Intraoperative sentinel node detection improves nodal staging in invasive bladder cancer

Area of Science:

• Urology
• Surgical Oncology
• Nuclear Medicine

Background:

• Radical cystectomy with extended lymphadenectomy is standard for invasive bladder cancer.
• Accurate nodal staging is crucial for treatment planning and prognosis.
• Sentinel lymph node (SN) biopsy may improve staging accuracy.

Purpose of the Study:

• To evaluate intraoperative SN detection during radical cystectomy for invasive bladder cancer.
• To assess the feasibility and accuracy of SN identification using combined techniques.

Main Methods:

• 75 patients with invasive bladder cancer underwent radical cystectomy and extended lymphadenectomy.
• SNs were identified using preoperative lymphoscintigraphy, intraoperative dynamic lymphoscintigraphy, and blue dye.
• Isotope ((99m)Tc-nanocolloid) and Patent Blue dye were injected peritumorally.
• Ex vivo examination of excised nodes used a handheld gamma probe, serial sectioning, H&E staining, and immunohistochemistry.

Main Results:

• An SN was identified in 87% of patients (65/75).
• Of 32 lymph node-positive patients, 26 (81%) had a metastatic SN, resulting in a 19% false-negative rate.
• Micrometastases were found in SNs of 9 patients (14%), and radio-guided surgery identified additional SNs in 7 patients.

Conclusions:

• Intraoperative SN detection is feasible in invasive bladder cancer.
• The study demonstrated a 19% false-negative rate, highlighting areas for improvement.
• Combined techniques, including extended serial sectioning and immunohistochemistry, enhanced nodal staging accuracy in 25% of cases.