Original Article
Impact of preoperative magnetic resonance imaging in breast cancer patients candidates for an intraoperative partial breast irradiation
Abstract
Objective: Partial breast irradiation (PBI) could be a reasonable option in patients with early breast cancer (BC) provided that an adequate patient selection, based on robustly established criteria is performed. A preoperative magnetic resonance imaging (MRI) in patient selection for PBI is not consensual. The aim of this retrospective study was to assess the impact of preoperative MRI on patient eligibility for PBI.
Methods: Since March 2012, patients with early BC, meeting the Inca’s criteria for PBI were offered the possibility of shortened treatment through intra-operative radiation therapy, either in a prospective trial or off protocol. Eligibility criteria based on physical examination, mammography and ultrasound, and a pathological exam of biopsy, were as follows: menopaused woman 55 years or older with a T1, N0, hormonal-receptor-positive and HER2-negative, invasive, non-lobular epithelioma, without extensive intraductal component (defined as more than 25% of ductal component on biopsy), non-fast-growing tumor, without lymphovascular invasion (LVI), without criteria for adjuvant chemotherapy. A contrast-enhanced MRI was not routinely performed, but at the discretion of the physician as was the rule in TARGIT-A trial. We assessed the rate of additional cancer revealed by the preoperative MRI, remote in the same breast not detected by mammography and/or ultrasound.
Results: Between March 2012 and February 2014, 179 early BC patients meeting the required criteria were planned for an intraoperative radiotherapy (IORT)-PBI. Seventy nine percent of them (141/179) underwent a breast MRI as part of preoperative assessment. ACR3-ACR4 abnormalities not detected by mammograms or ultrasound were found in 44 patients (31%), which prompted a focused mammary ultra-sound, and a biopsy was realized in 29/141 patients (21%). A second breast carcinoma was found in 10 patients (7% of patients with a preoperative MRI, 4 ipsilateral lesions, 5 contralateral lesions, and one both ipsi- and contralateral lesion, precluding IORT-PBI in 5/141 patients (4%).
Conclusions: The use of preoperative MRI in patient staging leads to diagnosis of an ipsilateral second BC in 4% of cases, which appears substantial in a highly selected population. We therefore support the routine use of this exam for the staging of patient candidate for a PBI.
Methods: Since March 2012, patients with early BC, meeting the Inca’s criteria for PBI were offered the possibility of shortened treatment through intra-operative radiation therapy, either in a prospective trial or off protocol. Eligibility criteria based on physical examination, mammography and ultrasound, and a pathological exam of biopsy, were as follows: menopaused woman 55 years or older with a T1, N0, hormonal-receptor-positive and HER2-negative, invasive, non-lobular epithelioma, without extensive intraductal component (defined as more than 25% of ductal component on biopsy), non-fast-growing tumor, without lymphovascular invasion (LVI), without criteria for adjuvant chemotherapy. A contrast-enhanced MRI was not routinely performed, but at the discretion of the physician as was the rule in TARGIT-A trial. We assessed the rate of additional cancer revealed by the preoperative MRI, remote in the same breast not detected by mammography and/or ultrasound.
Results: Between March 2012 and February 2014, 179 early BC patients meeting the required criteria were planned for an intraoperative radiotherapy (IORT)-PBI. Seventy nine percent of them (141/179) underwent a breast MRI as part of preoperative assessment. ACR3-ACR4 abnormalities not detected by mammograms or ultrasound were found in 44 patients (31%), which prompted a focused mammary ultra-sound, and a biopsy was realized in 29/141 patients (21%). A second breast carcinoma was found in 10 patients (7% of patients with a preoperative MRI, 4 ipsilateral lesions, 5 contralateral lesions, and one both ipsi- and contralateral lesion, precluding IORT-PBI in 5/141 patients (4%).
Conclusions: The use of preoperative MRI in patient staging leads to diagnosis of an ipsilateral second BC in 4% of cases, which appears substantial in a highly selected population. We therefore support the routine use of this exam for the staging of patient candidate for a PBI.
