Sentinel Lymph Node Methods in Breast Cancer

Value of sentinel node ultrastaging and pathologic techniques in tumoral detection

PURPOSE OF REVIEW

Sentinel lymph node assessment is an option for patients with clinically early-stage vulvar cancer, endometrial cancer, cervical cancer, and, more recently, ovarian cancer. However, although ultrastaging is mandatory as part of the node evaluation, universally accepted pathology protocols are lacking. This review focuses on the current evidence for the most relevant aspects of sentinel lymph node evaluation, as well as some controversial topics like frozen section or one-step nucleic acid amplification.

RECENT FINDINGS

The diagnostic accuracy of sentinel lymph node detection algorithms for patients with gynecologic neoplasms is high. However, the heterogeneity among the published studies and the absence of clear recommendations from most guidelines make it challenging to recommend one protocol over another. The minimum requirement from ultrastaging protocols (regarding the number of levels to be assessed, among others) to get the highest accuracy with a minor cost is unknown.

SUMMARY

Sentinel lymph node evaluation is now part of the surgical management for most early-stage gynecologic neoplasms. However, a universally accepted ultrastaging pathology protocol is lacking in literature and clinical practice. This gap requires significant effort from the gynecologic oncology and pathology community to be closed and then to allow advancements in surgical management for early-stage gynecologic tumors to go forward.

Non-invasive prediction of axillary lymph node dissection exemption in breast cancer patients post-neoadjuvant therapy: A radiomics and deep learning analysis on longitudinal DCE-MRI data

PURPOSE

In breast cancer (BC) patients with clinical axillary lymph node metastasis (cN+) undergoing neoadjuvant therapy (NAT), precise axillary lymph node (ALN) assessment dictates therapeutic strategy. There is a critical demand for a precise method to assess the axillary lymph node (ALN) status in these patients.

MATERIALS AND METHODS

A retrospective analysis was conducted on 160 BC patients undergoing NAT at Fujian Medical University Union Hospital. We analyzed baseline and two-cycle reassessment dynamic contrast-enhanced MRI (DCE-MRI) images, extracting 3668 radiomic and 4096 deep learning features, and computing 1834 delta-radiomic and 2048 delta-deep learning features. Light Gradient Boosting Machine (LightGBM), Support Vector Machine (SVM), RandomForest, and Multilayer Perceptron (MLP) algorithms were employed to develop risk models and were evaluated using 10-fold cross-validation.

RESULTS

Of the patients, 61 (38.13 %) achieved ypN0 status post-NAT. Univariate and multivariable logistic regression analyses revealed molecular subtypes and Ki67 as pivotal predictors of achieving ypN0 post-NAT. The SVM-based "Data Amalgamation" model that integrates radiomic, deep learning features, and clinical data, exhibited an outstanding AUC of 0.986 (95 % CI: 0.954-1.000), surpassing other models.

CONCLUSION

Our study illuminates the challenges and opportunities inherent in breast cancer management post-NAT. By introducing a sophisticated, SVM-based "Data Amalgamation" model, we propose a way towards accurate, dynamic ALN assessments, offering potential for personalized therapeutic strategies in BC.

Intraoperative Imaging Techniques in Oncology

Imaging-based procedures have become well integrated into the diagnosis and management of oncological patients and play a significant role in reducing morbidity and mortality rates. Here we describe the established and upcoming surgical oncological imaging techniques and their impact on cancer management.

Steerable DROP-IN radioguidance during minimal-invasive non-robotic cervical and endometrial sentinel lymph node surgery

PURPOSE

The recently introduced tethered DROP-IN gamma probe has revolutionized the way robotic radioguided surgery is performed, fully exploiting the nature of steerable robotic instruments. Given this success, the current first-in-human study investigates if the DROP-IN can also provide benefit in combination with steerable non-robotic instruments during conventional laparoscopic surgery, showing equivalence or even benefit over a traditional rigid gamma probe.

METHODS

The evaluation was performed in ten patients during laparoscopic cervical (n = 4) and endometrial (n = 6) cancer sentinel lymph node (SLN) procedures. Surgical guidance was provided using the hybrid, or bi-modal, SLN tracer ICG-99mTc-nanocolloid. SLN detection was compared between the traditional rigid laparoscopic gamma probe, the combination of a DROP-IN gamma probe and a steerable laparoscopic instrument (LaproFlex), and fluorescence imaging.

RESULTS

The gynecologists experienced an enlarged freedom of movement when using the DROP-IN + LaproFlex combination compared to the rigid laparoscopic probe, making it possible to better isolate the SLN signal from background signals. This did not translate into a change in the SLN find rate yet. In both cervical and endometrial cancer combined, the rigid probe and DROP-IN + LaproFlex combination provided an equivalent detection rate of 96%, while fluorescence provided 85%.

