BLADDER cancer is among the top ten most prevalent cancers worldwide, with a five-year survival rate of only 58% following radical cystectomy (RC). A significant factor affecting prognosis is lymph node metastasis, occurring in up to 25% of patients with muscle-invasive bladder cancer. Pelvic lymph node dissection (PLND), performed alongside RC, is crucial for improving survival rates, accurately staging the disease, and determining treatment strategies. However, traditional PLND carries risks such as damage to adjacent tissues and incomplete node removal.
Recent advancements in near-infrared fluorescence imaging have revolutionised lymph node tracing in cancers such as breast and penile cancers. Building on this, researchers developed a novel method for identifying pelvic lymph nodes in bladder cancer using indocyanine green (ICG). By injecting ICG intradermally into the lower limbs and perineum, the lymphatic drainage system is traced, allowing precise localisation and identification of pelvic lymph nodes during surgery. This approach addresses key challenges, including minimising unnecessary tissue removal, reducing surgical complications, and improving procedural efficiency.
The study evaluated 54 RC+PLND patients, comparing outcomes between those undergoing standard surgery and those guided by ICG fluorescence imaging. Results showed that ICG-guided surgery significantly improved lymph node localisation accuracy and reduced operating time, without compromising the total number of nodes removed. Importantly, stable fluorescence labelling of lymph nodes persisted for up to 4.5 hours post-injection, with no evidence of contamination or ineffective diffusion.
The findings also highlighted distinct lymphatic pathways from lower limbs and perineum to the pelvic cavity, offering insights into metastatic patterns. Notably, fluorescence imaging effectively labelled lymph nodes such as the Cloquet, obturator, and external iliac nodes – key sites for bladder cancer metastasis.
This groundbreaking approach offers a promising solution to longstanding challenges in PLND. By enhancing the precision and efficiency of lymph node removal, fluorescence-guided surgery has the potential to improve survival outcomes and set new standards in bladder cancer treatment. Further clinical trials are needed to refine and standardise this innovative technique.
Katie Wright, EMJ
Reference
Wei Y et al. Fluorescence imaging-guided pelvic lymph node localization and resection of bladder cancer after intracutaneous injection of indocyanine green into the lower limbs and perineum. UroPrecision. 2024;2:109-17.
