[Conservative treatment for breast cancer: optimization of the tumor bed localization]

The main objective was to assess contributions and limits of surgical clips combined with computed tomography to define the tumor bed after conservative treatment of breast cancer. This retrospective observational study enrolled 16 patients treated by lumpectomy with surgical clips placed in the tumor bed.

We assessed the difficulties in localizing the tumour bed based on collected data (i.e. clinical description, mammography, ultrasound examination, surgical procedure and pathology data). The clip's number and localization, and the volumes of the boost were also analyzed.

There was no preoperative occurrence of localization in 57 % of cases for palpable tumours, and in 13 % of cases where the lesion was subclinical. The collected data did not allow establishing a precise localization. The mean number of surgical clips per patient was 4 (range 1-9), and the delineation of the target volumes by radiation oncologists was not standardized. Oncoplastic techniques may produce difficulties in the localization of tumour bed.

The placement of surgical clips by the surgeon is helpful, primarily when oncoplastic techniques are used. In many situations, these clips may cause problems of interpretation. In order to optimize the delineation of the boost, we propose a multidisciplinary approach and methodology to be used at the Henri Becquerel Cancer Centre.