Non-cancerous cells as well as cancerous cells can produce elevated PSA levels in the test for prostate-specific antigens commonly used to find signs of prostate cancer. Just a quarter of those patients who have a biopsy taken because of heightened PSA levels actually have prostate cancer, according to the National Cancer Institute.
Another procedure, the digital rectal exam, which tries to detect cancerous growths by hand, can be painful and is also not a sure method because small growths are difficult to find.
Schmitthenner's diagnostic procedure — still in its early stages of development — attempts to take a lot of the uncertainty out of prostate cancer detection by using targeting agents that seek out any cancer cells in the prostate and make them stand out with dyes that stick to their membranes.
"By using targeted dyes, we can say, 'These cells light up, so there is a high likelihood of disease in those cells,' " said Schmitthenner, who is an associate research professor in chemistry and imaging science.
A follow-up biopsy could then be taken with a much greater certainty of finding cancer because the dyes would have already pointed to tissues likely to be cancerous. The prostate, which surrounds the urethra, is a gland in the male reproductive system found below the bladder.
Schmitthenner's research — to be effective — would need to be coupled with new technology developed by RIT imaging science professor Navalgund Rao and Dr. Vikram Dogra, who is a professor of radiology, urology and biomedical engineering at the University of Rochester Medical Center.
While Schmittenner provides the chemistry to make the cancerous cells stand out, Rao and Dogra have created the technology to create a clear ultrasound image of prostate cancer.
As it is, there is a degree of collaboration. Rao is on Schmitthenner's team and Schmitthenner has worked with Rao and Dogra.
"This is a fabulous partnership," said Schmitthenner.
RIT student Molly McMahon making a dye. (Photo: photo by James Goodman)
Identifying cancer cells
The Schmitthenner half of the partnership is funded by a $440,367 National Institutes of Health grant. He is supervising a crew of RIT students working on synthesizing the dyes and combining them with targeting agents.
The dye-targeting agent combo will be tested first on cancer cells in petri dishes.
If the research successfully progresses, a person being tested would be injected with the dyes combined with a targeting agent that directs the dyes to a cancerous prostate.
Using the Rao-Dogra laser, near-infrared laser pulses would be beamed at the prostate and absorbed by the dyes that stick to any prostate cancer cells. The laser light would be be adjusted so that only the dyes absorb the laser and create ultrasound.
Ultrasound is typically not an effective way to detect cancer at an early stage because the images are not high resolution. Rather, they are murky.
But in this case the ultrasound would be produced when the laser hits the dyes on the cancer cells.
"It heats the cells. They emit the sound," Schmitthenner said. "We call it making the cancer cells scream."
RIT student Nnamdi Akporji purifies a targeting agent. (Photo: photo by James Goodman)
An acoustic lens device invented by Rao and Dogra would then — like a camera — focus the ultrasound emitted by the dyes as well as amplify it, resulting in a clear ultrasound image of the prostate cancer on a computer screen.
Rao recently received a $436,290 NIH grant, with $49,812 going to Dogra, to continue developing technology — photoacoustic imaging — that, with short bursts of a laser, causes the prostate area to emit ultrasound waves.
Such an approach — without the dyes and targeting agents that Schmitthenner is developing — tries to detect higher hemoglobin concentrations found when the prostate is cancerous. That happens because cancer cells are faster growing than normal cells, resulting in increased blood flow to these cells.
But the higher hemoglobin counts are difficult to detect because the ultrasound created isn't as strong — so Rao and Dogra approached Schmitthenner two years about collaborating.
"He as a chemist has the expertise to attach the dyes to the membranes of the cancer cells," said Rao. "With the hemoglobin, I don't have direct evidence that the ultrasound is coming from the cancer cells."
The dyes, said Schmitthenner, are a much more effective indicator — sticking to the cancer cells and producing ultrasound when hit by the laser..
With these combined technologies, the researchers hope that images of prostate cancer — resembling glowing spots — would show up as distinct areas on the computer screen.
Since one of every seven men, usually older adults, is diagnosed with prostate cancer, improving detection techniques can have widespread implications as the medical profession looks for more exact procedures that would be more cost-effective.
The result would be performing biopsies on a smaller number of people who have a greater likelihood of having cancer, with far fewer adults getting false alarms that they might have cancer.