Scientists from Dartmouth the Geisel School of Medicine have developed a new fluorescence imaging technique that can more accurately identify receptors for targeted cancer therapies without tissue biopsy. This study was published in Cancer Research.

Protein overexpression is a hallmark of certain cancers and is used in clinical oncology to personalize treatment through tumor detection, molecular therapies, and therapeutic monitoring. Protein expression is currently measured through a total protein analysis of tumor tissue.

In this study, researchers developed a dual-tracer in vivo receptor concentration imaging (RCI) technique that involves the simultaneous injection of both a targeted and non-targeted imaging agent. They found that the protein expression determined by RCI strongly correlated to that determined by tissue analysis. They also found that commonly used techniques of measuring protein expression, such as western blots of flow cytometry, did not correlate to the RCI values, and in fact over-predicted the number of receptors available for therapeutic or diagnostic targeting.

Accurately determining the population of protein receptors in a tumor available for targeting by molecular therapies or diagnostic imaging agents can greatly impact oncology patient outcomes. This new technique allows scientists to accurately determine the amount of protein receptors available for binding a drug without invasive biopsy. The next step of the study will be to look at tumors on a microscopic level in order to correlate receptor expression to distinct physiological features such as cellular viability, cellular type, vascularity, and overall tumor architecture.

Reference:Samkoe K S, Tichauer K M, Gunn J R, et al. Quantitative in vivo immunohistochemistry of epidermal growth factor receptor using a receptor concentration imaging approach[J]. Cancer research, 2014: canres. 0141.2014.