[METHODOLOGIC PROBLEMS OF SENTINEL LYMPH NODE BIOPSY IN PATIENTS WITH BREAST CANCER]

Area of Science:

• Oncology
• Radiology
• Nuclear Medicine

Background:

• Accurate staging of breast cancer requires assessment of axillary lymph node status.
• Sentinel lymph node biopsy is a standard procedure, often complemented by imaging techniques.
• Evaluating the effectiveness of different diagnostic models and radiopharmaceutical characteristics is crucial for improving staging accuracy.

Purpose of the Study:

• To compare two diagnostic models for axillary lymph node metastasis detection using ultrasound and planar scintigraphy.
• To evaluate the impact of radiocolloid particle size on sentinel lymph node imaging and detection.
• To determine the sensitivity, specificity, and accuracy of combined imaging modalities in staging breast cancer.

Main Methods:

• Retrospective analysis of 168 breast cancer patients undergoing axillary dissection or sentinel lymph node biopsy.
• Utilized ultrasound and planar scintigraphy for imaging breast and regional lymph drainage zones.
• Compared diagnostic models based on scintigraphy and ultrasound findings, and analyzed radiocolloid particle size (≤100 nm vs. 200-1000 nm).

Main Results:

• The first diagnostic model (any positive finding) showed 82.7% sensitivity, 67.7% specificity, and 74.4% accuracy.
• The second diagnostic model (simultaneous positive findings) achieved 94.6% specificity but only 56% sensitivity.
• Radiocolloids with particle diameters up to 100 nm demonstrated rapid transport, high sentinel lymph node accumulation, and near 100% visualization.

Conclusions:

• Diagnostic model selection impacts sensitivity and specificity in axillary lymph node staging.
• Smaller radiocolloid particles (≤100 nm) offer significant advantages for sentinel lymph node visualization and detection in breast cancer staging.
• Combined ultrasound and scintigraphy, particularly with optimized radiopharmaceuticals, can enhance the accuracy of regional lymph node assessment.