UCSF researchers test out new scanning technology

January 6, 2011 8:02:52 PM PST
Researchers at UCSF are getting a new look at a cancer that affects one in six men. Prostate cancer is the second leading cause of cancer death among American men, but now vivid new images could help determine the best course of treatment.

Like many men diagnosed with lower-grade prostate cancer, Jon Nowlin has opted for a treatment strategy called active-surveillance -- postponing potentially risky treatments while doctors monitor his cancer. And now, an experimental technology is making that surveillance much more precise.

"You have some idea of what's going on in terms of where is the cancer, how big is it, is it getting larger with time?" says Nowlin.

"These metabolic signatures are what gives us confidence that these regions are really cancer," says UCSF Radiology professor John Kurhanewicz, Ph.D.

Kurhanewicz is part of a research team at UCSF that's experimenting with a new imaging agent. It allows researchers to view the growth of cancer cells in real time, by spying on their metabolism.

"It's been known for a long time that cancer cells have a different metabolism than other cells so. And so we're taking advantage of what's been known for decades, but that didn't have the technology to look at," says Kurhanewicz.

To accomplish that, technicians cool a compound called pyruvate to very low temperatures. That has the effect of stirring up its atoms to make it instantly visible through an MRI. The mixture is then injected back into the patient before the scan. Researchers say the key, is that pyruvate is a naturally occurring compound, used by cells to create energy.

"And we know that cancer cells, which are rapidly dividing and have really high metabolism rates, will take up those substances before healthy cells take up those nutrients," says professor Marcus Ferrone, PharmD, from UCSF.

Ferrone says the MRI is able to focus in on the pyruvate as the cancer cells are metabolizing it. Without the new technique, the scan on the left looks normal, but the one on the right, pinpoints the concentration of pyruvate in the cancerous area.

"We're able to do this fairly quickly in a short period of time, and get a lot of data in real time and watch it change over a period of minutes," says Ferrone.

He says that ability also allows them to determine if the cancer is growing and how aggressively. For patients and their doctors, it offers a more accurate assessment on which to base their decisions.

"The saying about a picture being worth a thousand words, is really true in this setting too," says Andrea Harztark, M.D. from UCSF.

"Anything we can do to improve the accuracy in locating the tumors, determining how big they are, how aggressive they might be, is great," says Nowlin.

So far the trials have shown no side effects. In the next round, researchers plan to increase the levels of pyruvate, in the hope of producing even more precise images.

This story was written and proced by Tim Didion

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