Breast MRI Best at Tracking Response to Chemo: Study

WEDNESDAY, May 23 (HealthDay News) — Getting chemotherapy before breast cancer surgery can mean the difference between a mastectomy or a breast-conserving lumpectomy, experts say.

And new research shows that getting an MRI during the first round of chemo can help predict quickly if the cancer will respond to the treatment.

MRI works better than clinical examination of the tumor, the standard way to assess how well the chemotherapy is working, said researcher Dr. Nola Hylton, a professor of radiology and biomedical imaging at the University of California, San Francisco.

Although many doctors order an MRI after all rounds of chemotherapy are finished, Hylton’s team did MRIs before, during and after a chemo cycle, and also when all of the chemotherapy was finished.

“What we are trying to do is fine-tune MRI so it can be a more sensitive measure of whether people are responding [to the chemo],” Hylton said.

At all points, MRI measurements of tumors were more accurate than a clinical exam, in which the doctor palpates the tumor and evaluates whether it is responding to the chemo.

“This initial finding said that after only one cycle of treatment, measuring the change in the tumor volume [by MRI] was very predictive of whether that patient ultimately had a good response to all the chemotherapy,” Hylton said.

Previous research has found that women who get chemotherapy before their surgery are more likely to be able to have breast-conserving surgery than women given chemo after their surgery.

The new study included 216 women, aged 26 to 68, who had invasive breast cancer (stage 2 or 3).

The study is scheduled to be published in the June issue of the journal Radiology.

The findings don’t surprise Dr. Joanne Mortimer, director of the Women’s Cancer Program and co-director of the Breast Cancer Program at the City of Hope Comprehensive Cancer Center in Duarte, Calif.

“It’s a great idea,” Mortimer said of performing the MRI sooner. “The MRI seems to be a more objective way [to gauge effectiveness of chemo].”

Already, Mortimer said, many doctors are ordering an MRI after chemotherapy is complete. “The practice is to perform the MRI after the entire chemo session,” she said.

The cost of an MRI ranges greatly, but without insurance coverage it is often $1,000 or higher.

“When you give chemotherapy, the blood supply to the tumor changes,” Mortimer said.

The MRI detects activity such as blood vessel formation in tumors, a marker of whether the tumor is responding to chemo, Hylton noted.

More information

To learn more about MRIs, visit the American College of Radiology.