In the future, photoacoustic imaging (PAI) may help clinicians more accurately monitor patients with prostate cancer, and better distinguish early stage tumors from advanced cancers, according to study results from researchers in Roswell Park Cancer Institute, Buffalo, NY, published in the June 2016 issue of the Journal of Biomedical Optics.
In patients with nonaggressive prostate cancer, clinicians must work to reduce unnecessary treatments via active surveillance, but need more sensitive and specific tools to accurately image early-stage, organ-confined tumors from advanced cancers. These researchers have developed an acoustic lens that effectively enhances the sensitivity of photoacoustic imaging.
“This proof-of-concept study demonstrates that this technology may allow for real-time monitoring of prostate cancer in patients during the course of active surveillance. For patients with more aggressive disease, the technology could offer more precise targeting of biopsies to confirm the need for definitive therapy,” says senior author Kent Nastiuk, PhD, assistant professor, Cancer Genetics and Genitourinary Cancers, Roswell Park.
“This technology offers the potential to confirm the initial prostate cancer diagnosis, guide biopsies, and monitor tumor volume — which is currently not measureable — for improved case management and treatment decision-making,” he added.
Dr. Nastiuk’s co-authors include scientists from Roswell Park Cancer Institute, the University of Rochester, and the Rochester Institute of Technology.
In this study, they report their proof-of-concept results using this PAI in tandem with two molecular imaging agents designed to specifically target prostate-specific membrane antigen (PSMA), which is expressed on the tumor cell surface of most prostate cancers. These two agents were ribonucleic acid aptamer A10-3.2 and a urea-based peptidomimetic inhibitor, which were each linked to the near-infrared dye IRDye800CW, and chosen to deliver optimal signaling.
Dr. Nastiuk and colleagues were able to successfully identify those prostate cancer cells that expressed PSMA via the use of ultrasound technology to ‘listen’ to how the IRDye800Cw dye reacted to light waves when attached to PSMA as targeted. In the absence of PSMA with which to bind, the absence of IRDye800CW caused ‘silence.’ Thus, researchers were able to accurately distinguish between cells with and without PSMA.
“This technology offers the potential to confirm the initial prostate cancer diagnosis, guide biopsies, and monitor tumor volume — which is currently not measureable — for improved case management and treatment decision-making,” concluded Dr. Nastiuk.
This work was supported by the National Cancer Institute (project nos. R01CA151753, R15CA192148 and P30CA16056), National Institute of Biomedical Imaging and Bioengineering (project no. R15EB019726), National Institute of Arthritis and Musculoskeletal and Skin Diseases (project no. P30AR061307), the U.S. Department of Defense (award no. W81XWH-14-1-0242) and the Sonya A. Sinicki Foundation for Cancer Research (award 615SF).