Technical limitations of lymph node mapping in pancreatic cancer

Area of Science:

• Oncology
• Surgical Oncology
• Pathology

Background:

• Pancreatic cancer frequently involves lymphatic and peri-neural invasion, leading to poor loco-regional control.
• Radical pancreatico-duodenectomy offers improved loco-regional control but increases patient morbidity.
• Selective radical resection based on intra-operative pathological lymph node (LN) mapping is a potential strategy.

Purpose of the Study:

• To assess the technical feasibility of intra-operative sentinel lymph node (SLN) mapping in pancreatic cancer.
• To determine if SLN mapping can guide selective radical resection, potentially reducing morbidity.
• To evaluate the accuracy of methylene blue dye in identifying metastatic LNs in pancreatic cancer.

Main Methods:

• A feasibility study involving patients with suspected pancreatic cancer undergoing resection.
• Peri- and intra-tumoral injection of methylene blue dye to identify putative SLNs.
• Kausch-Whipple procedure or total pancreatectomy with radical LN dissection and histopathological evaluation.

Main Results:

• 14/16 patients underwent lymph node mapping, with a mean of 20 LNs harvested per patient.
• Methylene blue dye identified SLNs in 4/14 patients; none contained metastases.
• 10/14 patients had LN metastases, with common sites including stations 17A/B, 8A, and 6.

Conclusions:

• Sentinel lymph node mapping using methylene blue dye is not technically feasible in pancreatic cancer.
• The technique failed to reliably identify metastatic lymph nodes, precluding its use for selective surgery.
• Further research into alternative SLN mapping techniques may be warranted for pancreatic cancer management.