e16071 Background: To report long term Health Related Quality of Life (HRQoL) in a prospective series of 629 patients with intermediate or high-risk clinically localized prostate cancer treated with either IMRT or IMRT + HDR. Methods: Between December 1999 and December 2010, 629 patients (pts) with PSA›10, Gleason score›6 and/or T2b-T3 N0 M0 prostate cancer entered the study. Pts were prospectively assigned to one of the two treatment groups: 76 Gy HD-3D-IMRT to the prostate in 38 fractions (group 1; 315 patients) or 46 Gy LD-3D-CRT+ 16 Gy HDR-B given in 2 fractions of 8 Gy (group 2, 316 patients), limiting the maximum rectal dose to 85% of the prescribed dose. Both groups were well balanced taking into account patient’s as well as tumors’ characteristics. Toxicities were scored by the EORTC /RTOG morbidity grading scales. Special attention to local, regional or distant recurrence, survival, late effects, PSA and testosterone levels as well as HRQOL was done. Results: All pts completed treatment. None pts included in group 1 or 2 had grade 3 or more rectal toxicity. With a mean follow-up of 96 m, the 8-year free-from-failure survival was 90.7% and 98.3% (p<0.02) in group 1 and 2 respectively; free-from-metastases survival 96.9% and 97.9% (p<0,08)for group 1 and 2; and cause-specific survival 97.4% and 98.3% (p<0.09). HRQoL was evaluated before treatment, at 3 months interval during the first year follow up and in a yearly basis until 10-year. I-PSS and EORTC’s QLQ-C30 with PR-25 were used. I-PSS scores at 1, 3 and 6 months and at 1, 2, 3, 5 and 8 years follow-up were 6.39, 5.00, 2.52, 2.21, 2.35, 3.65 and 1.43 for group 1 pts and 1.50, 1.10, 1.01, 1.05, 0.89, 0.66, 0.67 for group 2 pts. Global HRQoL scores at 1, 3 and 6 months and at 1, 2, 3 and 5 years follow up were 5.56, 5.75, 5.33, 6.00, 5.40, 5.58 and 5.11 for group 1 pts and 5.60, 6.40, 5.78, 5.89, 5.83, 6.37, 6.00 for group 2 pts, being found to be statistically significant at 3 and 5 years follow up (p<0,001 and p<0,024). Conclusions: High-dose 3D-IMRT + HDR brachytherapy was found to be a method of escalating the dose to the prostate that not only increased the chances of cure for patients if not increased their long-term Health Related Quality of Life.