ESTRO 2022 - Abstract Book

S1190

Abstract book

ESTRO 2022

Purpose or Objective To analize clinical results of radiotherapy treatment after radical prostatectomy for prostate cancer and to determinate prognostic factors of biochemical relapse free survival (BRFS) and overall survival.

Materials and Methods We review the records of patients treated in our institution with postoperative radiotherapy (adjuvant and salvage radiotherapy indication according to international guidelines definition) after radical prostatectomy. Overall survival and biochemical-relapse free survival were analized using Kaplan-Meier and Cox regression analysis was used to assess differences between groups. Results 287 patients were treated at our institution over a 12-year period. Mean age at diagnosis was 64 years (41-75). All patients underwent radical prostatectomy combined with pelvic lymphadenectomy in 48.6% of cases. Neoadjuvant androgen deprivation before surgery was given to 35.6% . Median pre-RT PSA of 0.41ng/ml (0-12.8 ng/ml). Adjuvant RT (ART) was performed in 120 patients and salvage RT (SRT) in 168. Doses to surgical bed were ≥ 70 Gy (70-76 Gy) in 78.8% of patients and 66 Gy in 20.8%. The distribution of patients by pT stage was pT2a/b (29%), pT2c (37.1%), pT3 (28%) and pT4 (2.4%). Upgrade in Gleason Score between transrectal biopsy and prostatectomy was experienced by 46.7% of patients. Positive surgical margins were reported in 58.4% of cases. Mean follow-up was 146.7 months (10-289 months). Overall survival at 5 and 10 years was 97.1% and 85.5%, respectively and BRFS at 5 and 10 years was 83.4% vs. 79.9%, respectively. No differences in BRFS between ART and SRT or doses to surgical bed were found. Gleason score, T stage and PSA levels before RT were significant predictors of BRFS.

Conclusion Postoperative radiation therapy provides excellent long-term overall survival results with an aceptable BRFS. Lower PSA levels before radiotherapy is a predictor of better outcomes. Early salvage and maderate doses are highly recommended.

PO-1404 Adjuvant, Early Salvage and Salvage Radiotherapy after surgery in prostate cancer: survival outcomes

I. Angelicone 1 , A. Priore 1 , F. Perrone Congedi 1 , F. de Giacomo 1 , B. Campanella 1 , M.F. Osti 1 , M. Valeriani 1

1 Sapienza Università, A.O.U. Sant'Andrea, U.O. Radioterapia Oncologica, Roma, Italy

Purpose or Objective Endpoints of this retrospective study in terms of clinical outcomes were Overall Survival (OS), Biochemical-Free Survival (BFS) and Radiological Progression Free Survival (RPFS) of patients (pts) with histologically confirmed prostate cancer treated with post-operative radiotherapy after radical prostatectomy. Materials and Methods Our casistic involved 154 pts with a median age of 65 years (range 49-79), underwent adjuvant (36%), early-salvage (30%) and salvage radiotherapy (34%) between March 2011 and March 2020. RT was performed with Intensity Modulated Radiotherapy (IMRT)/Volumetric Modulated Arc Therapy (VMAT) technique and dose varied from 62.5 to 70 Gy. Pts with a PSA value after surgery under 0.2 ng/dL and unfavorable histopathological characteristics (neoplastic invasion of seminal vesicles or extracapsular extension of neoplasm) were assigned to receive Adjuvant Radiotherapy (ART), pts with a PSA value between 0.2 and 0.5 ng/dL were treated with Early Salvage Radiotherapy (ESRT) and pts with a PSA value over 0.5 ng/dL or positive surgical margins received Salvage Radiotherapy (SRT). Univariate analysis (log rank) were assessed with Chi-square test and Kaplan-Meier method. Results Median follow-up was 70.3 months (range 11.3-121.4). OS at 5 and 8 years was 95.5% and 84.3% respectively for all pts included, with significant statistical difference (p=0.043) between pts treated with ESRT (OS at 5 and 8 ys = 97,7%) and SRT (OS at 5 ys = 95.5%; at 8 ys = 70.8%). BFS in the whole population was 71% at 5 years and 68,3% at 8 years, with a statistically significant difference (p=0,011) between pts treated with ART (BFS at 5 and 8 ys = 82.2%) and SRT (BFS at 5 ys = 61.3%; at 8 ys = 58.5%). RPFS was 85.7% at 5 years and 83.4% at 8 years: the same results were observed also in this case, with a statistically significant difference between pts treated with ESRT (RPFS at 5 and 8 ys = 95.7%) and SRT (RPFS at 5 ys = 73.3%; at 8 ys 67.3%; p=0.03). Conclusion Our analysis demonstrates that patients underwent Adjuvant RT have better survival outcome then patients treated with Salvage RT in terms of biochemical-free survival. A statistically significant difference is also demonstrated between patients treated with Early Salvage RT, that shows an improved overall survival and radiological progression-free survival, and Salvage RT.

PO-1405 Sbrt in prostate cancer: a feasibility and safety annalysis

J.A. Solis Campos 1,2 , J. Olivares Gonzalez 1 , H. Letelier Flores 3 , G. Lazcano Alvarez 1 , I. Perrot Rosenberg 1 , G. Veillon Contreras 1,2 , B. Tudela Staub 1,2 , R. Yañez Davila 3 , C. Herrera Bovet 3 , Y. Guillen Cabrera 3 , G. Rubio Riquelme 4