Purpose: To investigate the diagnostic performance of 3'-deoxy-3'-[(18)F]fluorothymidine ((18)F-FLT) PET in women with suspicious breast findings on conventional imaging (mammography and breast ultrasound).
Methods: Twenty-eight women with suspicious findings on conventional imaging were enrolled. A whole-body PET/CT in the supine position (first PET) was performed 60 min after intravenous injection of 0.07 mCi/kg (18)F-FLT, followed by a regional PET of the breast in the prone position (second PET). For each lesion, the SUVmax of the first PET (SUV1) and second PET (SUV2) were measured. For the receiver operating characteristic (ROC) analysis of the diagnostic parameters, of the cutoff points with sensitivities >90 %, we chose the one with highest specificity as the optimal cutoff point to obtain the corresponding sensitivity and specificity.
Results: A total of 34 breast lesions (21 benign, 13 malignant) were analyzed. The SUV1 and SUV2 of the malignant lesions (median values 4.6 vs. 4.4, respectively) were higher than those of the benign lesions that had medians of 1.2 and 1.0, respectively (P = 0.0001). The area under the ROC curve (AUC) of SUV1 (0.905) showed no significant difference from that of SUV2 (0.912) (P = 0.77). The sensitivity and specificity using SUV1 = 1.24 as cutoff were 92.3 and 52.4 %, and those using SUV2 = 1.5 as cutoff were 92.3 and 66.7 %, respectively.
Conclusion: (18)F-FLT PET showed acceptable diagnostic performance for suspicious breast findings on conventional imaging, and SUV2 showed higher specificity than SUV1.