CONCLUSION

We have successfully demonstrated the in-human use of steerable DROP-IN radioguidance during laparoscopic cervical and endometrial cancer SLN procedures, expanding the utility beyond robotic procedures. Indicating an improved surgical experience, these findings encourage further investigation and consideration on a path towards routine clinical practice and improved patient outcome.

TRIAL REGISTRATION

HCB/2021/0777 and NCT04492995; https://clinicaltrials.gov/study/NCT04492995.

Concordance between freehand SPECT and conventional scintigraphy for sentinel lymph node detection in breast cancer

INTRODUCTION

Freehand SPECT can be a useful imaging technique for preoperative planning of sentinel lymph node biopsy (SLNB) as it allows localization of the sentinel node by 3D and real-time tomographic imaging and determines its depth after a few minutes of scanning. The aim of the study was to evaluate the correlation between the number of detected SNs between freehand SPECT images and lymphoscintigraphy (LS).

MATERIALS AND METHODS

100 patients with a diagnosis of invasive breast cancer and no clinical evidence of lymph node involvement prospectively underwent SLNB. The preoperative study included freehand SPECT imaging at 15min after injection and LS imaging at 25 and 60-90min after injection (early and late). The observed agreement was analyzed and a concordance study was performed between the number of SNs detected with freehand SPECT and LS.

RESULTS

The observed agreement in the detection of SNs between freehand SPECT and early LS was 72%; between freehand SPECT and late LS was 85%; and between early and late LS was 87%. In the concordance study, there was moderate concordance between freehand SPECT and early LS (kappa coefficient: 0.42); moderate-high concordance between freehand SPECT and late LS (kappa coefficient: 0.60); and moderate-high concordance between early and late LS (kappa coefficient: 0.70), with no significant differences between them (p-value=0.16).

CONCLUSION

Freehand SPECT showed a moderate-high concordance with conventional imaging studies and could be a valid alternative for the presurgical study of SLNB in breast cancer.

Multidisciplinary radio-guided surgery team: Alternative to change the current paradigm

INTRODUCTION

Given the constant increase in the healthcare demand for examinations related to radio-guided surgery (RGS), our hospital adopted new professional profiles in the RGS team, in order to partially reduce the time spent by nuclear medicine physicians on this task.

AIM

To analyze the process of incorporating the profiles of Diagnostic Imaging Technician (DIT) and Sentinel Node Referent Nurse (SNRN), evaluating their deployment in the procedures linked to the technique.

MATERIAL AND METHODS

Analysis of RGS activity during the period 2018-2022, focusing on pre-surgical and surgical procedures related to breast cancer (BC) and malignant melanoma (MM), as they are those pathologies on which the transfer of care competencies was concentrated. Chronological evolution of the competencies assumed by the different profiles during their integration into the RGS team.

RESULTS

RGS's healthcare activity during the analyzed period experienced an increase of 109%. BC and MM were the pathologies that accounted for by far the greatest demand for care. The transfer of competencies in these two pathologies occurred in a progressive and staggered manner, with 74% (460/622) of the administration phase being carried out by the SNRN and 64% (333/519) of the surgeries by the DIT in 2022.

CONCLUSIONS

The creation of a multidisciplinary RGS team that includes different professional profiles (nuclear medicine physician [MN], ERGC and TSID) is an effective strategy to respond to the increase in the complexity and number of all procedures related to RGS.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

Assessing the Sentimag system for guiding sentinel node biopsies in patients with breast cancer

INTRODUCTION

Sentinel lymph node biopsy for breast cancer is a method to localize and excise the first draining lymph node from an invasive cancer of the breast. The histopathologic evaluation of the sentinel lymph node is used for predicting recurrence and survival and thus, guiding oncologists for treatment-decision making to administer adjuvant therapies. The ability to identify the sentinel node depends on methods to map lymphatic drainage from the breast to the sentinel node and accurately discriminate that node from other non-sentinel lymph nodes of the axilla.

AREAS COVERED

This review covers the clinical demand for technologies to assist the surgeon in intraoperative lymphatic mapping to specifically identify the sentinel lymph node in patients with breast cancer. Performance characteristics are reviewed for superparamagnetic iron oxide tracers used in lymphatic mapping compared to other current available technologies for lymphatic mapping.

EXPERT OPINION

The Magtrace (superparamagnetic iron oxide tracer) Sentimag (handheld magnetic probe) system is an FDA-approved technology for intraoperative lymphatic mapping to facilitate sentinel lymph node biopsy in breast cancer with technologic performance characteristics that are equivalent to 99Technetium-sulfur colloid. Barriers to broader utilization primarily center around the need for nonmetallic devices to be used for the conduct of surgery, which would interfere with the paramagnetic method for tracer localization.

