Detection of an internal mammary sentinel lymph node with a peritumoral injection of radiolabelled nanocolloids

Objectives. - Until now, the effectiveness of sentinel lymph-node biopsy (SLNB) has only been demonstrated for the detection of axillary lymphatic involvement in early breast cancer (cT1 N0). The purpose of this study was to evaluate whether the detection of an extra-axillary internal mammary sentinel lymph node (SLN), using peritumoral injection of radiolabelled nanocolloids (NC), can lead to a modification in management for these patients. Materials and methods. - A total of 538 consecutives SLNB was analysed from a cohort of 529 patients. Peri- and infratumoral injections of radiolabelled NC were made under ultrasound control. Results. - A SLN was identified on 524 occasions, 147 (28.1 %) of which were located in the internal mammary chain (IMC). In 10 cases, the SLN in the IMC was not associated with an axillary SLN. One hundred and thirty-five surgical biopsies of the IMC SLN were performed without significant morbidity. Sixteen patients demonstrated local involvement of an IMC SLN, which on seven occasions was isolated to this region. For six of these patients, the finding of SLN involvement led to a recommendation for adjuvant chemotherapy. For 308 patients, for lack of IMC involvement., the adjuvant IMC radiotherapy could have been avoided (i.e.: 95% of the theoretical indications for adjuvant radiotherapy). Conclusions. - Peritumoral injection of radiolabelled NC, associated with a systematic IMC SLN biopsy, enabled the rationalisation of management in patients with stage cT1 breast cancer and did not affect the usual performance of the technique nor led to a significant increase in morbidity. The long-term survival and morbidity outcomes of these therapeutic modifications, particularly with regards to radiotherapy, will need to be demonstrated. (C) 2009 Elsevier Masson SAS. All rights reserved.