⁶⁸Ga-BBN-RGD PET/CT for GRPR and Integrin α_vβ₃ Imaging in Patients with Breast Cancer

Abstract

Purpose: This study was to assess a gastrin-releasing peptide receptor (GRPR) and integrin v3 dual targeting tracer 68 Ga-BBN-RGD for positron emission tomography (PET)/computed tomography (CT) imaging of breast cancer and metastasis. Materials and Methods: Twenty-two female patients were recruited either with suspected breast cancer on screening mammography (n = 16) or underwent breast cancer radical mastectomy (n = 6). All the 22 patients underwent PET/CT at 30-45 min after intravenous injection of 68 Ga-BBN-RGD. Eleven out of 22 patients also accepted 68 Ga-BBN PET/CT within 2 weeks for comparison. A final diagnosis was made based on the histopathologic examination of surgical excision or biopsy. Results: Both the primary cancer and metastases showed positive 68 Ga-BBN-RGD accumulation. The T/B ratios of 68 Ga-BBN-RGD accumulation were 2.10 to 9.44 in primary cancer and 1.10 to 3.71 in axillary lymph node metastasis, 3.80 to 10.7 in distant lymph nodes, 2.70 to 5.35 in lung metastasis and 3.17 to 22.8 in bone metastasis, respectively. For primary lesions, the SUVmax from 68 Ga-BBN-RGD PET in ER positive group was higher than that in ER negative group (P < 0.01). For both primary and metastatic lesions, SUVmean quantified from 68 Ga-BBN-RGD PET correlated well with both GRPR expression and integrin v3 expression.