Promise of better tracking, with more clarity

Justine Cadet, Editorial Director

  While imaging has become firmly entrenched in the patient care cycle, preclinical imaging is revealing the promise of enhanced methods of tracking varied conditions with even more clarity through the use of new tracers.

One study revealed that 89Zr-DFO-7E11 displays high tumor-to-background tissue contrast in immuno-PET and can be used as a tool to monitor and quantify with high specificity tumor response in prostate-specific membrane antigen (PSMA)-positive prostate cancer. Using mice models, the researchers evaluated the potential of assessing tumor response in vivo after radiotherapy.

The researchers reported “excellent image contrast” with immuno-PET, and the 7E11 uptake was statistically increased in irradiated versus control tumor as measured by immuno-PET and bio-distribution studies.

Thus, they concluded that that “89Zr-7E11 for immuno-PET of changing PSMA levels has the potential to be used in monitoring patient response to therapies including various chemotherapies and radiation therapy,” which could have grand implications for cancer patients in the future.

Also, for the difficult aspects of skeletal imaging, a new tracer may represent new possibilities.

Although not commonly used in current clinical practice, the PET agent 18F-NaF provides an “excellent alternative” to the standard tracers used for radionuclide bone scintigraphy, the study authors wrote. Laura A. Drubach, MD, of the department of radiology at the Children's Hospital in Boston, and colleagues explained that 18F-labeled NaF has a biodistribution generally similar to that of 99mTc-MDP, but its lower protein binding in blood allows a more rapid single-passage extraction by bone, thus permitting earlier image acquisition.

They found that skeletal imaging with 18F-NaF harnesses both the imaging characteristics of PET and the improved biodistribution of the fluoride tracer in comparison with standard nuclear techniques, resulting in images that can effectively be used to investigate the cause of bone pain in children.

The future implications include “a rational basis for the use of 18F-NaF PET when imaging trauma patients and those with sports injuries.” And, in the setting of trauma related to child abuse, “18F-NaF PET has been shown to be useful in the detection of skeletal fractures and, in particular, to be highly sensitive for the detection of rib fractures that may be difficult to identify radiographically,” they added.

Of course, more studies need to follow to validate the findings of such progress, but the drum continues to beat from the preclinical space to the patient setting.

Please let us know what preclinical imaging research your facility is undertaking.

Justine Cadet
jcadet@trimedmedia.com