Nano-tracers for sentinel lymph node detection: current trends in technique and application

Sentinel lymph node (SLN) detection and biopsy is a critical staging component for several cancers. Apart from established methods using dyes or radiolabeled colloids, newer techniques are emerging, like near-infrared fluorescent compounds, targeted molecular radiopharmaceuticals and magnetic nano-tracers. In the overview section of this review, we categorize SLN detection tracers based on their principle of use. We discuss the merits of existing tracers and provide a glimpse of in-development formulations. A subsequent clinical section explores the expanded role of SLN detection in management of various cancers, citing current medical guidelines and the leading conclusions of long-term clinical trials. The concluding section tries to provide a perspective of promising developments and the work required to bring them to clinical fruition.

Axillary Lymphadenectomy: Safe Dissection Through a Correct Technique

The primary treatment of breast cancer in sentinel-positive ganglia includes axillary lymphatic nodal dissection. The LAD (lymphatic axillary dissection) has decreased in overall numbers but due to the increasing incidence of breast cancer, it is practised on a daily basis, even though there is a myriad of complications such as numbness of the upper limb and chest wall, movement restriction of the upper limb, and chronic pain which appear due to trauma to the nerves which pass through the axilla. However, the utility in the overall survival or DFS (disease-free survival) of the patient is unquestionable.  In our study, through the dissection of cadavers, we exposed the vital structures and the anatomical relations of this region. We aimed to offer a map or technique for the surgeon to follow to decrease the overall morbidity of this procedure.

Sentinel node in breast cancer as an indicator of quality in medical care: Evaluation of statistics in Colombia

BACKGROUND

Sentinel lymph node biopsy in breast cancer is considered the standard of staging in cases of clinically negative lymph nodes. Its omission in favor of axillary dissection generates significant morbidity.

OBJECTIVE

To determine the total number of sentinel node biopsy procedures in breast cancer in Colombia from 2017 through 2020, model and analyze them as if they were performed only in stage I breast cancer patients, and integrate their results into the concepts of quality of medical care.

METHODS

Search in a database of the Ministry of Health and Social Protection of Colombia with sentinel lymph node biopsy codes, and filters of breast cancer and year. Their results are contrasted with the number of cases in stage I of breast cancer.

RESULTS

Breast cancer TNM staging was reported in 22154 cases, 3648 stage I. In the same time frame, the number of sentinel lymph node biopsies for breast cancer in Colombia was 1045, 28.64% of the total cases reported in stage I.

CONCLUSIONS

Colombia is far from complying with the standard indicator of sentinel lymph node biopsy. It is recommended to concentrate breast cancer cases in hospitals that provide the conditions for its performance.

Comparison of Sentinel Lymph Node Biopsy by Blue Dye Conjunction With Indocyanine Green or Radioisotope in Early-Stage Breast Cancer: A Prospective Single-Center Observational Study

Background

Although radioisotope (RI) combined with blue dye (BD) is the standard technique for sentinel lymph node (SLN) biopsy in breast cancer, the use of RI is limited at some institutions due to the specific equipment needed. Indocyanine green (ICG) fluorescence detection has been developed as a potential substitute for RI method. However, reports on the sensitivity of ICG and RI techniques in detecting SLN are inconsistent; hence, the present study was designed to compare the clinical efficacy between the combined method of ICG + BD (ICG-B) and RI + BD (RI-B).

Methods

A prospective observational study was performed that identified 138 breast cancer patients who had undergone lymphatic mapping and SLN biopsy with ICG-B or RI-B. The SLN detection rate, positive SLN counts, and lymph node metastasis between the 2 groups were compared.

Results

A total of 71 patients were recruited in the ICG-B group, while 67 were recruited in the RI-B group. The SLN detection rate was 100% in both the ICG-B and RI-B groups. Lymph node metastasis was found in 13 patients using ICG-B and in 12 patients using the RI-B technique (18.31% vs 17.91%, respectively; P = .61). No significant differences were observed in the positive SLN counts (3.12 ± 2.01 vs 3.33 ± 2.24, P = .37) between the 2 groups.

Conclusions

Indocyanine green combined with BD has an equal efficacy compared with RI plus BD when performing an axillary SLN biopsy in breast cancer. The ICG plus BD procedure is a promising alternative to traditional standard mapping methods.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Role of Nuclear Sentinel Lymph Node Mapping Compared to New Alternative Imaging Methods

With the emergence of sentinel node technology, many patients can be staged histopathologically using lymphatic mapping and selective lymphadenectomy. Structural imaging by using US, CT and MR permits precise measurement of lymph node volume, which is strongly associated with neoplastic involvement. Sentinel lymph node detection has been an ideal field of application for nuclear medicine because anatomical data fails to represent the close connections between the lymphatic system and regional lymph nodes, or, more specifically, to identify the first draining lymph node. Hybrid imaging has demonstrated higher accuracy than standard imaging in SLN visualization on images, but it did not change in terms of surgical detection. New alternatives without ionizing radiations are emerging now from "non-radiological" fields, such as ophthalmology and dermatology, where fluorescence or opto-acoustic imaging, for example, are widely used. In this paper, we will analyze the advantages and limits of the main innovative methods in sentinel lymph node detection, including innovations in lymphoscintigraphy techniques that persist as the gold standard to date.

