MP80-19 EVALUATION OF THE « QUADRELLA » AT 2 YEARS: NEW INDEX FOR FUNCTIONAL AND ONCOLOGY PERFORMANCE SPECIFIC TO PROSTATE BRACHYTHERAPY.

INTRODUCTION AND OBJECTIVES: To assess the oncological and functional outcome after prostate brachytherapy (PB), a "Quadrella" index, has been recently developed (Radiother Oncol, 2014: 110-113).We aimed to evaluate this "Quadrella": survival, erectile function, urinary and rectal toxicity at 1 and 2 years.METHODS: From 08/2007 to 01/2013, 193 patients underwent 125I PB (loose seeds, realtime planning, prescribed dose 160 Gy), for a low-risk or favorable intermediate-risk adenocarcinoma (PC).Inclusion criteria were: low risk PC, with no incontinence (initial score ICS¼0), and good erectile function (IIEF5 score >16).One hundred patients met the criteria (mean age: 64y), including 10 patients who had neoadjuvant hormotherapy (to obtain reduction volume: <60cc).Postimplantation intake of phosphodiesterase inhibitors (IPDE5) was not considered as exclusion criteria.PSA testing, ICS and IIEF5 scores were obtained before PB (or hormonotherapy) and at 1 year and 2 years post-PB.Achieving the "Quadrella" was defined: by the absence of biochemical recurrence (Phoenix criteria), no significant erectile dysfunction (IIEF5 >16), the absence of urinary toxicity (IPSS <15 or IPSS> 15 with ?IPSS <5) and no rectal toxicity (RTOG ¼ 0).RESULTS: At 12 months (Table ,figure 1), 91 patients were evaluable and among them Quadrella objective was achieved in 34 patients (37.4%) who met all criteria.In 57 patients (62.6%), all the criteria of Quadrella were not obtained and the main criteria for failure were: erectile dysfunction (ED) in 80.7% of cases (46/57), (the only cause in 32/57¼56.1%).The rectal toxicity (RT) was involved in 33.3% (19/57) and urinary toxicity (UT) in 15.8% (9/57).At 24 months (Table ,figure 2), (n¼86), 40.7% of patients (35/86) responded to Quadrella.Among the 51 cases of failure (51/86¼59.3%),the main causes were: ED at 72.5% (37/51), RT at 39.2% (20/51) and UT at 13.7% (7/51).CONCLUSIONS: The Quadrella can be used at 1 and 2 years after PB for oncological and functional early results.It allows, at the difference of the trifecta, to take into account urinary and rectal toxicity specific to BT when compared to radical prostatectomy.Erectile dysfunction was the main cause of failure for Quadrella PB.This index will be useful to assess mid-term and long-term results with longer follow-up.