Diagnostic performance in detection of breast cancer with a dedicated breast PET scanner

Objectives The purpose of this study was to evaluate the diagnostic performance in the detection of breast cancer of dedicated breast PET (dbPET), compared with that of conventional whole-body PET/CT (WB-PET/CT).

Methods A total of 163 females with breast cancer underwent a WB-PET/CT scan, followed by breast scanning with dbPET. The diagnostic performance of each scanner was calculated on a patient basis, breast basis, and lesion basis, according to the final pathological diagnosis. In addition, for patients who had surgical resection without neoadjuvant treatment, we evaluated detectability, based on the pT-stage.

Results In the 163 patients, 195 cancer foci in 321 breasts were analyzed in this study. Among them, 26 patients had multiple lesions in one breast and 6 patients had bilateral breast cancers. Patient-based, breast-based, and lesion-based sensitivities of dbPET were 88%, 88%, and 85%, respectively, and they were 95%, 95%, and 91% after excluding lesions outside the field of view (FOV). Meanwhile, those of WB-PET/CT were 95%, 94%, and 89%, respectively. The breast-based specificity was 95%. Of the 163 patients, 94 lesions in 82 patients were included in the evaluation according to pT-stage. Five lesions outside the FOV were excluded from the analysis. The sensitivities of dbPET and WB-PET/CT were 50% and 50% in pT1a, 79% and 57% in pT1b, 97% and 97% in pT1c, 100% and 95% in pT2, 100% and 100% in pT3, and 75% and 83% in pTis, respectively.

Conclusions The diagnostic performances were almost comparable between the two scanners; however, the detection rate for T1b lesions was slightly higher in dbPET, although the difference was not significant.