e558 Background: Salvage options for those with local recurrence after XRT include surgery, brachytherapy, cryotherapy or high-frequency ultrasound. However, the risk of significant complications (e.g. fistula, incontinence, bladder neck contracture), is not insignificant. The sensitivity of multiparametric MRI in detecting viable cancer within the prostate is now more than 70%. The objectives of this pilot study are to explore the toxicities, QOL and efficacy of focal salvage HDR brachytherapy in patients with MRI-visible biopsy-confirmed local recurrence. Methods: Eligible patients included: multiparametric 3T MRI-visible biopsy-confirmed local recurrence > 30 months after XRT, negative metastatic workup, IPSS < 15, post-XRT PSA < 10ng/mL, prostate volume ≤ 50cc. The ultrasound-based HDR brachytherapy prescription dose was 27Gy divided over two implants separated by 1 week to the target volume (TV) with dose constraints to the urethra and rectum. Follow-up PSA, IPSS, EPIC QOL and CTCAE v4.0 toxicities were collected. Results: 15 patients (mean age 73 years) were enrolled in the study. Median follow up was 30 months (12-42). At initial presentation, there were 5, 8 and 2 low-, intermediate- and high-risk disease, and initial XRT dose was 70-78Gy. The Gleason score of the local recurrence was 6, 7 and 8-10 in 1, 7 and 6, respectively, and not classified in 1 patient. The pre-HDR median PSA was 4.13 (1.30 – 9.29). The median size of the recurrence on MRI was 9mm (7-20), TV 6.1cc (2.2-16.1), TV V100 96.3%, TV D90 110.9%, urethral D10 64.5% and rectal D10 36.0%. No acute/late GU/GI grade 3-5 toxicities, nor urinary retention, were observed. The most common acute toxicity was frequency and nocturia. Median IPSS at baseline, 1-, 3-, 6-, 12-, 18-, 24-months was 4, 8, 5, 5, 8 and 5 (p = 0.72). Three year PSA failure free rate was 71%. There was no significant change in EPIC domains. Conclusions: Early toxicity, QOL and PSA failure-freedata suggests that focal salvage HDR brachytherapy is well tolerated and effective. Clinical trial information: NCT01583920.