymph node dissection (ALND) or not, all treated with radiation and chemotherapy, showing no difference in survival or recurrence rates between the 2 groups and causing a shift from ALND. As the rate of ALND has declined, the necessity of performing levels, IHC, frozen section, and molecular studies on SLN needs to be revisited.

Breast cancer and sentinel lymph node micrometastases: indications for lymphadenectomy and literature review

An increasingly early diagnosis for discovering breast cancer, an improvement of surgical procedures with refining techniques for research and study of sentinel node, currently allow a more conservative surgical approach. Association with suitable chemo-radiotherapy allows a good control of breast disease. Our study, although modest, was carried out on 63 patients suffering from breast cancer, who underwent surgical treatment with assessment of sentinel lymph node. Aim of study was to establish the most correct strategy in the presence of isolated tumor cells (ITC) and/or micro-metastases of sentinel lymph node. Many studies have been carried out to find which was the most appropriate treatment, nevertheless, in the absence of univocal guidelines, we prefer to proceed to axillary dissection, though the topic is very debated and controversial. Following this strategy we obtained quite satisfactory results.

The clinical value of hybrid sentinel lymphoscintigraphy to predict metastatic sentinel lymph nodes in breast cancer

PURPOSE

Hybrid imaging techniques can provide functional and anatomical information about sentinel lymph nodes in breast cancer. Our aim in this study was to evaluate which imaging parameters on hybrid sentinel lymphoscintigraphy predicted metastatic involvement of sentinel lymph nodes (SLNs) in patients with breast cancer.

METHODS

Among 56 patients who underwent conventional sentinel lymphoscintigraphy, 45 patients (age, 53.1 ± 9.5 years) underwent hybrid sentinel lymphoscintigraphy using a single-photon emission computed tomography (SPECT)/computed tomography (CT) gamma camera. On hybrid SPECT/CT images, we compared the shape and size (long-to-short axis [L/S] ratio) of the SLN, and SLN/periareolar injection site (S/P) count ratio between metastatic and non-metastatic SLNs. Metastatic involvement of sentinel lymph nodes was confirmed by pathological biopsy.

RESULTS

Pathological biopsy revealed that 21 patients (46.7 %) had metastatic SLNs, while 24 (53.3 %) had non-metastatic SLNs. In the 21 patients with metastatic SLNs, the SLN was mostly round (57.1 %) or had an eccentric cortical rim (38.1 %). Of 24 patients with non-metastatic SLNs, 13 patients (54.1 %) had an SLN with a C-shape rim or eccentric cortex. L/S ratio was 2.04 for metastatic SLNs and 2.38 for non-metastatic SLNs. Seven (33 %) patients had T1 primary tumors and 14 (66 %) had T2 primary tumors in the metastatic SLN group. In contrast, 18 (75 %) patients had T1 primary tumors and six (25 %) had T2 tumors in the non-metastatic SLN group. S/P count ratio was significantly lower in the metastatic SLN group than the non-metastatic SLN group for those patients with a T1 primary tumor (p = 0.007).

CONCLUSIONS

Hybrid SPECT/CT offers the physiologic data of SPECT together with the anatomic data of CT in a single image. This hybrid imaging improved the anatomic localization of SLNs in breast cancer patients and predicted the metastatic involvement of SLNs in the subgroup of breast cancer patients with T1 primary tumors.

Use of Fluorescence Imaging in Combination with Patent Blue Dye versus Patent Blue Dye Alone in Sentinel Lymph Node Biopsy in Breast Cancer

PURPOSE

Near-infrared fluorescence imaging with indocyanine green (ICG) has the potential to improve sentinel lymph node (SLN) mapping in breast cancer. In this clinical trial, we compared the potential value of ICG combined with blue dye with that of blue dye alone for detecting SLNs.

METHODS

Patients undergoing SLN biopsy (SLNB) between November 2010 and November 2013 were included. Up to December 2011, SLNs were detected by using patent blue (PB) alone, and since January 2012, by using PB in combination with ICG. The patients were divided into the following two groups: group A (ICG-PB; n=96) and group B (PB; n=73), and SLN detection parameters were compared between the groups. All patients underwent level I and II axillary dissections after SLNB.

RESULTS

In group A, the SLN detection rate was 96.9% (93/96), the accuracy of detection was 98.9% (92/93), and the false-negative rate (FNR) was 3.4% (1/29). In group B, the SLN detection rate was 84.9% (62/73), the accuracy of detection was 96.8% (60/62), and the FNR was 11.1% (2/18). The ICG-PB group showed significantly superior results compared to the PB group for SLN detection (p=0.005) and a greatly improved FNR.

CONCLUSION

The combined fluorescence and blue dye-based tracer technique was superior to the use of blue dye alone for identifying SLNs, and for predicting axillary lymph node status in patients with breast cancer; in addition, the combined technique had reduced false-negative results.

Prospective evaluation of the feasibility of sentinel lymph node biopsy in breast cancer patients with negative axillary conversion after neoadjuvant chemotherapy

Purpose

Tumor response to neoadjuvant chemotherapy (NAC) may adversely affect the identification and accuracy rate of sentinel lymph node biopsy (SLNB). This study was conducted to evaluate the feasibility of SLNB in node-positive breast cancer patients with negative axillary conversion after NAC.

Materials and Methods

Ninety-six patients with positive nodes at presentation were prospectively enrolled. ¹⁸Fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG PET) and ultrasonography were performed before and after NAC. A metastatic axillary lymph node was defined as positive if it was positive upon both ¹⁸F-FDG PET and ultrasonography, while it was considered negative if it was negative upon both ¹⁸F-FDG PET and ultrasonography.

Results

After NAC, 55 cases (57.3%) became clinically node-negative, while 41 cases (42.7%) remained node-positive. In the entire cohort, the sentinel lymph node (SLN) identification and false-negative rates were 84.3% (81/96) and 18.4% (9/49), respectively. In the negative axillary conversion group, the results of SLNB showed an 85.7% (48/55) identification rate and 16.7% (4/24) false-negative rate.

Conclusion

For breast cancer patients with clinically positive nodes at presentation, it is difficult to conclude whether the SLN accurately represents the metastatic status of all axillary lymph nodes, even after clinically negative node conversion following NAC.

Optimization of sentinel lymph node mapping in bladder cancer using near-infrared fluorescence imaging

BACKGROUND AND OBJECTIVES

Unlike other cancers, the Sentinel Lymph Node (SLN) procedure in bladder cancer requires special attention to the injection technique. The aim of this study was to assess feasibility and to optimize tracer injection technique for SLN mapping in bladder cancer patients using NIR fluorescence imaging.

METHODS

Twenty patients with invasive bladder cancer scheduled for radical cystectomy were prospectively enrolled. Indocyanine green (ICG) bound to human serum albumin (complex ICG:HSA; 500 µM) was injected peritumourally to permit SLN mapping. ICG:HSA was first administrated serosally (n = 5), and subsequently mucosally by cystoscopic injection (n = 15). In the last cohort of 12 patients treated with cystoscopic injection, the bladder was kept filled with saline for at least 15 min.

RESULTS

Fluorescent lymph nodes were observed only in the patient group with cystoscopic injection of ICG:HSA. Filling of the bladder post-injection was of added value to promote drainage of ICG:HSA to the lymph nodes, and in 11 of these 12 patients (92%) one or more NIR fluorescent lymph nodes were identified.

CONCLUSIONS

The current study demonstrates proof-of-principle of using NIR fluorescence imaging for SLN identification in bladder cancer. Cystoscopic injection with distension of the bladder appears optimal for SLN mapping.