Abstract Book

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early severe postoperative complications were documented in 5 patients (8%) of RP cohort. Late RTOG grade 3-4 toxicity (urinary and/or intestinal) were recorded in 7 of 63 patients of RR cohort (11.1%) vs. 11 patients of PRT cohort (17.4%) (p=0.05). Conclusion In this matched pair analysis performed in patients with HRPC features at diagnosis, RR achieves better significant biochemical control than RP without significant differences in overall and specific survival. High proportion of patients in RP cohort requires PRT achieving poor rates of biochemical control and being more toxic. PV-0255 Salvage high-dose-rate brachytherapy for previously irradiated locally recurrent prostate cancer M. Galdeano-Rubio 1 , C. Guitérrez-Miguiélez 2 , D. Najjari- Jamal 2 , I. Modolell-Farré 3 , F. Ferrer-Gonzàlez 4 , A. Boladeras-Inglada 4 , R. Gracia-Lucio 3 , J.F. Suárez-Novo 5 , J. Pera-Fàbregas 2 , F. Guedea-Edo 4 1 Hospital Sant Joan de Déu-Fundació Althaia, Radiation Therapy Department, Manresa, Spain 2 Institut Català d'Oncologia - Hospital Duran i Reynals, Radiation Therapy Department - Brachytherapy Unit, Barcelona, Spain 3 Institut Català d'Oncologia - Hospital Duran i Reynals, Medical Physics Department, Barcelona, Spain 4 Institut Català d'Oncologia - Hospital Duran i Reynals, Radiation Therapy Department, Barcelona, Spain 5 Hospital Universitari de Bellvitge, Urology Department, Barcelona, Spain Purpose or Objective External Beam Radiotherapy (EBRT) is considered the standard practice for localized prostate cancer. Although this, local relapses are not uncommon and the ideal savage treatment is not well-defined. We report our outcomes in terms of efficacy and safety of salvage high- dose-rate brachytherapy (HDR-BT) for locally recurrent prostate cancer (LRPC) after definitive radiation therapy (RT). Material and Methods From august 2004 to december 2016 we retrospectively analyzed 96 patients undergoing HDR-BT after pathological confirmation of LRPC. The median age at diagnose was 67 years (55-78) and, the median PSA was 4’1 ng/ml (1’27-19). Gleason score and T scale were 7 and T2, respectively. Prescribed total dose was 38Gy. Patients received 4 fractions of 9’5Gy with 2 implants spaced 2 weeks. The 6% of the patients received previous hormonal therapy (HT) and 11% received adjuvant HT. Biochemical failure (after receiving both primary EBRT and/or BQT) was based on Phoenix definition. Acute and late genitourinary and gastrointestinal toxicities were documented based on Common terminology criteria for adverse events (v4.0). Median follow-up after HDR-BT was 44 months (3-138 months). Results At the time of this study the 3 and 5-year biochemical relapse free rate were 61% (74-42, 95% CI) and 31% (45- 17, 95% CI) respectively. The 5-year local and regional relapse rate were 21% (33-8, 95% CI) and 16% (26-6, 95% CI) respectively. The 5-year systemic relapse rate was 18% (30-6, 95% CI). The 5-year disease free survival was 54% (68-40, 95% CI). The 5-year cancer specific survival rate was 94% (100-88, 95% CI). Late genitourinary Grade 3 and 4 were 12% and 2% respectively, including 8 prostate necrosis. 18 patients required urinary catheter, five required transurethral resections and 2 required cistocath. Conclusion Salvage prostate HDR-BT is an effective modality for LRPC after EBRT although toxicity is not negligible. We propose lower total doses for further treatments and a

Conclusion DCE-MRI is superior to T2W and DWI MRI in defining areas of recurrence within the prostate gland in patients previously treated with radiotherapy, particularly i125 permanent seed implant patients. DCE-MRI should be used to target biopsy and in treatment planning for partial gland salvage therapies. PV-0254 Matched-paired analysis of radical radiotherapy vs. prostatectomy in high-risk prostate cancer M. Cambeiro 1 , F. Diez-Caballero 2 , M. Gimeno Morales 1 , M. Basterra 1 , J. Aristu Mendioroz 1 , M. Moreno-Jimenez 1 , L. Arbea 1 , R. Martinez-Monge 1 1 Clinica Universitaria de Navarra, Radiation Oncology, Pamplona, Spain 2 Clinica Universitaria de Navarra, Urology, Pamplona, Spain Purpose or Objective The aim of the study was to compare oncologic outcomes, postoperative complications and late radiation toxicity in patients with initial PSA ≥20 ng/ml or Gleason >8 in trans-rectal biopsy or both in patients treated with radical radiotherapy (RR) or radical prostatectomy (RP). Material and Methods From 2001 to 2012 two prospective studies with RR were applied in high risk prostate cancer (HRPC) achieving prostate doses Eq2Gy (α/β = 1.2) of 89 & 110 Gy respectively through high dose rate brachytherapy combined with external beam radiotherapy & 2-3 years of androgen deprivation therapy (ADT). These patients were matched 1:1 with those whom underwent RP during the same period. Matching criteria were initial PSA ≥20 ng/ml, trans-rectal diagnostic biopsy Gleason ≥8 and age. Biochemical failure was defined as Phoenix criteria (nadir plus 2) in RR and PSA > 0,2 ng/ml in RP. Acute and late radiation toxicity was evaluated according to RTOG scoring system and also early postoperative severe complications were documented in RP cohort. Cox regression, Kaplan-Meier curves and log-rank tests were performed to assess differences in different end points and toxicity. Results Records of 401 patients in RR and 157 patients in RP cohort were reviewed. Finally, 126 patients that meet matching criteria were analyzed 63 in RR and 63 in RP cohort. The median follow up was 93 months (range 15- 180m), 88 months for radical RR (range 75-93m) and 106 for RP cohort (96-117m) (p=0.017). The 5-10 years actuarial biochemical, pelvic and distant control rates in RR vs. RP cohorts were (87%, 69% vs. 45%, 39% p=<0.001), (96%, 94% vs. 86%, 83% p=0.078) and (82%, 82% vs. 90%, 88% p=0.924) respectively. The 5-10 years actuarial overall and specific survival rates in RR vs. RP cohorts were (96%, 81% vs. 95%, 88% p=0.382) and (93%, 81% vs. 79%, 77% p=0.249) respectively. Postoperative radiotherapy (PORT) due to positive margins, extracapsular extension or both it would be indicate in 40 patients (63%). However, pelvic radiotherapy (PRT) was delivered in 24 (38%), 13 as PORT (20.6%) and 11 as salvage due to biochemical failure (17.5%) reaching a 5-year biochemical control rate in PRT of 22%. Acute RTOG grade 3-4 toxicity (urinary and/or intestinal) were recorded in 1 of 63 patients of RR cohort (1.5%) and