Photoacoustic imaging with an acoustic lens detects prostate cancer cells labeled with PSMA-targeting near-infrared dye-conjugates.

Vikram Dogra,Shalini Singh,Navalgund Rao,Bhargava Chinni,Hans Schmitthenner,Kent L Nastiuk,John J Krolewski

doi:10.1117/1.jbo.21.6.066019

Abstract

.There is an urgent need for sensitive and specific tools to accurately image early stage, organ-confined human prostate cancers to facilitate active surveillance and reduce unnecessary treatment. Recently, we developed an acoustic lens that enhances the sensitivity of photoacoustic imaging. Here, we report the use of this device in conjunction with two molecular imaging agents that specifically target the prostate-specific membrane antigen (PSMA) expressed on the tumor cell surface of most prostate cancers. We demonstrate successful imaging of phantoms containing cancer cells labeled with either of two different PSMA-targeting agents, the ribonucleic acid aptamer A10-3.2 and a urea-based peptidomimetic inhibitor, each linked to the near-infrared dye IRDye800CW. By specifically targeting cells with these agents linked to a dye chosen for optimal signal, we are able to discriminate prostate cancer cells that express PSMA.

Highlights

The clinical management of early stage, organ-confined prostate cancer (PrCa) is challenging
In order to improve depth penetration and image quality, exogenous chromophores can be employed as contrast agents as part of a targeted molecular imaging agents (TMIAs)
Using a laser tuned to the maximum excitation wavelength of the TMIA-chromophore, tumor detection can be greatly enhanced as these exogenous chromophores have absorptivity factors two- to three-orders of magnitude greater than those of endogenous agents such as Hb.[15]

Summary

Introduction

The clinical management of early stage, organ-confined prostate cancer (PrCa) is challenging. There is no reliable technology to identify the rare aggressive cancers among the mass of indolent screen-detected PrCa, which has led to frequent overtreatment by surgery or radiation. A lot of effort has been focused on the development of tissue or serum biomarkers to differentiate indolent from aggressive disease, but this has not yet yielded sensitive and specific clinical tools. The current clinical paradigm for screendetected PrCa is active surveillance[2,3] (AS): monitoring by serum PSA testing and serial prostate biopsies to determine the grade (Gleason score) and extent of tumor

Methods

Results

Conclusion