A microbubble technique, developed by British researchers, is a new technique that uses tiny bubbles to detect cancer.
Experts at Maidstone and Tunbridge Wells NHS Trust, Kent, pioneered the microbubble technique, the results of which suggested that breast cancer patients could avoid repeat surgery.
Lead researcher Dr Ali Sever, a consultant radiologist, said the tests gave a whole new dimension to the way they treat patients.
"This is a world first. The test only takes a few minutes to perform and has transformed the way we care for patients," the BBC quoted him as saying.
Dr Sever added: "The use of ultrasound with microbubbles to detect the sentinel lymph node is unique and something that will benefit breast cancer care around the world."
Sue Jones, a consultant breast and oncoplastic surgeon who helped developed the procedure, said: "Telling women who have undergone breast cancer surgery that they need another operation because the cancer has spread to the sentinel lymph node is the worst news they can hear.
"It is a real emotional set back in their cancer journey.
"While still traumatic, patients seem to deal with this news much better if they find out before operation that the lymph glands have cancer in them."
Consultant breast surgeon Mr Peter Jones also said: "It is possible for breast teams to use this test and thousands of women can avoid unnecessary surgery."
The results were published in the British Journal of Surgery.