[Breast cancer: role of MRI in follow-up of cases treated]. / Cancer du sein : rôle de l'IRM dans le suivi des cas traités.

Conventional imaging (CI) for breast cancer includes mammography and ultrasound. Its limited efficiency is especially manifest for breast cancer follow-up after breast-conserving therapy (i.e. exclusive radiation therapy) and after breast implant. Lack of evidence for definitive diagnosis increases the number of invasive explorations. To improve the specificity of the diagnosis between recurrence or fibrosis, we describe the interest of new imaging (NI) techniques: post-contrast MRI, and MR angiography (MRA), realized in 1 exam. Between October 1993 and December 1994, 82 patients were eligible for these investigations. All patients had an history of conservative breast cancer treatment of breast implant following mastectomy. In all cases CI was not contributive for a precise diagnosis; therefore a biopsy was performed and confirmed the diagnosis of breast cancer. NI was done before biopsy and compared results are following. 19 more patients were evaluated for primary chemotherapeutic response, including a total of 101 patients. Regarding the follow-up of prosthesis and conservative treatment, the correlation with histological control was obtained in 95% with four false diagnoses due to confusion between retroprosthesis relapse and inflammation. Historadiologic correlation were close to 90% for the evaluation of primary chemotherapeutic response. Studies are ongoing to confirm those preliminary findings. Though expansive, these techniques might be cost-effective if they result in a substantial decrease of unnecessary surgical invasive procedures.