CHICAGO, June 5 (UPI) -- Targeting one dose of radiation on the area where a breast tumor was removed is as effective as radiating the entire breast for weeks, U.S. scientists said.
The dose can be delivered during surgery, limiting radiation treatment of the cancer to a single day in many cases, said the study released Saturday at the American Society of Clinical Oncology's annual meeting in Chicago.
Typically, radiation therapy is given five days a week for as long as 6 1/2 weeks, the Chicago Tribune reported Saturday.
The study's results challenge "the existing paradigm of the treatment of breast cancer," said the researchers, who analyzed results from more than 2,000 breast cancer patients in nine countries in Europe, North America and Asia.
The single-dose therapy also avoids irradiation of the heart, lung and esophagus, said Dr. Dennis Holmes of the University of Southern California's Norris Comprehensive Cancer Center.
"It's best for women with a small tumor that is well-defined and involves only one portion of the breast," Holmes said.