Scanning goes sci-fi in investigating tumor genetic activity
Researchers are using CT scans to discern the genetic activity of a tumor, which could provide essential information to help diagnose and treat patients in a highly individualized fashion, according to a study published in the online version of Nature Biotechnology. The research was done at the Stanford University School of Medicine and the University of California, San Diego School of Medicine.

"Potentially in the future one can use imaging to directly reveal multiple features of diseases that will make it much easier to carry out personalized medicine, where you are making diagnoses and treatment decisions based exactly on what is happening in a person," said co-senior author Howard Chang, MD, PhD, assistant professor of dermatology at Stanford, who led the genomics arm of the study.

The work aims to help doctors obtain the molecular details of a specific tumor or disease without having to remove body tissue for a biopsy. "Ideally, we would have personalized medicine achieved in a noninvasive manner," said the study’s other senior author, Michael Kuo, MD, assistant professor of interventional radiology at UCSD.

Chang feels the research effort recalls sci-fi television.  "In almost every episode of 'Star Trek,' there is a device called a tricorder, which they used noninvasively to scan living or nonliving matter to determine its molecular makeup," said Chang. "Something like that would be very, very useful."

Used in clinical practice this approach would avoid the pain and risk of infection and bleeding from a biopsy and would not destroy tissue. Thus, the same site could be tested again and again.

At the time the project started at Stanford in 2001, the medical school was ground-zero for studies of DNA microarrays, the lab tools that can screen thousands of genes at a time, developed by biochemistry professor Patrick Brown, MD, PhD. Microarrays have proven to be extremely useful for identifying groups of genes that are more active or less active in a disease such as cancer, compared with normal tissue.

"When we look at noninvasive images, there are lots and lots of different patterns that had no known meaning," said Chang. "We thought that maybe we could come up with a way to systematically connect the gene activity seen with microarrays to imaging patterns, to translate meaning into three different types of languages, from genes to images and then to outcome of the disease process."

The researchers said that they are still far from clinical application of the tools, but stressed the importance of making a strong link between imaging and molecular gene activity.

Radiologists – who are already experts in noticing the visual differences between normal and pathological tissues – will benefit greatly from additional expertise in knowing what to look for and what it means.