To address the different partial breast re-irradiation techniques available in the context of second conservative treatment (SCT), as an alternative to salvage mastectomy, for 2nd ipsilateral breast tumor event (IBTE) and summarize their respective oncological and toxicity outcomes.

A literature search was made based on MeSH/PubMed, including papers from 1995 to 2019. Each article was described according to the main irradiation technique, fractionation, oncological results and grade 3 toxicities related to the salvage conservative treatment.

Twenty-two articles were identified, reporting the outcomes of over 1 000 patients. MIB Brachytherapy was the most used re-irradiation technique in case of SCT, with a median 3rdIBTE-FS rate of 88% and summed up grade 3 toxicities of 6%. As for IORT, the average rate of 3rdIBTE-FS was about Finally, external beam partial re-irradiation was recently tested in this indication with encouraging results in terms of tolerance.

When presenting a 2ndIBTE, a SCT can safely be proposed to carefully selected and well-informed patients, as an alternative to salvage mastectomy. MIB appears to be the first intention and most robust choice. IORT, external beam radiotherapy and balloon brachytherapy are interesting alternatives but have only been tested in small series. Further investigations are required and their use should be limited to clinical trial only.