Vascular endothelial growth factor (VEGF)-A is overexpressed in most malignant and premalignant breast lesions. VEGF-A can be visualized noninvasively with PET imaging and using the tracer 89 Zr-labeled bevacizumab. In this clinical feasibility study, we assessed whether VEGF-A in primary breast cancer can be visualized by 89 Zr-bevacizumab PET. Methods: Before surgery, breast cancer patients underwent a PET/CT scan of the breasts and axillary regions 4 d after intravenous administration of 37 MBq of 89 Zr-bevacizumab per 5 mg. PET images were compared with standard imaging modalities. 89 Zr-bevacizumab uptake was quantified as the maximum standardized uptake value (SUV max ). VEGF-A levels in tumor and normal breast tissues were assessed with enzyme-linked immunosorbent assay. Data are presented as mean 6 SD. Results: Twenty-five of 26 breast tumors (mean size 6 SD, 25.1 6 19.8 mm; range, 4-80 mm) in 23 patients were visualized. SUV max was higher in tumors (1.85 6 1.22; range, 0.52-5.64) than in normal breasts (0.59 6 0.37; range, 0.27-1.69; P , 0.001). The only tumor not detected on PET was 10 mm in diameter. Lymph node metastases were present in 10 axillary regions; 4 could be detected with PET (SUV max , 2.66 6 2.03; range, 1.32-5.68). VEGF-A levels in the 17 assessable tumors were higher than in normal breast tissue in all cases (VEGF-A/mg protein, 184 6 169 pg vs. 10 6 21 pg; P 5 0.001), whereas 89 Zr-bevacizumab tumor uptake correlated with VEGF-A tumor levels (r 5 0.49). Conclusion: VEGF-A in primary breast cancer can be visualized by means of 89 Zr-bevacizumab PET.

Purpose: HSP90 chaperones have key client proteins that are involved in all hallmarks of breast cancer growth and progression. The primary aim of this clinical trial was to evaluate the feasibility of using 89 Zr-

Human epidermal growth factor receptor (HER)2 imaging with radiolabeled trastuzumab might support HER2-targeted therapy. It is, however, frequently questioned whether HER2 imaging is also possible during trastuzumab treatment as the receptor might be saturated. We studied the effect of trastuzumab treatment on 111In-trastuzumab uptake. Patients received trastuzumab weekly and paclitaxel once every 3 weeks. 111In-trastuzumab was injected on day 1 of cycle 1 and day 15 of cycle 4. Whole-body planar scintigraphy was acquired at different time points postinjection. Tumor uptake and organ distribution between the first and repeated scan series were calculated via residence times. Twenty-five tumor lesions in 12 patients were visualized on both scintigraphy series. Tumor uptake decreased (19.6%; p  =  .03). The residence times of normal organs remained similar except for the cardiac blood pool (+ 16.3%; p  =  .014). Trastuzumab treatment decreases tumor 111In-trastuzumab uptake around 20%. HER2 imaging is feasible during trastuzumab treatment.

No abstract

No abstract

No abstract

No abstract

No abstract