[The role of / 18FDG PET/CT for the initial staging and therapy in primary breast cancer].

PURPOSE

To evaluate the utility of / 18F-FDG PET/CT in the initial staging and predicting response to neoadjuvant chemotherapy ( NAC) for primary breast cancer.

METHODS

One hundred fourteen patients with primary breast cancer were preoperatively evaluated with PET/CT. The diagnostic value of PET/CT was compared in the final histopathology following surgery. Twenty patients also underwent PET/CT at baseline and after 4 and 8 courses of NAC. Changes (deltaSUV)in the maximum standard uptake value (SUVmax) between baseline study and after 4 or 8 courses of NAC were compared with the pathological response.

RESULTS

In the detection of primary breast cancer, PET/CT was 80. 7% sensitive, and especially, less sensitive in the detection of tumor size less than 10mm (66. 7%), low tumor grade (61. 3%), and ductal carcinoma in situ (50%). For axillary staging, PET/CT was 51. 9% sensitive and 95. 3% specific; in particular, it was less sensitive for small (<10mm) axillary lymph nodes (29. 4%) and could not detect micrometastasis. A cut-off deltaSUV value of 91. 9% was determined between baseline and after 4 courses of NAC differentiated responders(pathological CR)and non-responders, with a sensitivity of 80%, and a specificity of 78. 6% (p=0. 038).

CONCLUSION

Although PET/CT may have limited diagnostic value for detecting primary tumor and axillary staging, it is a valuable modality for monitoring the response to therapy.