PET/Fluorescence Imaging: An Opportunity to Integrate Diagnosis with Surgery

Abstract

Over the last a few decades, the field of imaging science witnessed exponential growth on many imaging techniques including Computed Tomography (CT), Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), bioluminescence, fluorescence, and Magnetic Resonance Imaging (MRI) [1,2]. With the ability to image specific biological pathways at the molecular and cellular level in vivo [3], molecular imaging techniques are widely used in diagnostic and therapeutic field. It also successfully accelerates the drug discovery and development process, especially for personalized medicine development. Generally, each molecular imaging technique has its own advantages and limitations in spatial and temporal resolution, depth penetration, sensitivity and cost [4]. It is possible that synergistic effect could be obtained by the fusion of two or more in vivo imaging techniques [5-7]. In particular, PET is a powerful imaging technique closely related to clinical translation in oncology. PET could provide critical in vivo information on the distribution of radio labeled biomolecules, which would help a noninvasive cancer diagnosis [8-10]. In contrast, fluorescence imaging has been demonstrated to be a superior method for intra operative tumor detection [11-14]. In clinical practice, tumors were more efficiently detected using the tumor-specific intra operative fluorescence imaging than with the conventional visual inspection. Since both PET and optical imaging have unique features for clinical applications, PET/fluorescence dual modality imaging might greatly benefit the patients because the lesion could be located using noninvasive PET scans (diagnosis), and the optical motif would allow surgeons to identify the PET-detected lesions or smaller metastasis in intra operative image-guided surgery (therapy). Clearly, general methods are greatly needed for simple and efficient construction of PET/fluorescence dual modality probes.