ESTRO 2020 Abstract book

S663 ESTRO 2020

With a median follow-up of 109 months (range 16-248) for LTL and 108 months (24-210) for NTL (p=ns), 90 patients (38%) with LTL had died compared with 44 patients (16%) in NTL group. The 9-year DFS, OS and CSS for LTL were 76%, 72% and 93% and 94% (p=0.000), 89% (p=0.000) and 99% (p=0.000) in NTL respectively. In the multivariate analysis NTL was a significant predictor of DFS (p=0.000), OS (p=0.004) and CSS (p=0.002), age of OS (p=0.000) and tumour stage and cardiovascular disease of DFS (p=0.018) Regarding our results, patients with long-term LTL had lower survivals and higher cause of death than NTL, in probable relationship with more advanced and aggressive disease at baseline, and older age where competitive comorbidities are also high. PO-1171 Low- and Intermediate-Risk Prostate Cancer. Stereotactic Body Radiation Therapy. Our experience. C. García Aguilera 1 , A. Méndez Villamón 1 , S. Flamarique Andueza 1 , D. Villa Gazulla 1 , C. Escuín Troncho 1 , J.M. Ponce Ortega 1 , M.M. Puertas Valiño 1 , M. Tejedor Gutiérrez 1 1 Hospital Universitario Miguel Servet, Servicio de Oncología Radioterápica, Zaragoza, Spain Purpose or Objective To analyze the survival and toxicity of patients with low and intermediate risk prostate cancer treated with Stereotactic Body Radiotherapy (SBRT) in our center. Material and Methods We retrospectively included patients with low and intermediate risk prostate cancer treated with SBRT between February 2014 and July 2019. We analyzed progression-free survival, prostate cancer-specific survival and actuarial overall survival. To measure toxicity, acute and late, we used the CTCAE 4.0 scale. We analyze 253 patients, 35,6% were low risk and 64.04% intermediate risk. 39,9% had hormonal treatment (analogue LHRH) in short cycle (6 months). We perform simulation CT. To minimize doses in risk organs, the patients was advised dietematically and bladder preparation was performed. The treatment was administered with intensity-modulated radiotherapy using linear accelerator, guided by daily image by megavoltage cone-beam. The dose used was 35Gy in 5 fractions of 7Gy, one day a week on the volume of the prostate. (p=0.038). Conclusion

Meier survival. Cox regression analysis was performed to determine factors influencing BRFS. Results All patients were initially cM0 with mostly high-risk PCa (342/359; 95%). Seventy-five patients had local recurrence within the prostatic fossa, 32 patients pelvic nodal plus local recurrence, 117 patients pelvic nodal recurrence, 51 patients paraaortic lymph node metastases with/without locoregional recurrence and 84 patients had bone or visceral metastases with/without locoregional recurrence. Median PSA before MDR was 1.2 ng/ml (range, 0.04 - 47.5). MDR was either applied as stereotactic body or normo- fractionated EBRT to macroscopic tumor lesions. Additive androgen deprivation therapy (ADT) was given in 35% (125/359) of patients with ongoing ADT at last follow-up in 51% (64/125) of those patients. Median PSA nadir after MDR was 0.23 ng/mL (range, <0.03 - 18.30). After a median follow-up of 16 months (1 - 57), 239/351 (68%) patients had no biochemical recurrence. Patients with distant lymph node and/or distant metastases, the so-called oligo- body cohort, had an overall in-field control of 90/98 (91%) but at the same time an ex-field progress of 44/96 (46%). In comparison, an ex-field progress was detected in 28/154 (18%) patients with local and/or pelvic nodal recurrence (oligo-pelvis group). Compared to the oligo-pelvis group, there was a significantly lower BRFS in oligo-body patients at last follow-up. Conclusion Overall, BRFS was dependent on patterns of metastatic disease. Thus, MDR of PSMA PET-positive oligo-metastases can be offered considering that about one-third of the patients progressed within a median follow-up of 16 months. PO-1170 Long-Term testosterone levels and its influence in treatment outcomes in prostate cancer patients J.L. Munoz Garcia 1 , F. Ropero Carmona 1 , B. Ortiz Sierra 1 , Y. Rios Kavadoy 1 , J. Quiros Rivero 1 , J. Cabrera Rodriguez 1 , P. Simon Silva 1 , B. Baños Perez 1 , C. Corral Fernandez 1 1 Badajoz University Hospital, Radiation Oncology Department, Badajoz, Spain Purpose or Objective Low testosterone levels (LTL) is an objective during ADT but long-term LTL increase the causes of death not related to prostate cancer (PCa). Our objective was to analyse the influence of long-term LTL in treatment outcomes in patients with PCa who underwent External Beam Radiation Therapy (EBRT) and androgen deprivation therapy (ADT). Material and Methods Retrospective comparative study of 536 patients with PCa treated with EBRT+ADT in our hospital from October 2001 to June 2012. In the last follow-up 263 (49%) patients had LTL and 273 (51%) normal testosterone level (NTL). The baseline characteristics of the patients in the sample were significantly different between patients with LTL and NTL. LTL were elderly patients, with higher PSA, more advanced primary tumour stage, risk group, Gleason score, positive cylinder percentage, longer ADT and personal history of diabetes mellitus and cardiovascular disease. The median doses of EBRT doses was 78 Gy for LTL and NTL. Overall survival (OS), Disease free survival (DFS) and Cause specific survival (CSS) were estimated with Kaplan-Meier and compared with Log Rank test. Prognostics factors as age, initial PSA, primary tumour stage, risk group of tumours, Gleason score, positive cylinder percentage, EBRT doses, ADT duration and personal history of mellitus diabetes and cardiovascular disease were related to survivals using Cox regression.

Results