[The role of preoperative investigation with 18-FDG-PET/CT in primary operable breast cancer].

Introduction: The widespread use of PET/CT has a potential to change oncological diagnosis fundamentally. In our study we intended to clarify if preoperative PET/CT was able to assess axillary lymph node status, and the potential of these to modify preliminary treatment plans based on conventional diagnostic methods.

Patients And Methods: We carried out 18-FDG PET/CT before elective surgery in 52 primary operable breast cancer patients between February 2008 and February 2009 at the DEOEC Clinical Department of Surgery. Total body imaging was performed in all cases; scans were evaluated by two specialists first visually, then semi-quantitatively based on body mass-corrected lesion suvmax values. The assessments were compared with axillary ultrasound and final histological diagnosis.

Results: Two patients were excluded from the study due to failure to report for further treatment. Based on the results obtained from the remaining 50 patients, PET/CT showed a sensitivity of 80%, a specificity of 100%, positive and negative predictive values of 100% and 84.6% respectively for detecting axillary lymph node metastases. The same figures for axillary ultrasound, in respective order, were 30%, 81.8%, 60% and 56.2%. Prompted by the PET/CT results, we modified 9 patients' (18%) preliminary, conventional diagnosis-based treatment schemes.

Conclusions: In case of a positive axillary PET/CT, it is unnecessary to perform SNB--axillary block dissection is called for with no further deliberation. Preoperative PET/CT can facilitate patient selection as regards possible benefit from neoadjuvant therapy. Preoperative PET/CT has a potential to modify the original management plan in about 15 to 20%. In case of a negative PET/CT scan, further studies are necessary to be able to spare the axilla from surgical intervention with confidence.