MP70-13 CRYOSURGICAL ABLATION OF THE PROSTATE: LOCAL DISEASE CONTROL FOR INTERMEDIATE /HIGH-GRADE GLEASON PROSTATE CANCER Ahmed El Shafei, Mohamed Eltemamy*, Yaw Nyame, Hans Arora, J Stephen Jones, Cleveland, OH INTRODUCTION AND OBJECTIVES: Our objective is to report local disease control after primary whole gland cryoablation when used to treat Gleason  7 localized prostate cancers at our institution. METHODS: We analyzed 134 prostate cryoablation patients who had a Gleason score of  7 who underwent primary whole gland cryoablation. Progression free survival (PFS) was defined according to Phoenix definition of PSA nadir +2 ng/ml. Among the biochemical failure (BF) patients, we assessed local disease control by postoperative prostate biopsy, pelvic MRI or CT. BS was used to assess metastatic disease. We defined local treatment failure by a positive post cryoa- blation prostate biopsy and/or MRI/CT scan findings suggesting local recurrence within the prostate. RESULTS: PFS was noted in 101 patients (75%) with median follow up time of 31.5 months. Among the 33 patients who showed BF, 3 patients did not have a metastatic workup. Of the remaining 30 pa- tients, 15 (11.2% of treated patients) showed only local treatment failure as indicated by positive post cryoablation prostate biopsy and/or MRI/ CT scan findings suggesting local recurrence within the prostatic gland. The other 15 patients (11.2%) showed metastatic disease with no evi- dence of local treatment failure. (Table 1) CONCLUSIONS: Cryoablation is a successful primary treat- ment option for patients with intermediate/high grade prostate cancer. Up to half of patients who showed biochemical failure had good local disease control but had distant failure as evident by post cryoablation prostate biopsy and/or MRI/CT scans; this suggests patient selection failing to identify micro metastasis present at the time of treatment rather than local treatment failure. Source of Funding: None MP70-14 PSA NADIR AND PSA FLARE ARE THE PREDICTORS OF BIOCHEMICAL FAILURE AFTER HIGH-INTENSITY FOCUSED ULTRASOUND TREATMENT OF LOCALIZED PROSTATE CANCER Naokazu Ibuki*, Teruo Inamoto, Yudai Nishimoto, Kiyoshi Takahara, Toshikazu Watsuji, Haruhito Azuma, Osaka, Japan INTRODUCTION AND OBJECTIVES: High-Intensity Focused Ultrasound (HIFU) is an emerging treatment for localized prostate cancer patients. HIFU is a noninvasive technique that induces coagu- lative necrosis in tumors without surgical exposure or insertion of in- struments into the lesion. We evaluated the association between clinical outcomes and biochemical failure (BCR). METHODS: From June 2006 to November 2014, 259 consec- utive patients with T1-2 prostate cancer were treated with Sonablate? (SB) devices. After HIFU, prostate-specific antigen (PSA) was measured every 3 months. BCR was defined according to the Stuttgart definition (a rise of 1.2 ng/ml or more above the nadir PSA). Serum PSA level was increased rapidly after HIFU. Then, PSA flare was determined an increase of 3.0 ng/ml with a spontaneous return to the pre-flare level or lower. Predictors for BCR was identified using the Cox-proportional hazard method. RESULTS: A total of 259 patients with a median age of 67.6 years were followed for median duration of 59 months. Mean pretreat- ment PSA was 9.6 ng/ml. Mean pretreatment prostate volume was 28.7ml. Stratification according to D’Amico’s risk group was low, inter- mediate, high in 23.6%, 30.5%, 45.9% of patients, respectively. Neo- adjuvant hormone therapy was administered in 45.1% of patients. Transurethral resection of prostate (TURP) at the time of HIFU was performed in 34.4% of patients. Mean PSA nadir was 0.3 ? 0.8 ng/ml with 77.6% reaching nadir of ? 0.3 ng/ml. The overall survival rate at 5 year was 99.6%. The 3- and 5-BCR free survival rates were 72.3- 62.6%, 89.1-78.1%, 72.7-65.0%, 62.6-51.1% for all patients, low- in- termediate-, and high risk patients. 44.1% of patients had urinary structure, 29.7% of patients had self-resolving lower urinary tract syn- drome (LUTS). Cox multivariate analysis revealed Preoperative PSA (PSA cut off ¼ 10 ng/ml: Hazard ratio (HR) ¼ 2.369, 95% CI 1.518e3.735, p<0.001), D’Amico risk group (Low & intermediate vs high: HR ¼ 2.359, 95% CI 1.066-3.086, p¼0.028), PSA nadir (PSA cut off ¼ 0.3 ng/ml: HR ¼ 3.248, 95% CI 1.943-5.427, p<0.001), and PSA flare (PSA cut off ¼ 3.0ng/ml: HR ¼ 2.063, 95% CI 1.014-4.194, p¼0.046) were a predictor for BCR. CONCLUSIONS: HIFU represents an effective, minimally invasive treatment for prostate cancer. The PSA nadir and PSA flare correlate significantly with BCR, and can be applied in daily clinical practice. Source of Funding: none MP70-15 INTRA-PROSTATIC PRX302 FOCAL THERAPY IN TREATING CLINICALLY SIGNIFICANT LOW-INTERMEDIATE PROSTATE CANCER: AN OPEN LABEL, PROOF-OF-CONCEPT STUDY Edward Bass*, Yaalini Shanmugabavan, London, United Kingdom; Allison Hulme, La Jolla, CA; Alex Freeman, Chris Brew-Graves, Ingrid Potyka, Navin Ramachandran, Mark Emberton, Hashim Ahmed, London, United Kingdom INTRODUCTION AND OBJECTIVES: Intra-prostatic injection of PRX302 may provide a targeted approach to focally lysing tumor cells, avoiding the side-effects of radical treatment. It is a genetically modified pore-forming protein (aerolysin) activated by enzymatically active PSA. Our proof-of-concept IRB-approved study aimed to e940 THE JOURNAL OF UROLOGY â Vol. 197, No. 4S, Supplement, Monday, May 15, 2017