ESTRO 2020 Abstract Book

S630 ESTRO 2020

Actuarial probability of remaining free from biochemical progression was 85% at 3 years and 79% at 5 years. Actuarial probability of freedom from local or pelvic nodal relapse / intra-pelvic nodal relapse at 5 years was 96% / 97% respectively. The majority (15 of 18) biochemical relapses occurred in the GS 8 and above group. Actuarial probability of biochemical control / freedom from distant metastases at 5 years was 90% / 93% for GS 7 or less vs 70% / 75% for GS 8 and above. (Log rank p 0.015 and 0.043 respectively). Actuarial probability of biochemical control / freedom from distant metastases at 5 years was 90% / 96% for Orchidectomy vs 70% / 75% for Medical ADT. (Log rank p 0.009 and 0.009 respectively). Gleason score and ADT method remained independent predictors of outcomes on multivariate analysis. Actuarial probability of freedom from occurrence of grade 2 + GI toxicity was 98% at 2 years and 90% at 5 years post RT. 35% of patients had undergone transurethral resection of the prostate (TURP) prior to RT. TURP was a statistically significant predictor of late GU toxicity: The actuarial probability of freedom from occurrence of grade 2+ GU toxicity at 2 years and 5 years was 82% and 61% for those who had undergone TURP prior to RT versus 94% and 87% for those who had not. (log rank p =0.001) Conclusion Long term outcomes with HypoRT are at par with reported outcomes with standard fractionation in high risk disease. Failures were driven by distant metastases. Gleason score and method of ADT were predictors of outcomes. Late GI morbidity rates were on par with reported literature. Patients who had undergone TURP prior to RT had worse late urinary morbidity. PO-1197 Short-term high precision RT for early PCa with SIB to the DIL: QoL assessment (AIRC IG 13218) G. Marvaso 1 , S.G. Gugliandolo 1 , G. Corrao 1 , S. Volpe 1 , G. Riva 1 , D.P. Rojas 1 , D. Zerini 1 , M. Pepa 1 , P. Pricolo 2 , S. Alessi 2 , G. Petralia 2 , F. Cattani 3 , O. De Cobelli 4 , R. Orecchia 5 , B.A. Jereczek-Fossa 1 1 IEO- European Institute of Oncology IRCCS, Division of Radiotherapy, Milan, Italy ; 2 IEO- European Institute of Oncology IRCCS, Division of Radiology, Milan, Italy ; 3 IEO- European Institute of Oncology IRCCS, Medical Physics Unit, Milan, Italy ; 4 IEO- European Institute of Oncology IRCCS, Division of Urology, Milan, Italy ; 5 IEO- European Institute of Oncology IRCCS, Scientific Directorate, Milan, Italy Purpose or Objective As part of the AIRC IG-13218, registered at ClinicalTrials.gov as NCT01913717, we analyzed data from 65 prospectively enrolled patients with low and intermediate risk prostate cancer treated with extremely hypofractionated radiotherapy (RT) to identify clinically meaningful information through the analysis of validated questionnaires testing gastrointestinal (GI) and genitourinary (GU) RT related toxicity and their impact on After the end of RT treatment, clinical assessment and prostate-specific antigen (PSA) measurements were performed every 3 months for at least 2 years. GI and GU toxicities were scored according to Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer (RTOG/EORTC) scoring criteria. QoL of enrolled patients was assessed by the International Prostatic Symptoms Score (IPSS), Quality Life Questionnaire - Core 30 (QLQ-C30), QLQ for prostate specific (QLQ-PR25) and sexual activity by the International Index of Erectile Function (IIEF-5). Within- patient score changes of questionnaires were calculated at quality of life (QoL). Material and Methods

Conclusion According to recent published studies, our data confirmed the excellent outcomes of pN1 PCa patients treated with adjuvant treatments. The significant beneficial effect of aRT on cancer-specific outcomes is supported by a low- grade of acute and chronic of toxicities. Moreover, we confirmed the key role represented by the number of positive nodes in predicting b-PFS, c-PFS and m-PFS. These results support the need of perspective, randomized, larger cohort studies to individuate the number of positive nodes which benefit aRT in order to choose the best adjuvant personalized treatment. PO-1196 long term results with moderately hypofractionated RT in high-risk localized prostate cancer. S. Maulik 1 , I. Mallick 1 , M. Arunsingh 1 , S. Chatterjee 1 , R. Achari 1 , S. Chakraborty 1 , B. Arun 2 , S. Prasath 2 1 Tata Medical Centre- Kolkata, Radiation Oncology, Kolkata, India ; 2 Tata Medical Centre- Kolkata, Medical Physics, Kolkata, India Purpose or Objective We report 5 year disease control and late toxicity outcomes of high risk localized prostate carcinoma treated with long-term androgen deprivation therapy and HypoRT. Material and Methods Patients with high risk localized prostate cancer were treated with a HypoRT regimen of 60 Gy/20#/4 weeks to the prostate and seminal vesicles with simultaneous elective irradiation of pelvic nodal volumes to a dose of 44 Gy/20#. Androgen deprivation therapy comprised of either orchidectomy or medical ADT (total duration of two to three years) starting at least three months before radiation therapy. The outcomes of the first 100 patients treated with this regimen were audited. The predictors of biochemical failure and distant metastases were analyzed. Late toxicity was graded using a modified version of the LENT SOMA scale Results The cohort of 100 consecutive patients completed RT between March 2012 and September 2015. Median follow up was 61 months. The crude number of biochemical relapses documented was 18. Re-staging at biochemical failure revealed distant metastases in 12 patients. Eight of 12 distant relapses involved non regional lymph nodes, and 5 of these were non regional adenopathy alone.