A Randomized Prospective Trial of Supine MRI-Guided Versus Wire-Localized Lumpectomy for Breast Cancer

Ann Surg Oncol. 2019 Oct;26(10):3099-3108. doi: 10.1245/s10434-019-07531-4. Epub 2019 Jul 29.


Background: Wire-localized excision of non-palpable breast cancer is imprecise, resulting in positive margins 15-35% of the time.

Methods: Women with a confirmed diagnosis of non-palpable invasive breast cancer (IBC) or ductal carcinoma in situ (DCIS) were randomized to a new technique using preoperative supine magnetic resonance imaging (MRI) with intraoperative optical scanning and tracking (MRI group) or wire-localized (WL group) partial mastectomy. The main outcome measure was the positive margin rate.

Results: In this study, 138 patients were randomly assigned. Sixty-six percent had IBC and DCIS, 22% had IBC, and 12% had DCIS. There were no differences in patient or tumor characteristics between the groups. The proportion of patients with positive margins in the MRI-guided surgery group was half that observed in the WL group (12 vs. 23%; p = 0.08). The specimen volumes in the MRI and WL groups did not differ significantly (74 ± 33.9 mL vs. 69.8 ± 25.1 mL; p = 0.45). The pathologic tumor diameters were underestimated by 2 cm or more in 4% of the cases by MRI and in 9% of the cases by mammography. Positive margins were observed in 68% and 58% of the cases underestimated by 2 cm or more using MRI and mammography, respectively, and in 15% and 14% of the cases not underestimated using MRI and mammography, respectively.

Conclusions: A novel system using supine MRI images co-registered with intraoperative optical scanning and tracking enabled tumors to be resected with a trend toward a lower positive margin rate compared with wire-localized partial mastectomy. Margin positivity was more likely when imaging underestimated pathologic tumor size.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Breast Neoplasms / pathology
  • Breast Neoplasms / surgery*
  • Carcinoma, Ductal, Breast / pathology
  • Carcinoma, Ductal, Breast / surgery*
  • Carcinoma, Intraductal, Noninfiltrating / pathology
  • Carcinoma, Intraductal, Noninfiltrating / surgery*
  • Carcinoma, Lobular / pathology
  • Carcinoma, Lobular / surgery*
  • Female
  • Follow-Up Studies
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Mammography / methods*
  • Margins of Excision
  • Mastectomy, Segmental / methods*
  • Middle Aged
  • Prognosis
  • Prospective Studies