New Oxygen-enhanced Imaging Technique Identifies Aggressive Prostate Cancer in Mice

New Oxygen-enhanced Imaging Technique Identifies Aggressive Prostate Cancer in Mice

A new imaging technique called oxygen enhanced optoacoustic tomography (OE-OT) may improve the ability to distinguish between aggressive and less-aggressive prostate cancer cases, identifying those patients who can undergo chemo and/or radiation therapy, according to researchers.

The study, titled “Oxygen Enhanced Optoacoustic Tomography (OE-OT) Reveals Vascular Dynamics in Murine Models of Prostate Cancer,” was published in the journal Theranostics.

Tumor cells grow much faster than normal cells and eventually need their own supply of blood. But the resulting blood vessels tend to have different properties between patients. A tumor may have good or poor quality blood vessels, both of which lead to very different tumor environments. Poor quality blood vessels contribute to a condition called hypoxia, which refers to low oxygen levels, and can lead to increased resistance to chemotherapy and radiotherapy.

Therefore, the ability to noninvasively image the oxygen supply of tumors in prostate cancer can help improve diagnosis and aid with the staging of the disease by being able to identify the more aggressive, hypoxic tumors and the less aggressive, oxygen-reliant tumors.

Currently, there are some approaches that can measure oxygen supply that have been investigated in cancer, such as special versions of magnetic resonance imaging (MRI) and positron emission tomography (PET). But while these methods hold promise, they have limitations. Therefore, there is a need for better imaging of oxygen supply.

The new approach, called optoacoustic tomography (OT), currently in clinical trials, has the ability to help visualize oxygen supply in preclinical cancer models. This technique was developed using a combination of light and sound, which allowed scientists to record oxygen levels on an imaging device.

Scientists in the U.K. developed a version of the technique, OE-OT, to measure oxygen levels in two mouse models of prostate cancer. It involved administering a short burst of pure oxygen to mice that had two different types of prostate cancer and then monitoring the speed and efficiency of the extra oxygen in reaching the tumor through the blood vessels.

Researchers were able to see that the oxygen reached the tumors that had better quality blood vessels faster compared to the mice that had poor quality blood vessels. When performing this technique on static OT, there were no differences found between the two mouse models, indicating that oxygen is necessary to view the blood vessel differences.

OE-OT results discovered in this study were highly repeatable and correlated to other experiments that also investigated tumor vessel function in these mice.

Therefore, OE-OT holds significant potential for clinical application in prostate cancer patients not only for diagnosis but also determining which patients should undergo chemo and radiotherapy and those who wouldn’t benefit from these aggressive treatments.

“Our new imaging technique gives us a clearer picture of the heart of prostate cancer than we have ever had before,” Dr. Sarah Bohndiek, lead author and scientist at Cancer Research UK Cambridge Institute, said in a press release.

“The tortuous nature of blood vessels can leave tumors starved of oxygen — making the cancer resistant to radiotherapy and chemotherapy and very difficult to treat,” she said. “If we can translate this technology to the clinic, we could provide a noninvasive way to stratify men for treatment and monitor the effect of different therapies.”

One comment

  1. Stephen B. Strum, MD, FACP says:

    For us clinicians treating prostate cancer there are many publications that are stimulating/tantalizing but their ability to be translated into patient care now or in the next few months is often just not there. I term this stimulation without gratification and perhaps we can come up with a new concept called Translational Coefficient (TC) that is an indicator of how likely something new will make it into the sphere of patient evaluation and/or treatment in the next 6 months (TC4), 1 year (TC3), 2 years (TC2), 3 or more years (TC1), or unlikely in the foreseeable future (TC0). A TC of 2-4 is worth keeping tabs on but lower levels are likely to disappear into the vapor of “could’ve beens”, and there are many of those.

    As a student of prostate cancer since 1983, and having treated many thousands of patients over the last almost 35 years, there are currently many technologies that are NOT making it into real time medicine. Even basic imaging studies to ascertain stage of prostate cancer are not being subjected to head-to-head studies to determine is one imaging study better than the other (e.g., 68Ga-PSMA PET/CT versus Tc99 bone imaging vs CT abdomen/pelvis vs NaF PET/CT). How in the world does a clinician chose when no direct comparison studies are reported?!

    Insofar as oxygen enhanced optoacoustic tomography (OE-OT), this sounds wonderful but how many years will go by before this is clinically available and after that will there be a study(ies) to show superiority over other testing? Is multi-parametric MRI (mp-MRI) that uses DCE (dynamic contrast enhancement) able to be a more accurate test if DCE is discarded and OE-OT used instead? Is there a mouse study of prostate cancer that shows this superiority of OE-OT right now? We need usable new developments and less so for those that take the life time of the clinician from concept to patient use.

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