Role of Molecular Imaging in Oncology

Abstract

Molecular Imaging (MI) is an emerging technology for the early detection of disease,
staging of the disease, and for monitoring response to therapy. It also offers a non-invasive
method to detect in vivo biological functions and processes at a molecular level. The use of MI
requires careful selection of targeting molecules which are expressed differentially in diseased
vs. healthy cells to interrogate the cell microenvironment. Targeting molecules for MI could
consist of small molecules, single amino acid units, low molecular weight peptides, antibodies
or antibody fragments. Over the years, a large number of small molecular weight imaging
probes have been developed to target different molecular pathways using Positron Emission
Tomography (PET) and Single Photon Emission Computed Tomography (SPECT). The use
of high molecular weight probes such as radioactive antibodies (Ab) is also equally attractive.
While a major effort is placed on developing radioactive probes for PET and SPECT imaging,
an intense effort is being focused on enhancing the utility of other MI modalities such as
nuclear Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS),
Computed Tomography (CT), optical imaging and ultrasound (US).