Physician researchers at the Seattle Cancer Care Alliance and University of Washington Medical Center conducted the study on 167 patients, who went for radiation therapy for invasive breast cancer after surgical staging of their tumors,
The researchers found that the tumors' physiological information shown on MRI scans was linked to surgically based findings of cancer having spread to lymph nodes, indicating that breast MRI could tell whether women who would be going for surgery would need radiation therapy later and how much.
The results of the study are important, as the standard of care for women with breast cancer has improved in the past five years. Earlier decisions related with radiation therapy were taken after surgery and before chemotherapy,
"When you give chemotherapy first, and then perform the surgery to remove the cancer and sample the lymph nodes, you reduce your ability to know whether there was cancer in the axillary (underarm) lymph nodes before the patient was treated with chemotherapy," said Dr. Christopher Loiselle, a resident in the Department of Radiation Oncology at UW Medical Center.
He said: "This raises the question: is there another way to stage those lymph nodes? Our study showed that tumor characteristics as seen on an MRI scan may be the answer."
He claimed that the biggest advantage of this study was that some women could be spared radiation therapy, especially those with smaller tumors and tumors that have not spread to the lymph nodes,
MRI scans typically make use of a contrast dye that highlights the size and location of the tumor as well as details the blood vessels feeding the tumor. Loiselle said that the kinetics or activity of the contrast dye in the tumor gave some key parameters for comparing MRI to traditional surgical tumor staging
"MRI is evolving rapidly as a diagnostic tool for breast cancer, particularly among women with high risk for the disease, because not only does it give us traditional anatomic information about tumors but information about the biology of the tumor as well," said Loiselle.
The study was presented during the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Boston.