"We used an ultrasound intensity higher than that used for imaging, but much lower than the high intensities used to ablate tissue. And we saw that this new use had a profound effect on shutting down the blood flow to the tumor and reducing the growth of the tumor in mice," said Chandra Sehgal, PhD, Director of Ultrasound Research in the Department of Radiology at Penn and the study's principal investigator.
"We wanted to study this use of ultrasound because we observed that some of these newly formed vessels created by tumors are very weak in nature, and if you turn on low-intensity ultrasound vibrations you can disrupt the blood flow through these vessels," explained Andrew Wood, DVSc, PhD, a co-investigator of the study and based in the University of Pennsylvania School of Veterinary Medicine.
Sehgal adds, "This approach is in keeping with the latest study of cancer treatment utilizing antiangiogenic and antivascular therapies, in which we look for ways to stop the growth of the vessels supplying blood and nutrition to the tumors, rather than develop methods to kill the tumor cells themselves."
For years, ultrasound has been used for clinical imaging and for therapeutic action in physical therapy. But now, Sehgal explains, "These results are extremely encouraging. They raise the possibility that, in the future, treatments with ultrasound either alone or with chemotherapeutic and antivascular agents could be used to treat cancers."
The results of this study were published in the October 2005 issue of "Ultrasound in Medicine and Biology." You can access it on-line at: www.sciencedirect.com (search for the UMB journal and then access Volume 31 - October 2005, article 15 "The Antivascular Action of Physiotherapy Ultrasound on Murine Tumors").
Editor's Notes: To schedule an interview with Dr. Chandra Sehgal, the principal investigator of the study or Dr. Andrew Wood, the first author of the study, please contact Susanne Hartman at 215-349-5964 or firstname.lastname@example.org.
This study was funded in part by the National Institutes of Health (NIH). Related images available upon request.
PENN Medicine is a $2.7 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.
Penn's School of Medicine is ranked #2 in the nation for receipt of NIH research funds; and ranked #4 in the nation in U.S. News & World Report's most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.
The University of Pennsylvania Health System includes three hospitals [Hospital of the University of Pennsylvania, which is consistently ranked one of the nation's few "Honor Roll" hospitals by U.S. News & World Report; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center]; a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home care and hospice.