Breast cancer: variables affecting sentinel lymph node visualization at preoperative lymphoscintigraphy.

Area of Science:

• Oncology
• Nuclear Medicine
• Surgical Pathology

Background:

• Sentinel lymph node biopsy (SLNB) is crucial for breast cancer staging.
• Lymphoscintigraphy is a key preoperative tool for identifying sentinel lymph nodes (SLNs).
• Understanding factors influencing SLN visualization is important for surgical planning.

Purpose of the Study:

• To compare patients with visualized versus nonvisualized SLNs.
• To identify variables affecting SLN visualization during preoperative lymphoscintigraphy.
• To analyze nodal drainage basins in relation to breast tumor location.

Main Methods:

• 136 breast cancer patients underwent preoperative lymphoscintigraphy before SLNB.
• Comparison of visualized and nonvisualized SLN groups based on patient and tumor characteristics, and procedural details.
• Analysis of SLN drainage basins in visualized cases.

Main Results:

• 99 patients had visualized SLNs, 37 had nonvisualized SLNs.
• No significant differences in tumor characteristics or biopsy methods between groups.
• Older age was associated with nonvisualized SLNs; 81% of nonvisualized SLNs were identified during surgery.
• Internal mammary drainage occurred in 46% of tumors located in the outer breast quadrant.

Conclusions:

• Age, surgical identification method, and SLN visualization status differed between groups.
• Nonvisualized SLNs do not exclude the possibility of axillary metastasis.
• Blue dye may enhance SLN detection in older patients with nonvisualized SLNs compared to radiocolloid alone.