FRIDAY, Sept. 22, 2006 (HealthDay News) -- Standard MRI is more accurate than another method, multidetector computed tomography (MDCT), in determining if and how far breast cancer has spread into breast ducts, Japanese researchers report.
They recommend that MRI should be used to assess patients before they have breast-conserving surgery (lumpectomy).
Researchers used MRI and MDCT on 69 patients with invasive breast cancer. In 44 of the cases, malignancy had an intraductal component.
MRI correctly identified 33 of the 44 cases, while MDCT correctly identified 27.
"MRI revealed the presence of the intraductal component with significantly higher sensitivity (75 percent) compared to MDCT (61 percent)," Dr. Akiko Shimauchi, of Tohoku University, said in a prepared statement.
"The lesions that were missed by both examinations were the ductal extension type, i.e. the tumor included a dominant mass with an outward extension of cancer cells, with a relatively small ductal component," she said.
MRI was better able to detect the smaller ductal components than MDCT, the study found.
"Patients have a lower survival rate if their surgical margins are positive for tumor cells. A positive surgical margin is usually the result of inadequate resection of the cancer's intraductal component," Shimauchi said. "Accurate preoperative diagnosis of the intraductal component allows the surgeon to achieve a cancer-free surgical margin."
The study was published in the August issue of the American Journal of Roentgenology.
The U.S. National Cancer Institute has more about breast cancer surgery.