More than 1.5 million people are estimated to receive a cancer diagnosis in 2017 in the United States, according to recent statistics from the American Cancer Society.1 Fortunately, science and technology have made great strides in the management of the disease, with fewer mortality incidences occurring now than ever before. Targeted approaches to cancer treatment, including radiation and inhibitor agents, have seen success in improving survival in cancer patients.2,3 Imaging techniques have paved the way in helping many targeted therapies achieve high efficacy rates.
HER3 and imaging in cancer research
Human epidermal growth factor receptor 3 (HER3), a protein found in the ERBB3 gene, is a receptor that is sometimes overexpressed in various forms of cancer. The biomarkers for assessing HER3 status are few, and the lack of these markers may prevent the selection of appropriate therapies. When found in abundance in cancer cells, HER3 can prevent therapy success.4
The use of imaging of HER3 in research as well as clinical practice may determine receptor overexpression. Additionally, imaging may also assist in stratifying a patient’s risk status and determine whether or not they would require anti-HER3 therapy.
Essentially, determining overexpression of HER3 receptors via molecular imaging may help evaluate a patient’s resistance to therapy. Concurrently, clinicians may use these imaging results to monitor a patient’s response to medical intervention.
Positron emission tomography (PET) is one imaging approach that provides high resolution and high sensitivity. Combined with single photon emission computed tomography (SPECT) imaging, PET images can be enhanced at the molecular level.
Study uses Albira Si to evaluate HER3 receptors in mice
A study by Pieve et al. published in Bioconjugate Chemistry examined the development of high target affinity PET probes for imaging HER3 in a female mice model and also evaluated two strategies for radiolabeling the HER3 affibody molecule for targeting.5
One of the strategies involved using the Albira Si, a combined PET SPECT molecular imaging system.6 Utilization of a combined imaging system with CT can not only provide anatomical landmarking, it can also help researchers evaluate modifications related to disease progression.7
Using the Albira Si, researchers were able to determine that [18F]AlF-NOTA-ZHER3:8698 may be an effective HER3 imaging agent. Only with instrumentation that allowed a molecular view to the extent provided by Albira Si were the researchers able to perform the in vivo experiment safely and efficiently.
Bruker’s Albira Si—SiPM-based PET
Imaging of HER3 can help researchers determine an appropriate therapeutic target and provide an individualized approach to therapy. Additionally, high-quality molecular imaging can help organize patients into specific risk categories, assisting in developing a form of care that will consider potential treatment resistance.
The Albira Si, a PET/SPECT/CT imaging system, may help make this possible in the clinical research setting. This in vivo imaging technology can help in gaining knowledge related to underlying biological processes, gene expression, biodistribution, and pharmacokinetics and pharmacodynamics of new drugs. Albira Si is the first SiPM-based PET, providing Full Field of View Accuracy (FFA) and dual cardiac/pulmonary PET and SPECT gated imaging.
1. Siegel RL, Miller KD, Jemal A. Cancer Statistics, 2017. CA Cancer J Clin. 2017 Jan;67(1):7-30.
2. ASTRO. Advances in radiation therapy have improved survival rates for early stage lung cancer patients. https://www.astro.org/News-and-Publications/News-and-Media-Center/News-Releases/2016/Advances-in-radiation-therapy-have-improved-survival-rates-for-early-stage-lung-cancer-patients/. Published September 25, 2016.
3. Gross S, Rahal R, Stransky N, Lengauer C, Hoeflich KP. Targeting cancer with kinase inhibitors. J Clin Invest. 2015;125(5):1780-1789.
4. Rosestedt M, Andersson KG, Mitran B, et al. Affibody-mediated PET imaging of HER3 expression in malignant tumours. Sci Rep. 2015;5:15226.
5. Pieve CD, Allott L, Martins CD, et al. Efficient [18F]AlF Radiolabeling of ZHER3:8698 Affibody Molecule for Imaging of HER3 Positive Tumors. Bioconjugate Chemistry. 2016;27(8):1839–1849.
6. AlbiraSi. Bruker. https://www.bruker.com/products/preclinical-imaging/pet-spect-ct/albirasi/overview.html.
7. Davison CA, Chapman SE, Sasser TA, et al. Multimodal optical, X-ray CT, and SPECT imaging of a mouse model of breast cancer lung metastasis. Curr Mol Med. 2013;13(3):368-376.