ESTRO 2020 Abstract Book

S618 ESTRO 2020

PO-1174 Results of a multinational clinical audit for prostate cancer radiotherapy: the IROCA project C. Lopes de Castro 1 , M. Fundowicz 2 , A. Roselló 3 , J. Jové 4 , L. Deantonio 5 , A. Aguiar 1 , C. Pisani 5 , S. Villà 4 , A. Boladeras 6 , E. Konstanty 2 , M. Kruszyna-Mochalska 2 , P. Milecki 7 , D. Jurado-Bruggeman 8 , J. Lencart 9 , I. Modolell 10 , C. Muñoz-Montplet 10 , L. Aliste 11 , M.G. Torras 12 , M. Puigdemont 3 , L. Carvalho 1 , M. Krengli 5 , F. Guedea 6 , J. Malicki 2 1 Instituto Português de Oncologia do Porto Francisco Gentil- EPE, Radiotherapy, Porto, Portugal ; 2 Greater Poland Cancer Centre, Radiotherapy, Poland, Poland ; 3 Institut Català d'Oncologia, Radiotherapy, Girona, Spain ; 4 Institut Català d'Oncologia, Radiotherapy, Badalona, Spain ; 5 Università degli Studi del Piemonte Orientale, 7 Department of Electroradiology- University of Medical Sciences, Radiotherapy, Poznan, Poland ; 8 Institut Català d'Oncologia, Physics, Girona, Spain ; 9 Instituto Português de Oncologia do Porto Francisco Gentil- EPE, Physics, Porto, Portugal ; 10 Institut Català d'Oncologia, Physics, Barcelona, Spain ; 11 Institut Català d'Oncologia, Statistics, Barcelona, Spain ; 12 Institut Català d'Oncologia, Epidemiology, Barcelona, Spain Purpose or Objective The IROCA project (Improving Quality in Radiation Oncology through Clinical Audits) was created to conduct clinical audits among member institutions to assess adherence to good clinical practice. Here we describe the results of the clinical audit of radiotherapy processes for prostate cancer (PCa) at six different European cancer centres in Spain, Portugal, Poland, and Italy. Material and Methods This multi-institutional retrospective cohort study included 240 randomly-selected patients who underwent radiotherapy for PCa. Clinical indicators were evaluated to assess three phases of care: 1) diagnosis and pre- treatment; 2) treatments administered; and 3) follow. Specific indicators included: presentation to multidisciplinary tumour board (MTB) and departmental clinical session (DCS); clinical record keeping; diagnostic tests; clinical trials; time between first visit and starting of radiotherapy; type of treatment administered; dose/fractionation and treatment duration; treatment delays, interruptions, and compensations; radiotherapy technique and image guidance; adjuvant treatment; and registration of adverse effects (AE) and appropriateness of follow-up. Results All audits were performed in the year 2017. We evidenced substantial inter-centre variability in clinical practice, particularly for the following indicators: 1) proportion of patients undergoing staging MRI (range, 27.5%-87.5%); 2) percentage of patients presented to the MTB (range, 2.5%- 100%); days elapsed between the 1st visit to the radiation oncology department and radiotherapy initiation (range, 42-102.5 days); treatment interruptions ≥ one day (range, 7.5%-97.5%). The most common divergence from generally-accepted good clinical practice was inconsistent data registration. Conclusion This multi-centre clinical audit reveals substantial inter- centre variability in clinical practice. Although overall adherence to clinical protocols and practices was strong, several areas amenable to improvement were detected, particularly with regard to data registration. These results show that external clinical audits are invaluable to identify areas of strength and weakness, which can then be used to improve radiotherapy practices. These findings underscore the value of conducting clinical audits and support the greater use of audits in the field of radiation oncology. Radiotherapy, Novara, Italy ; 6 Institut Català d'Oncologia, Radiotherapy, Barcelona, Spain ;

PO-1175 SBRT for localised prostate cancer – Nordic results with mFU of 5.3 years K. Vuolukka 1 , J. Palmgren 1 , E. Tiainen 2 , H. Janne 1 , P. Auvinen 1 , V. Kataja 3 , J. Seppälä 1 1 Kuopio University Hospital, Center of Oncology, Kuopio, Finland ; 2 University of Eastern Finland, Faculty of medicine, Kuopio, Finland ; 3 Central Finland Central Hospital, Administration, Jyväskylä, Finland Purpose or Objective The use of hypofractionated stereotactic body radiotherapy (SBRT) as primary treatment modality in clinically localized prostate cancer (PCa) is emerging. There is a need for more data about the efficacy and toxicity of SBRT, especially in high-risk PCa patients. The purpose of this retrospective study was to up-date the safety and the efficacy results of the first Nordic PCa patient cohort treated with robotic SBRT. Material and Methods During the years 2012-2015, 218 consecutive patients with clinically localized PCa were treated with SBRT to total doses of 35 Gy or 36.25 Gy in 5 fractions using a robotic SBRT device (CyberKnife® VSI). The incidences of grade 3 genitourinary (GU) and rectal (GI) toxicities and overall survival (OS), disease-specific survival (DSS) and biochemical relapse-free survival (bRFS) were analysed. Patients with only one PSA (n=5) after SBRT were excluded from the analysis. Results A total of 213 patients were included to the analysis. The median age was 70 years (range, 47-86 years). The number of patients with a low-, intermediate- and high-risk PCa were 48 (22.5%), 56 (26.3%) and 109 (51.2%), respectively. At the cut-off, the median follow-up (mFU) was 64 months (range, 10-85 months), the OS rate was 91.5%, DSS rate 99.1% and the bRFS rate 87.8%. Efficacy results according to the risk groups are presented in Table 1. The 4-year bRFS rates were 100%, 96% and 96% in low, intermediate and high-risk groups, respectively. There were no significant differences in efficacy parameters according to the total dose or PSA. However, the bRFS correlated significantly to the Gleason Score ( p =0.000), the risk-group ( p =0,012) and the use of ADT ( p =0,006). Table 2 . The incidence of severe (grade 3) GU and GI toxicities were 4.2% (n=9) and 0.9% (n=2), respectively. Table 1. Efficacy results according to D’Amico risk groups.

Table 2. Biochemical relapse-free survival (bRFS) rates in different subgroups at the cut-off.