The role of technetium-99m isotope in sentinel lymph node identification in gynecological cancers

Sentinel lymph node (SLN) identification plays a crucial role in the diagnosis and management of gynecological cancers, particularly in the context of lymph node metastases that often remain undetectable through standard imaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET). Therefore, surgical assessment of lymph nodes remains an essential component of diagnostic procedures. SLN biopsy enables the detection of small metastatic deposits while reducing the need for extensive lymphadenectomy and minimizing associated complications. Lymphoscintigraphy using technetium-99m (Tc-99m) is one of the most commonly applied techniques for lymphatic mapping and is considered the standard method for SLN identification. In clinical practice, Tc-99m is frequently combined with indocyanine green (ICG) or methylene blue (MB) to allow dual visualization. The dye method, despite its simplicity, has certain limitations, such as shorter retention time in lymph nodes and the risk of diffusion into capillaries, which may reduce detection efficiency. Lymphoscintigraphy with Tc-99m provides precise visualization of lymphatic drainage pathways and SLNs, contributing to a more accurate determination of cancer staging and reducing the number of unnecessary lymphadenectomies. The appropriate application of this technique lowers the risk of complications, such as lymphedema, while maintaining high diagnostic accuracy. This review summarizes current evidence on the clinical application of Tc-99m in SLN detection for gynecological cancers, analyzing both its advantages and the challenges related to its practical implementation. Additionally, it discusses the technical aspects of Tc-99m use and its role as a reliable tool for optimizing oncological outcomes.