Optimal diagnostic criteria for lateral lymph node dissection using magnetic resonance imaging: a multicenter...

Area of Science:

• Oncology
• Surgical Oncology
• Diagnostic Imaging

Background:

• Lateral lymph node metastasis is a concern in rectal cancer treatment.
• Optimal indications for lateral lymph node dissection (LLND) remain undetermined.
• Magnetic resonance imaging (MRI) is explored for guiding LLND decisions.

Purpose of the Study:

• To establish optimal indications for LLND in rectal cancer patients.
• To develop diagnostic criteria for lateral lymph node metastasis using MRI.
• To improve patient selection for LLND.

Main Methods:

• Prospective registration of 209 rectal adenocarcinoma patients undergoing total mesorectal excision and LLND.
• One-by-one pathological confirmation of harvested lymph nodes against MRI.
• Establishment of diagnostic criteria for LLND based on MRI parameters of lateral lymph nodes.

Main Results:

• 31.1% of harvested lateral lymph nodes were visualized on MRI.
• Individual MRI parameters showed correlation but lacked sufficient sensitivity for metastasis discrimination.
• A combination of long axis and short/long ratio in MRI achieved 94.3% sensitivity and 40.2% specificity for lateral lymph node metastasis.

Conclusions:

• Novel MRI-based criteria for LLND in rectal cancer were established.
• These criteria demonstrate high sensitivity for detecting lateral lymph node metastasis.
• The developed criteria are expected to be clinically valuable for determining LLND indications.