Breast Cancer Treatment in the Era of Molecular Imaging

Abstract

Molecular imaging employs molecularly targeted probes to visualize and often quantify distinct disease-specific markers and pathways. Modalities like intravital confocal or multiphoton microscopy, near-infrared fluorescence combined with endoscopy, surface reflectance imaging, or fluorescence-mediated tomography, and radionuclide imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are increasingly used for small animal high-throughput screening, drug development and testing, and monitoring gene therapy experiments. In the clinical treatment of breast cancer, PET and SPECT as well as magnetic resonance-based molecular imaging are already established for the staging of distant disease and intrathoracic nodal status, for patient selection regarding receptor-directed treatments, and to gain early information about treatment efficacy. In the near future, reporter gene imaging during gene therapy and further spatial and qualitative characterization of the disease can become clinically possible with radionuclide and optical methods. Ultimately, it may be expected that every level of breast cancer treatment will be affected by molecular imaging, including screening.

Fig. 1

Micro-PET image of a mouse injected with 26?? of a ⁶⁴Cu-labelled anti-CEA minibody. Note the uptake in the CEA-positive tumor in the left shoulder (arrow), while no significant uptake occurs in the CEA-negative control tumor in the right shoulder (arrowhead). Unspe-cific uptake occurs in the liver. Adapted, with permission, from [53].

Fig. 2

In vivo mouse colonoscopy. In the first row, normal colon is shown. Neither in the NIR channel nor by ratio imaging a signal is detected. Second row, small APC^Min/+ adenoma, 3rd row, large APC^Min/+ adenoma, 4th row, invasive cancer. The NIR channel shows constantly areas of high signal intensity and high signal-to-background ratio corresponding to the areas of neoplasia. Ratio imaging shows moderately elevated values for small adenoma with moderate dysplasia, markedly elevated values for large adenoma with severe dysplasia, and high values for invasive cancer. The corresponding H and E sections demonstrate adenomatous formations with moderate or high dysplasia and tumoral invasion of the muscular layer. Adapted, with permission, from [21].

Fig. 3

Maximum-intensity projection of ans FDG-PET scan with extensive left pleural involvement A before and B after 1 dose of fulvestrant, with resolved pleural uptake. Note unspecific cardiac uptake (arrow). Adapted, with permission, from [4].