ESTRO 2022 - Abstract Book

S1181

Abstract book

ESTRO 2022

Results All calculated radiotherapeutic plans, regardless of CTV delineation and margin expansion, met OAR DVH constraints, while at the same time achieving adequate target coverage, as suggested by the CHHiP trial protocol. TCP calculation was >99% for all plans and all cases. NTCP investigations revealed no statistically significant differences. Conclusion Data based on dosimetric and radiobiological comparisons demonstrate that our simpler institutional delineation protocol is at least as effective in regard to PTV coverage, and as safe in regard to OAR sparing, as the validated CHHiP trial PTV definition.

PO-1394 Adjuvant radiation therapy after radical prostatectomy

V. DUQUE SANTANA 1 , J. Domínguez Rullán 2 , A. Hervás Morón 3 , F. López-Campos 2 , C. Vallejo Ocaña 2 , M. Valero Perena 4 , M. Martín Martín 2 , D. Sevillano Martínez 5 , J.D. Garcia Fuentes 5 , S. Sancho García 2 1 Ramon y Cajal University Hospital, Radiation Oncology , Madrid, Spain; 2 Ramon y Cajal University Hospital, Radiation Oncology, Madrid, Spain; 3 Ramon y Cajal University Hospital, Radiation Oncology, Madrid , Spain; 4 Ramon y Cajal University Hospital, Radiation Oncology, MAdrid, Spain; 5 Ramon y Cajal University Hospital, Physics, Madrid, Spain Purpose or Objective The purpose of the study is to analyze the results of adjuvant radiotherapy after radical prostatectomy and to determine prognostic factors of biochemical relapse free survival (BRFS). Materials and Methods 120 consecutive patients were treated between 1997 and 2014 at our institution. Overall survival and biochemical relapse free survival were calculated using Kaplan-Meier method and the COX proportional hazard test was used to assess differences between groups. We also analyse the possible associations between the quantitative and qualitative variables by Student's T analysis or the chi-squared test (x2). Results Mean age at diagnosis was 65 years (42-80). 51 (42.5%) patients were Gleason ≤ 6, 56 (46.7%) patients were Gleason 7 and 13 (9.7%) patients were Gleason ≥ 8. 55 (45.9%) patients underwent radical prostatectomy combined with pelvic lymphadenectomy and 65 (54.1%) patients underwent radical prostatectomy without pelvic lymphadenectomy. 12 (10%) patients had negative surgical margins, 104 (86.6%) patients had positive surgical margins and 4 (3.3%) close surgical margins. 15 (12.5%) patients were treated with neoadjuvant hormone therapy. 60 (50%) patients were pT2, 53 (44.2%) were pT3 and 7 (5.8%) were pT4. Adjuvant RT was performed in all patients. 23 (19.2%) patients received <70Gy and 97 (80.8%) received ≥ 70Gy. 19 (16.1%) patients experienced biochemical relapse. 8 (6.7%) developed local relapse. 14 (11.7%) developed nodal relapse. 11 (9.2%) developed metastatic relapse. After a median follow-up of 114 months (10-239 months). Overall survival at 5 and 10 years were 94.0% and 83.1%, respectively and BRFS at 5 and 10 years was 85.4% vs. 83.2%%, respectively. Gleason at diagnosis was a significant prognosis factor of BRFS (p=0.003) and radiotherapy at dose > 70Gy was not related with a better BRFS (p=0.830) Conclusion Postoperative radiation therapy provides excellent long-term overall survival with good biochemical relapse free survival. Dose escalated radiotherapy up to >70Gy doesn´t improve the biochemical relapse free survival in these patients.

PO-1395 Impact of Statin Use on Biochemical Failure following Radical Prostatectomy or Radiation Therapy

L. Huynh 1 , E. Keit 1 , R. Carrillo 2 , E. Huang 2 , T. Ahlering 2 , S. Boyle 3,3 , C. Enke 1 , M. Baine 4

1 University of Nebraska Medical Center, Radiation Oncology, Omaha, USA; 2 University of California Irvine, Urology, Orange, USA; 3 University of Nebraska Medical Center, Urology, Omaha, USA; 4 University of Nebraska Medical Center, Radiation oncology, Omaha, USA Purpose or Objective To assess the impact of statin use on overall and time to biochemical failure following primary treatment of localized prostate cancer (PC) Materials and Methods 1,581 patients undergoing radical prostatectomy (RP) or radiation therapy (RT) for primary treatment of PCa between July 2007 and January 2020 were evaluated for statin use, demographic/oncologic characteristics, and biochemical outcomes. Rate of biochemical failure (BF) was assessed overall and at 1, 3, and 5 years; time to BF was estimated with Kaplan-Meier. Logistic and linear regression were used to control for treatment modality and disease characteristics.