New Imaging Technique Could Spot Early Cancers (HealthDay)

MONDAY, Aug. 18 (HealthDay News) -- Nanotechnology may offer doctors anoninvasive way to detect early stages of cancer and also help monitortreatment, a new report says.

Researchers at Stanford University School of Medicine recentlydemonstrated the new approach using "smart" targeted carbon nanotubes tozero in on cancer cells in living mice, followed by laser scans of theanimals in which the nanotubes absorbed the laser energy and releasedultrasound waves to highlight the locations of the tumor cells.

"This imaging modality allows us to see things we've never been able tosee before," study author Adam de la Zerda, a doctoral student in Stanfordelectrical engineering, said in a news release issued by theuniversity.

The findings were expected to be published online Aug. 17 in NatureNanotechnology.

The technology takes advantage of the "photoacoustic effect," aphysical phenomenon in which light hits an object and is converted intosound. Shining light on an object heats it up, de la Zerda said.

"Think of a black car parked in the sun," he said. The car warms up,and the metal expands. Later, the cooling, shrinking metal makes little"tink" sounds.

"We shine light on a nanotube and listen to the ultrasound waves comingout of it," de la Zerda said.

The technique is faster and costs less than an MRI scan and requires noionizing radiation like a PET-CT scan, the researchers said. Its abilityto look 2 inches deep into the body would make it helpful for looking attissues in the breast or prostate gland.

The method is sensitive enough to detect minute, early tumors thatnormally can't be seen, the researchers said. Also, the scanners couldalso be adapted to endoscopes, enabling views of internal organs.

Coatings on the nanotubes could also be altered so doctors couldreceive diagnostic information about a tumor, de la Zerda said. Forinstance, molecules put on nanotubes could tell a doctor which anti-cancerdrugs would work on a breast tumor.

"We will be able to ask a tumor: Are you responding to chemotherapy ornot?" de la Zerda said. "This should give us early information long beforethe tumor shrinks or grows."

A companion study in mice, published in Nature Nanotechnology inApril, found the carbon nanotubes appear to be safe to inject, althoughfurther testing is needed before testing can begin in humans.

More information

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