Detection of Sentinel Lymph Nodes During Breast Cancer Surgery: A Literature Overview

Introduction. Detecting metastases is an important part of successful breast cancer treatment. Usually, the tumor tissue first spreads to the sentinel lymph nodes. Removal of the latter during surgery and histological examination allows to assess the patient’s di­sease stage, prognosis and treatment. The literature provides more than one approach or a combination of them, allowing us to accurately identify the breast’s sentinel lymph nodes and avoid removing all axillary lymph nodes. Purpose. To review the methods of intraoperative detection of breast sentinel lymph nodes presented in the literature. Research material and methods. Publications were searched using the specialized information search system Google Scholar. Keywords used in the search: breast sentinel lymph nodes, intraoperative detection. After evaluating the exclusion criteria, the review was based on 25 scientific publications. Results. 4 individual measures and 2 combinations of them can be used to detect sentinel breast lymph nodes during surgery. The materials used can be injected in 6 different ways. Conclusions. The combination of technetium-99m radiocolloid and methylene blue can be evaluated as the best method for intraoperative detection of sentinel lymph nodes in breast cancer patients. On the other hand, due to radiation and operating costs, more attention is being paid to the use of indocyanine green, superparamagnetic iron oxide, methylene blue dye, and the detection of metastases without surgery. Superficial methods of injecting the substance should be combined with deep ones due to the possibility of detecting extra-axillary sentinel lymph nodes of the breast. Ultimately, all decisions must be made on a case-by-case basis.

Management of Early-Stage Vulvar Cancer

Simple Summary

Vulvar cancer is a rare gynecological malignancy that affects mainly postmenopausal women. Recently, however, an alarming increase in the rates among young women has been observed due to human papillomavirus infection. The standard treatment for vulvar cancer is surgery with or without radiotherapy as adjuvant treatment. In recent decades, sentinel lymph node biopsy has been included as part of the surgical treatment. Thus, our objective was to review and discuss the advances found in the literature about early-stage vulvar cancer. For this, we searched PubMed for publications in the English language. Relevant articles, such as the GROINS-V studies, and the GOG protocols, are presented in this review exhibiting the evolution of early-stage vulvar cancer treatment and the decrease in surgical morbidity rates.

Abstract

Vulvar cancer is a rare gynecological malignancy since it represents 4% of all cancers of the female genital tract. The most common histological type is squamous cell carcinoma (90%). This type can be classified into two clinicopathological subtypes according to the etiology. The first subtype is associated with persistent human papillomavirus infection and is usually diagnosed in younger women. The second subtype is associated with lichen sclerosus condition, and in most cases is diagnosed in postmenopausal women. Currently, an increase in first subtype cases has been observed, which raised the concern about associated mortality and treatment morbidity among young women. Vulvar cancer treatment depends on histopathology grade and staging, but surgery with or without radiotherapy as adjuvant treatment is considered the gold standard. In recent decades, sentinel lymph node biopsy has been incorporated as part of the treatment. Therefore, we sought to review and discuss the advances documented in the literature about vulvar cancer focusing on the treatment of early-stage disease. Relevant articles, such as the GROINS-V studies and the GOG protocols, are presented in this review. Additionally, we discuss key points such as the evolution of treatment from invasive surgery with high morbidity, to more conservative approaches without compromising oncologic safety; the role of sentinel lymph node mapping in the initial staging, since it reduces the complications caused by inguinofemoral lymphadenectomy; the recurrences rates, since local recurrence is common and curable, however, groin-associated, or distant recurrences have a poor prognosis; and, finally, the long-term follow-up that is essential for all patients.

The Potential Value of m6A RNA Methylation in the Development of Cancers Focus on Malignant Glioma

N6-methyladenosine (m6A) RNA methylation is an epigenetic modification that has emerged in the last few years and has received increasing attention as the most abundant internal RNA modification in eukaryotic cells. m6A modifications affect multiple aspects of RNA metabolism, and m6A methylation has been shown to play a critical role in the progression of multiple cancers through a variety of mechanisms. This review summarizes the mechanisms by which m6A RNA methylation induced peripheral cancer cell progression and its potential role in the infiltration of immune cell of the glioblastoma microenvironment and novel immunotherapy. Assessing the pattern of m6A modification in glioblastoma will contribute to improving our understanding of microenvironmental infiltration and novel immunotherapies, and help in developing immunotherapeutic strategies.