Molecular Imaging In Oncology: Tools for Early Cancer Detection, Personalized Therapy, and Guiding Drug Development

Molecular imaging has long been advertised as the key to early detection and personalizing treatment strategies in cancer management. The idea is that molecular contrast has the potential to detect microscopic tumor lesions on a macroscopic scale for whole body screening, and by understanding the molecular environment of an individual’s cancer, the optimal molecular targeted therapies can be tailored to that patient to provide the best chance of treatment success. Yet despite over 60 years of effort in the area, there has been no widespread adoption of any cancer-targeted imaging agents to date, owing largely to the fact that physiological variability amongst and between individual tumors can substantially obscure the relationship between cancer targeted imaging agent uptake and retention and the true expression of the cancer biomarkers that the imaging agent is targeted to. This presentation will focus on novel “paired-agent” molecular imaging approaches that provide the first means of directly quantifying agent-biomarker binding and biomarker concentrations in vivo. There will be a particular focus on detection of cancer metastasis, and improving cancer identification during tumor resection surgery.

Figure 1. Validation and applications of paired-agent fluorescent imaging. (a) Validation of ability to quantify cell surface receptor concentration by means of binding potential (BP) calculation in various tumor lines. (b) Demonstration that the paired-agent approach can account for significant nonspecific uptake even in organs of filtration like the kidney (Untar. = untargeted agent uptake image, Tar. = targeted agent uptake image, DT = dual-tag image). (c) Demonstration that paired-agent imaging can work in the face of substantial fluorescence absorption by melanin in melanomas. (d) Demonstration that microscopic levels of tumor burden can be detected by paired-agent methodology in tumor draining lymph nodes.