Fluorodeoxyglucose positron emission tomography with sentinel lymph node biopsy for evaluation of axillary involvement in breast cancer

Background: This study analysed the value of [F-18]fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting axillary lymph node involvement in women with breast cancer. Methods: In the first 150 women in this prospective study, axillary lymph node dissection (ALND) was performed regardless of the PET results. In a second group (125 women) FDG-PET was complemented with sentinel lymph node biopsy (SLNB) only in those who did not have pathological axillary uptake. Results: The sensitivity and specificity of FDG-PET in detecting axillary involvement was 84.5 and 98.5 percent respectively in the whole series of 275 patients, with two false-positive and 22 false-negative results. False-negative results were associated with some intrinsic tumour characteristics. In 21 women, PET revealed pathological uptake, suggesting involvement of the internal mammary lymph node chain. Whole-body PET identified a second synchronous tumour in five asymptomatic patients and haematogenous metastases in two patients. Conclusion: The high positive predictive value of PET (98.4 per cent) suggests that FDG uptake in the axilla could be an indication for full ALND without previous SLNB.