Sentinel lymph node mapping in colorectal cancers with radioactive tracer; is it an efficient method?

Area of Science:

• Oncology
• Surgical Pathology
• Nuclear Medicine

Background:

• Sentinel lymph nodes (SLNs) are susceptible to tumoral invasion in various cancers, including colorectal cancer.
• SLN identification is crucial for accurate pathological staging in colorectal cancer patients.
• Conventional pathological examination techniques for SLNs can be enhanced by radioactive tracer methods.

Purpose of the Study:

• To investigate the efficiency of radioactive tracer-guided sentinel lymph node (SLN) identification in colorectal cancer.
• To compare the pathological findings of SLNs and non-SLNs using a standardized conventional method.
• To assess the sensitivity, accuracy, and upstaging rate of SLN mapping in colorectal cancer.

Main Methods:

• A cross-sectional, single-center study involving 100 patients with colorectal cancer.
• Radioactive tracer was employed for SLN detection.
• Conventional pathological methods were used for examining both SLNs and non-SLNs.

Main Results:

• Sentinel lymph nodes (SLNs) were successfully detected in 89% of patients.
• The study reported a sensitivity of 43.75% and an accuracy of 78.65% for SLN mapping.
• Ten cases of upstaging and nine false negatives were observed, particularly in patients with T4 lower rectal cancer.

Conclusions:

• The conventional method for SLN biopsy in colorectal cancer demonstrated lower sensitivity and accuracy compared to similar studies.
• The observed upstaging rate was also suboptimal, suggesting limitations in the current approach.
• Recommendations include exploring intensive SLN biopsy techniques for both SLNs and non-SLNs in future research.