ESTRO 2021 Abstract Book

S1099

ESTRO 2021

three are alive. Maximal acute genitourinary (GU) toxicities were grade 1 in 93% and grade 2 in 7% of patients. Maximal acute gastrointestinal (GI) toxicities were grade 1 in 93 patients and 2 observed in 7% of patients. There was no grade 3, 4 or 5 acute GU-GI toxicity. Late toxicities were evaluated in all patients. Grade 1 and grade 2 late GU toxicities were 30% and 70% respectively. Maximal late GI toxicity were grade 1 in 2% of patients. There was no grade 3 or greater late GU and GI events. No relationship was found between GU or GI adverse effects and any of the analyzed parameters: age, androgen deprivation or median PTV volume and median bladder volume (cm 3 ). Analysis data according to RT intention, shows that a GU late toxicity >2 appeared in the 10 % of patients in the adjuvant setting and in 10 % of patients in the salvage group. Only in two patients the post-radiation urinary incontinence got worse, up to grade 3, as compared with baseline. Conclusion Moderate hypofractionated radiotherapy (62.5 Gy in 25 fractions at 2.5 Gy/ fraction) post-prostactectomy is well tolerated with an excellent late toxicity profile. PO-1338 Does frailty influence treatment intent in men with non-metastatic prostate cancer? K. Connors 1 , A. Vickers 1 , R. Conroy 1 , C. Coyle 1 , A. Hudson 1 , J. Logue 1 , M. Serra 1 , A. Tran 1 , H. Mistry 2 , J. Wylie 1 , A. Choudhury 3 , Y.P. Song 1 1 The Christie NHS Foundation trust, Clinical oncology, Manchester, United Kingdom; 2 The University of Manchester , Division of cancer sciences, Manchester, United Kingdom; 3 The university of Manchester, Division of cancer sciences, Manchester, United Kingdom Purpose or Objective Prostate cancer (PCa) is the most common cancer affecting men in the UK, with 35% of cases being diagnosed in those 75 or over. Given the typically elderly cohort of patients, the degree of comorbidity and frailty is high, which may influence treatment decisions. With the introduction of Clinical Frailty Scale (CFS) as part of routine new patient assessment in addition to ECOG performance status (PS) and ACE-27 comorbidity score, this study aims to assess the correlation between different measure of frailty and comorbidity, and clinician treatment intent. Materials and Methods This is a prospective study of all non-metastatic PCa referrals to a tertiary oncology centre from July to August 2020. Demographic and clinical data were collected. Frailty and comorbidity status were assessed with 3 scoring systems – CFS, PS and ACE-27 comorbidity score. Scores were compared to the clinician documented treatment intent using logistic regression analysis. We assessed for correlation between the three measures of frailty and probability of receiving curative intent with univariable logistic regression analysis with R v3.6.0. Results Data was collected for 113 patients with a median age of 70 (48-84). All patients had documented PS and ACE- 27. 77 patients had documented PS, ACE-27 and CFS scores. PS 2 patients were less likely to be offered curative treatment versus those with PS 0 (OR 0.02; 95%CI 0.01-0.64 p=0.02). PS 1 patients were as likely as PS 0 patients to be offered curative treatment (OR 1.00; 95% CI 0.01-NR; p=0.997). There was no correlation between either ACE-27 or CFS with intent of treatment offered. This is summarised in table 1.

Conclusion Randomised controlled trials show that frailty scores are useful for chemotherapy decisions compared to known prognostic factors and are associated with treatment toxicity. This study shows that men with PS ≥2 are less likely to be offered treatment with curative intent while CFS and ACE-27 did not appear to impact treatment decisions. While the impact of PS on treatment plan is expected, the lack of correlation with CFS and ACE-27 is interesting. The difference in influence of PS and CFS on clinician treatment decision may reflect a lack of familiarity with CFS. Future work will evaluate this finding in a larger cohort of men, with a particular interest in its impact on treatment related toxicities. This study is the first to assess utility of all 3 scores in men having prostate radiotherapy. Data collection continues and further analyses of associations between PS, CFS and ACE-27 and their impact within a multivariable analysis with known prognostic factors is required to establish the importance of these assessments when making treatment decisions.

PO-1339 Estimated late toxicities with pelvic nodal irradiation in prostate cancer: Protons vs Tomotherapy