Sentinel lymph node biopsy in breast cancer guided by CT lymphography; History, evolution and current applications

New Alternative Techniques for Sentinel Lymph Node Biopsy

Background and Objectives: This review paper highlights the key alternatives to the blue dye/radioisotope method of sentinel lymph node biopsy (SLNB). It analyses the research available on these alternative methods and their outcomes compared to the traditional techniques. Materials and Methods: This review focused on fifteen articles, of which five used indocyanine green (ICG) as a tracer, four used magnetic tracers, one used one-step nucleic acid amplification (OSNA) and Metasin (quantitative reverse transcriptase-polymerase chain reaction), one used the photosensitiser talaporfin sodium, one used sulphur hexafluoride gas microbubbles, one used CT-guided lymphography and two focused on general SLNB technique reviews. Results: Of the 15 papers analysed, the sentinel node detection rates were 69-100% for indocyanine green, 91.67-100% for magnetic tracers, 81% for talaporfin sodium, 9.3-55.2% for sulphur hexafluoride gas microbubbles, 90.5% for CTLG and 82.7-100% for one-step nucleic acid amplification. Conclusions: Indocyanine green fluorescence (ICG) and magnetic tracers have been proven non-inferior to traditional blue dye and isotope regarding SLNB localisation. Further studies are needed to investigate the use of these techniques in conjunction with each other and the possible use of language learning models. Dedicated studies are required to assess cost efficacy and longer-term outcomes.

The Sentinel Lymph Node in Treatment Planning: A Narrative Review of Lymph-Flow-Guided Radiotherapy

The sentinel lymph node technique is minimally invasive and used routinely by surgeons, reducing the need for morbid extensive lymph node dissections, which is a significant advantage for cancer staging and treatment decisions. The sentinel lymph node could also help radiation oncologists to identify tumor drainage for each of their patients, leading to a more personalized radiotherapy, instead of a probabilistic irradiation based on delineation atlases. The aim is both to avoid recurrence in unexpected areas and to limit the volume of irradiated healthy tissues. The aim of our study is to evaluate the impact of sentinel lymph node mapping for radiation oncologists. This concept, relying on sentinel lymph node mapping for treatment planning, is known as lymph-flow-guided radiotherapy. We present an up-to-date narrative literature review showing the potential applications of the sentinel lymph node technique for radiotherapy, as well as the limits that need to be addressed before its routine usage.

The value of sentinel lymph-node biopsy in women with node-positive breast cancer at diagnosis and node-negative tumour after neoadjuvant therapy: a systematic review

PURPOSE

To conduct a systematic review to analyse the performance of the sentinel lymph-node biopsy (SLNB) in women with node-positive breast cancer at diagnosis and node-negative tumour after neoadjuvant therapy, compared to axillary lymph-node dissection.

METHODS

The more relevant databases were searched. Main outcomes were false-negative rate (FNR), sentinel lymph-node identification rate (SLNIR), negative predictive value (NPV), and accuracy. We conducted meta-analyses when appropriate.

RESULTS

Twenty studies were included. The pooled FNR was 0.14 (95% CI 0.11-0.17), the pooled SLNIR was 0.89 (95% CI 0.86-0.92), NPV was 0.83 (95% CI 0.79-0.87), and summary accuracy was 0.92 (95% CI 0.90-0.94). SLNB performed better when more than one node was removed and double mapping was used.

CONCLUSIONS

SLNB can be performed in women with a node-negative tumour after neoadjuvant therapy. It has a better performance when used with previous marking of the affected node and with double tracer.

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 value of sentinel lymph-node biopsy after neoadjuvant therapy: an overview

PURPOSE

We conducted a systematic review to analyse the performance of the sentinel lymph-node biopsy (SLNB) after the neoadjuvant chemotherapy, compared to axillary lymph-node dissection, in terms of false-negative rate (FNR) and sentinel lymph-node identification rate (SLNIR), sensitivity, negative predictive value (NPV), need for axillary lymph-node dissection (ALND), morbidity, preferences, and costs.

METHODS

MEDLINE, Embase, Scopus, and The Cochrane Library were searched. We assessed the quality of the included systematic reviews using AMSTAR2 tool, and estimated the degree of overlapping of the individual studies on the included reviews.

RESULTS

Six systematic reviews with variable quality were selected. We observed a very high overlapping degree across the included reviews. The FNR and the SLNIR were quite consistent (FNR 13-14%; SLNIR ~ 90% or higher). In women with initially clinically node-negative breast cancer, the FNR was better (6%), with similar SLNIR (96%). The included reviews did not consider the other prespecified outcomes.

CONCLUSIONS

It would be reasonable to suggest performing an SLNB in patients treated with NACT, adjusting the procedure to the previous marking of the affected lymph node, using double tracer, and biopsy of at least three sentinel lymph nodes. More well-designed research is needed. PROSPERO registration number: CRD42020114403.