The Impact of Preoperative Breast MRI in Patients With Breast Cancer Selected for Breast Conserving Surgery
The Impact of Preoperative Breast MRI in Patients With Breast Cancer Selected for Breast Conserving Surgery
The purpose of this prospective observational study is to evaluate the impact of preoperative
 breast MRI in patients with breast cancer selected for breast- conserving surgery. MRI is a
 more sensitive radiological modality than mammography and ultrasonography. Patients with
 small breast cancers are, based on conventional modalities, selected for breast-conserving
 surgery. If preoperative breast MRI reveal additional lesions in the breasts, and malignancy
 is confirmed histopathologically, this finding leads to a change of surgical method to
 mastectomy.
The aim of the study is to evaluate the impact of preoperative breast MRI on primary surgical
 treatment in a highly specialized multidisciplinary breast cancer clinic. The clinic serves a
 population of 237.000. The diagnostic tools routinely used are conventional mammography,
 ultrasound with core needle biopsy, and clinical examination including palpation of breast
 and axillary nodes. If indicated, the examination includes ultrasound examination and fine
 needle biopsy of axillary glands. We offer all patients selected for breast-conserving
 surgery preoperative breast MRI.

 We include consecutively breast cancer lesions in women aged 35-75 in a prospective study,
 collecting data from January 2009 to December 2010. The patients are all selected for
 breast-conserving surgery based on the criteria recommended by the Norwegian Breast Cancer
 Group. That is, tumor ≤ 4 cm, or acceptable tumor:breast ratio, and age > 35. Multifocal
 lesions, defined as more than one tumor > 1 cm apart, size of tumor > 4 cm, or a large
 tumor:breast ratio, extensive ductal carcinoma in situ (DCIS), or known genetic disposition
 for breast cancer, indicates mastectomy according to these criterias. In addition, when
 postoperative radiation therapy is contraindicated, mastectomy is indicated. If the patients
 fill the criteria for breast-conserving surgery, they are offered preoperative breast MRI and
 included in the study. Patients who either choose mastectomy, or does not get a breast MRI
 for technical reasons, are excluded from the study. Two experienced breast radiologists
 evaluate the breast MRIs, and three experienced breast radiologists study the mammographies
 and perform the ultrasound examinations and biopsies. All additional MRI findings are
 examined by ultrasound-guided biopsy and given a histological diagnose before it influence
 the surgical method.

 A formal application has been presented to the regional ethical commitee. Since this is an
 observational study of established practice, the commitee replied that approval was not
 required.
Inclusion Criteria:

 -  Patients ≥ 35 years and ≤ 75 years

 -  Indication for breast-conserving surgery according to criteria recommended by the
 Norwegian Breast Cancer Group:

 -  Tumor < 4 cm and acceptable tumor:breast ratio

 -  Tumor not infiltrating skin or pectoral fascia

 -  No multifocality (that is 2 foci or more, > 1 cm apart)

 Exclusion Criteria:

 -  Patient choose mastectomy

 -  Technical problems with the MR machine

 -  Pacemaker

 -  Anxiety/claustrophobia