Comparison of [ 99m Tc]3PRGD 2 Imaging and [ 18 F]FDG PET/CT in Breast Cancer and Expression of Integrin α v β 3 in Breast Cancer Vascular Endothelial Cells.

PURPOSE: This study aimed to investigate the value of 99m technetium-three polyethylene glycol spacers-arginine-glycine-aspartic acid ([99m Tc]3PRGD2 ) imaging in diagnosis and staging of breast cancer compared with 2-deoxy-2-[18 F]fluoro-D-glucose ([18 F]FDG) imaging, and to explore the expression of integrin αv β3 in tumor vascular endothelial cells.

PROCEDURES: Forty-two women with suspected breast cancer underwent both [99m Tc]3PRGD2 imaging and [18 F]FDG imaging. Visual analysis was used to assess primary breast lesion, axillary lymph node, and distant metastasis. The tumor-blood (T/B) ratios from [99m Tc]3PRGD2 imaging and the maximum standardized uptake value (SUVmax) from [18 F]FDG imaging were analyzed for breast lesions. Integrin αv β3 was analyzed through immunohistochemistry.

RESULTS: Forty-five breast lesions were found (malignant, n = 38; benign, n = 7). The sensitivity, specificity, and accuracy of [99m Tc]3PRGD2 and [18 F]FDG imaging in visual analysis for the breast lesion were 97.4, 87.5, and 95.6 % and 97.4, 71.4, and 93.3 %, respectively (P > 0.05). For semi-quantitative analysis, no significant difference of the area under the curves (AUC) was found in the imaging using the two radiopharmaceuticals (0.880 and 0.955; Z = 0.88, P > 0.05). The sensitivity, specificity, and accuracy for axillary lymph node metastasis with [99m Tc]3PRGD2 and [18 F]FDG were 78.05, 99.36, and 94.92 % and 85.37, 98.72, and 95.64 %, respectively (P > 0.05). Nine patients with distant metastases were all detected with the two radiopharmaceuticals. The expression of integrin αv β3 was correlated with [99m Tc]3PRGD2 uptake (r = 0.582, P = 0.001), which were significantly higher in the HER2-positive and stage III-IV patients (P < 0.05).

CONCLUSIONS: The prospective study demonstrated that [99m Tc]3PRGD2 imaging seems to be valuable for diagnosis of breast cancer and its staging. It may be less sensitive for detecting small lymph node metastatic lesions when compared with [18 F]FDG imaging. Integrin αv β3 in tumor microvessels was associated with the breast cancer subtype and its staging.