ESTRO 2022 - Abstract Book

S1172

Abstract book

ESTRO 2022

Results Patient’s median age was 74 years (range: 53-89), 3.6% of the patients were classified as low risk, 42,7% as intermediate risk, 51,8% as high risk and 1.8% were identified with metastatic disease. No infectious prostatitis after fiducials markers implementation was found. Acute urinary toxicity G2 was observed in 9.3% of patients and G3 in 1,24%. Acute gastrointestinal toxicity G2 and G3, were observed in 18% an 17% of patients respectively. Regarding late toxicity, urinary toxicity G2 was found in 4,5% of patients and 0,75% showed G3 toxicity. Late gastrointestinal toxicity G2 was identified in 3% of patients. No G3 toxicity was recorded. Conclusion Moderate hypofractionated radiotherapy for prostate cancer presented good gastrointestinal and urinary toxicity profile. Furthermore, it reduces treatment time and supposes an advantage of time consuming and efficiency.

PO-1383 Adjuvant versus salvage radiotherapy in patiens with prostate cancer: a monocentric experience

E. Calistri 1 , T. Fuentes 1 , R. Morganti 2 , A. Sainato 1 , B. Manfredi 1 , F. Matteucci 1 , F. Pasqualetti 1 , F. Paiar 1

1 University Hospital of Pisa, Oncological Radiotherapy, Pisa, Italy; 2 University Hospital of Pisa, Statistics Department, Pisa, Italy Purpose or Objective Purpose : A much debated topic in prostate cancer therapy concerns the correct timing of radiotherapy (RT) in subjects undergoing radical prostatectomy. Recently, Radicals-RT trial showed comparable results between patients undergoing adjuvant RT, immediately after surgery, and those undergoing salvage radiotherapy at the time of a biochemical relapse. The purpose of our work is to verify the thesis supported by the RADICALS study in order to investigate the best timing to plan post-operative radiotherapy. Materials and Methods Material and Methods : We conducted a retrospective study on 249 patients with operated prostate cancer (prostatectomy alone or prostatectomy plus lymphadenectomy) divided according to postoperative PSA in three groups: a first group of 40 patients with postoperative PSA> 0.5 ng / ml; a second group of 209 patients with postoperative PSA < 0.5 ng / ml; within this second group there was a further subgroup of 165 patients with postoperative PSA < 0.2 ng / ml. All patients were studied according to the following criteria: Gleason Score, age, type of surgery, risk class, PSA at diagnosis, postoperative PSA, number of lymph nodes removed, pTNM and margin status. From January 2011 to December 2019, all these 249 subjects underwent RT: 158 patients were treated with adjuvant RT (135 only on the prostate lodge and 23 on the lodge and lymph node drainages), and 91 with salvage RT (77 only on the prostate lodge and 14 on prostatic lodge and lymph node drainages). All patients were treated on the prostate bed (70-72 Gy using a standard regimen or 63-65.80 Gy using a hypofractionated regimen) and only selected patients in on lymph node drains chains (50.40 Gy in 28 fractions with possible boost up to 65.80 Gy on positive lymph nodes). The median follow-up was 63 months (Range 18-116 months). Results Results : We did a multivariate analysis of Progression Free Survival factors risk by step-wise method finding: in the group of all 249 patients for those with adjuvant RT group vs rescue RT HR = 3,195 ( 95% CI: 1,534-6,655 with p= 0,002). In the group of PSA < 0.5ng/ml for those with adjuvant RT group vs rescue RT HR= 3,763 ( 95% CI: 1,509-9,380 with p=0,004). In the last group of PSA < 0.2ng/ml, the p-value was 0.35. Conclusion Conclusion : These results show a similar trend between adjuvant RT and salvage RT only in subjects with postoperative PSA < 0.2 ng / ml, while, in other populations, the adjuvant RT has a better outcome. In light of these results, salvage radiotherapy should be planned as soon as the PSA value exceeds 0.2 ng / mL.

PO-1384 Simethicone use to Reduce Rectal Variability During Prostate Cancer Radiotherapy, a Randomised Trial

J. Ward 1 , S. Gill 1 , K. Armstrong 1 , T. Fogarty 1 , D. Tan 2 , A. Scott 3 , A. Yahya 4 , S. Dhaliwal 5 , A. Jacques 6 , C. Tang 1

1 Sir Charles Gairdner Hospital, Radiation Oncology, Perth, Australia; 2 Sir Charles Gairdner Hospital, Radiation Oncology, Perth , Australia; 3 Sir Charles Gairdner Hospital, Radiation Oncology Physics, Perth, Australia; 4 Sir Charles Gairdner Hospital, Radiation Oncology Research, Perth, Australia; 5 Sir Charles Gairdner Hospital, Radiation Oncology Statistics, Perth, Australia; 6 Sir Charles Gairdner Hospital, Department of Research, Perth, Australia Purpose or Objective To assess whether simethicone reduces the rectal volume (RV) and volume of gas in the rectum (GV) in men undergoing image guided radiation therapy for prostate cancer, in order to increase treatment accuracy and decrease toxicity by minimising inter-fraction target volume motion. Materials and Methods This trial was a prospective, single centre, non-blinded, randomised controlled trial. It included patients with prostate cancer undergoing external beam radiation therapy radically to an intact prostate, as well as salvage or adjuvant radiation therapy to the prostate bed, with or without the inclusion of the pelvic lymph nodes. 30 patients were randomised 1:1 to