[Salvage prostate brachytherapy: A solution for local failures after a primary radiation therapy?]

Salvage brachytherapy after a first prostate radiation therapy is an emerging technique, which has to be considered in the therapeutic armamentarium in the clinically challenging context of patients with isolated local failure from prostate cancer who may still be considered for cure. These occult failures are more and more frequently diagnosed at an early stage, thanks to targeted biopsies and advances in imaging modalities, such as multiparametric MRI and PET-CT. Salvage brachytherapy benefits from the implantation accuracy of brachytherapy procedures using 3D dosimetry and has resulted in more than 50% tumour control rates with long-term. Incontinence rates are always below those of other salvage treatments such as radical prostatectomy, HIFU or cryotherapy. Today, a consensus has been reached to better define good candidates for salvage brachytherapy with respect to disease characteristics at baseline and at failure. No consensus has been clearly defined yet regarding the choice of the technique (low or high dose rate), the total dose to be delivered, or the volume to be implanted (whole gland or focal). While we await robust data from recently completed phase II studies and given the heterogeneous results in the literature, this technique (although already included in the last 2016 NCCN guidelines) remains to be precisely evaluated, optimally within the frame of controlled trials.