ESTRO 2021 Abstract Book

S1248

ESTRO 2021

Conclusion Delivering SABR to patients with oligometastatic lesions confers high rates of local control as well as overall survival, with minimal toxicity rates. Our data demonstrates real world outcomes for oligo-metastatic SABR similar to that seen in large scale series/clinical trials. The use of SABR in the oligometastatic setting is expected to increase further following its commissioning by NHS England in April 2020. Reference: 1. Chalkidou A, Macmillan T, Grzeda MT, Peacock J, Summers J, Eddy S, Coker B, Patrick H, Powell H, Berry L, Webster G, Ostler P, Dickinson PD, Hatton MQ, Henry A, Keevil S, Hawkins MA, Slevin N, van As N. Stereotactic ablative body radiotherapy in patients with oligometastatic cancers: a prospective, registry-based, single-arm, observational, evaluation study. Lancet Oncol. 2021 Jan;22(1):98-106. PO-1524 On how COVID-19 has affected radiation therapy treatments E.M. Ambroa Rey 1 , D. Navarro 1 , T. Valdivielso 1 , M. Lizondo 1 , T. Ramírez 1 , Á. Infestas 1 , J. García-Miguel 1 , Ú. Gallardo 1 , A. Peralta 1 , D. Amat 1 , G. Frontera 2 , A. López 1 , R. Pujol 1 , M. Parcerisa 1 , M. Colomer 1 1 Consorci Sanitari de Terrassa, Medical Physics Unit, Radiation Oncology Department, Terrassa (Barcelona), Spain; 2 Consorci Sanitari de Terrassa, Medical Physics Unit, Radiation Oncology Department , Terrassa (Barcelona), Spain Purpose or Objective Cancer diagnostics and surgery have been disrupted by the response of health care services to the coronavirus disease pandemic. With the COVID-19 irruption in 2020, some radiotherapy treatments were omitted, delayed, changed intent or shifted to a hypofractionated scheme. The purpose of this study is to investigate the effect, direct or indirect, that COVID-19 has had on radiotherapy treatments in comparison with previous years. Materials and Methods All treatments from 2018 (1521), 2019 (1498) and 2020 (1613) were analysed. Treatments were separated into two categories regarding treatment intent: curative or palliative. Moreover curative treatments were classified by site or pathology: H&N, lung, rectum, prostate, breast, central nervous system (CNS), gynaecological, SBRT and other sites. Percentage of hypofractionated treatments per year (for those with curative intent) was also taken into account. Results Regarding treatment intent, we have found that the number of palliative treatments was similar to previous years: 38% in 2020, 37 % in 2018 and 35% in 2019. Figure I shows the percentage of hypofractionated treatments. During 2020 there were 10% hypofractionated treatments more than 2019, which is more than a threefold increase compared to the growth between 2018 and 2019 (3%).