[en] Objective: To evaluate the value of ⁹⁹Tc^m-3PRGD2 integrin receptor imaging in qualitative diagnosis of breast cancer and then compare this technique with mammography. Methods: A total of 84 female patients with established breast lesions were recruited. All patients were examined using ⁹⁹Tc^m-3PRGD2 integrin receptor imaging and mammography. Diagnosis of breast(especially dense breast) lesion by using these two techniques was analyzed and compared with postoperative pathology as the gold standard. T test and χ² test were used for data statistical analysis by using SPSS22.0 software. Results: The diagnostic efficiency of SPECT/CT imaging was higher than that of whole-body imaging. The intake rates of T_max, T_mean, T_mean/B, and T_max/B were significantly higher in breast cancer than in benign nodules(t = 2.09∼3.19, all P < 0.05), and their difference in intake of T_max/B was obvious(t = 3.19, P < 0.01). The difference between 2 and 4 h imaging was not significant(t = 0.63∼1.25, all P > 0.05). The sensitivity of SPECT/CT in diagnosis of breast cancer was more than 95.0%, which could be increased to 98.4% when this technique was combined with mammography. For dense mammary gland, the sensitivity, specificity, and accuracy of ⁹⁹Tc^m-3PRGD2 SPECT/CT and mammography were 95.2%, 83.3%, and 91.7% and 78.6%, 76.2%, and 77.8%, respectively, ⁹⁹Tc^m-3PRGD2 SPECT/CT had a higher accuracy(χ² = 4.341, P < 0.05). Conclusions: ⁹⁹Tc^m-3PRGD2 SPECT/CT had high sensitivity and was a useful complement to mammography. This technique demonstrated a higher diagnostic value than mammography for qualitative diagnosis of dense mammary gland. (authors)