Pre-operative MRI for breast cancer patients may need to be done in a different position

By Sally Robertson, B.Sc.Jun 23 2016

The difference in how a woman is positioned during MRI prior to breast conserving surgery and how she is positioned during the surgery distorts and displaces tumors while the surgery is being performed, report researchers.

Pre-operative breast MRI is traditionally carried out while a woman is lying prone or face-down, while the actual surgery is performed while she is lying supine or face-up.

However, the current study has shown that there is a greater likelihood of breast tumors being completely removed during an operation if women receive additional MRI whilst positioned on their backs, as they are during surgery.

Although MRI has proved an effective and sensitive tool for the detection of breast tumors, no evidence has yet shown that pre-surgery MRI results in improved outcomes for women who have undergone breast conserving surgery.

Radiologist Eva Gombos (Brigham and Women’s Hospital) and colleagues compared prone and supine pre-surgery MRI exams carried out for 12 women with breast cancer who underwent breast conserving lumpectomies. The team recorded the differences in the size, shape and position of the tumors between the two imaging positions and found that the size and location of tumors differed significantly, depending on which position the women were in during MRI. There was considerable deformity of the breast and the position of the tumor when imaging was performed in the prone position.

Supine MRI, when performed in addition to standard prone breast MRI, may help detect a remnant tumor and ensure clear margins to prevent re-operation,”

Co-author Mehra Golshan, Chair in surgical oncology at BWH.

Currently, up to 40% of women who have this surgery need to have a second surgery to remove remnant tumor. The authors believe that surgeons receiving MRI images of their patients while they are lying on their backs may help them to achieve removal of the entire tumor more successfully, since this is the position women are in during surgery.

"Accounting for change in size and shape caused by displacement and deformation of the tumor between standard imaging in the prone position and operative supine position, our analysis highlights that supine MRI before surgery may provide surgeons with more detailed and accurate information and could lead to effective tumor removal," says Gombos.

Sources

• http://www.eurekalert.org/pub_releases/2016-06/bawh-hbm061716.php
• https://www.researchgate.net/blog/post/are-we-performing-breast-mri-the-wrong-way-around