Role of FDG PET-CT in evaluation of axillary lymph node involvement in T1T2N0 breast cancer in comparison with sentinel lymph node biopsy

Objectives Role of FDG PET-CT in evaluation of axillary lymph node involvement in T1T2N0 in comparison with sentinel lymph node biopsy

Methods 37 patients of proven breast cancer were included of T1T2N0 tumor clinically and by ultrasound scan. Patients with treated breast cancer or past history of breast surgery or T3T4 disease and uncontrolled diabetes mellitus were excluded from the study.Preoperative FDG PET-CT was done followed by Sentinel lymph node( SLN) biopsy with blue dye or combined technique. All nodes evaluated by H&E staining and sentinel node by Immunohistochemistry.

Results SLN was identified in 32 of 37 patients with an identification rate of 86.48%(32/37). Combined technique SLN identified in 6 of 6 patients(100%) and blue dye alone SLN identification rate was 83.8 % (26/31). 16 had axillary metastases,12 with macrometastases and 4 with micrometastases. In 32 patients in whom SLN was identified 8 had macro and 4 had micrometastases. 2 patients had axillary metastases in whom SLN was not identified. sensitivity of SLN was 85.7%(12/14) and false negative value of 14.3%(2/14). PET-CT has shown sensitivity, specificity, negative predictive value and positive predictive value of 56%, 90%, 73%, 81.8% respecticely.immunohistochemistry of SLN detected 4 patients with micrometastases upstaging by 11% ( 4/37)

Conclusions PET-CT has high specificity and positive predictive value. It has low sensitivity for detection of axillary node metastases,expensive and available at few centres. Immunohistochemistry of SLNs - upgraded axillary staging