Sentinel Lymph Node Techniques in Urologic Oncology: Current Knowledge and Application

SIMPLE SUMMARY: Lymph node (LN) metastases are a significant concern in urological malignancies. However, current imaging techniques do not reliably detect micrometastases; thus, lymph node dissection (LND) remains the gold standard. Nevertheless, there is no established ideal LND template, leading to unnecessary invasive staging and the possibility of missing LN metastases located outside the standard template. The sentinel lymph node (SLN) concept has been proposed to address this issue, but its application in uro-oncology is still mostly experimental. Nevertheless, new techniques may improve its potential. This review aims to discuss the current and future role of the SLN procedure in managing urological malignancies. ABSTRACT: Lymph node (LN) metastases have a significant negative impact on the prognosis of urological malignancies. Unfortunately, current imaging modalities are insufficient when it comes to detecting micrometastases; thus, surgical LN removal is commonly used. However, there is still no established ideal lymph node dissection (LND) template, leading to unnecessary invasive staging and the possibility of missing LN metastases located outside the standard template. To address this issue, the sentinel lymph node (SLN) concept has been proposed. This technique involves identifying and removing the first group of draining LNs, which can accurately stage cancer. While successful in breast cancer and melanoma, the SLN technique in urologic oncology is still considered experimental due to high false-negative rates and lack of data in prostate, bladder, and kidney cancer. Nevertheless, the development of new tracers, imaging modalities, and surgical techniques may improve the potential of the SLN procedures in urological oncology. In this review, we aim to discuss the current knowledge and future contributions of the SLN procedure in the management of urological malignancies.