Because existing ultrasound machines can be used, the cost is relatively low at about $125 per exam, with just the extra cost of the microbubbles.
Explore This IssueApril 2011
Kenneth Hoyt, PhD, assistant professor of radiology at the University of Alabama at Birmingham, said his group has been working to refine the process of coating microbubbles with antibodies that bind only to biomarkers in tumor vasculature.
“This technique can enhance signal specificity at tumor sites and promises such things as cancer detection at earlier stages where successful treatment is much more likely,” Dr. Hoyt said.
Microbubbles have also been found to help with drug delivery; the mechanical stresses of the procedure can temporarily increase the permeability of the cell membrane.
“It is essentially a lipid- or protein-shelled microbubble with a hollow gas core,” Dr. Hoyt said. “You could imagine loading that microbubble with some drug. Since these microbubbles are sensitive to ultrasound exposure, you can actually burst them at the tumor site to maximize drug delivery. Once again, this is a promising technology that we are on the verge of hearing much more about.”
The familiarity of ultrasound imaging might bode well for its future use with these refinements in place.
Randal Weber, MD, professor and director of surgical services in the department of head and neck surgery at the University of Texas’ M.D. Anderson Cancer Center in Houston, said surgeons are always looking for improved imaging that will delineate the extent of disease and facilitate surgical planning.
“For those of us that do tumor surgery, readily available 3-D imaging that’s not too resource- or labor-intensive could be useful for tumors of the skull base and parapharyngeal space,” he said. “It helps you plan an operation. Although radiologists can readily reconstruct 2-D images into 3-D images in their mind, it’s harder for those of us who don’t do that very often or don’t think that way.”
In this technique, light is restricted to just blue and green wavelengths, helping to highlight areas of increased vascularity that can indicate possible tumor tissue.
“One of our frustrations is that we often miss small tumors, or, in patients that have had radiation, it can be very difficult to evaluate because the tissue has been damaged by the radiation,” Dr. Farwell said. “And any tools that we have to make tumors more obvious will increase our sensitivity in picking up these tumors at an earlier stage.”