ESTRO 2020 Abstract Book

S287 ESTRO 2020

comprised patients who had RT for BM at the EOL (defined as death within 30 days of commencing RT). The primary outcome was the proportion of patients who received single fraction RT (SFRT) and multi-fraction RT (MFRT). The Cochrane Armitage test for trend was used to evaluate changes in SFRT use over time. Multivariable logistic regression was used to assess factors associated with SFRT use. Results A total of 8,153 patients received 13,947 courses of palliative RT between 2013 and 2016, of which 1,359 courses of RT were delivered at the EOL. Of these, 396 courses of RT (29%) were SFRT and 963 (71%) were MFRT. There was no significant change in the use of SFRT over time from 30% in 2013 to 32% in 2016 (P=0.07). Patients who had SFRT were older (mean age 71.7 who had SFRT vs. 70.1 who had MFRT; P=0.02). There were no differences in SFRT use for different primary cancer type (P=0.9). SFRT were less commonly given to the skull (6%) compared to other body sites e.g. rib (51%) and extremities (52%) (P<0.001). There was higher use of SFRT in patients who had died shortly after commencing RT – 49%, 29% and 25% in patients who died within 7 days, 8-14 days, and 15-30 days of starting RT respectively (P<0.001). There were large institutional provider variations in SFRT use – 34% SFRT use in public compared to 19% in private institutions (P<0.001), and 35% SFRT use in regional compared to 27% in metropolitan centres (P=0.008). In multivariate analyses, the target RT sites, time between starting RT and death, and institutional type (public/ private) were independently associated with SFRT use. Conclusion This large Australian population-based study showed that less than one-third of palliative RT for BM at the EOL was SFRT. There is variation in SFRT use at the EOL depending on the target body sites, and institutional provider factors. Future work is needed to increase uptake of SFRT use especially in cancer patients with limited prognosis who may require palliative RT for symptom management for BM. PH-0524 “TEACHH” model. Our experience in handling. C. Escuin Troncho 1 , A. Miranda Burgos 1 , C. García Aguilera 1 , M. Cerrolaza Pascual 1 , V. Navarro Aznar 1 , A. Campos Bonel 1 , J. Lao 2 , R. Ibañez Carreras 1 1 Hospital universitario Miguel Servet, Radiation Oncology, zaragoza, Spain ; 2 Hospital universitario Miguel Servet, Oncology, zaragoza, Spain Purpose or Objective Radiation therapy is an effective treatment in symptomatic patients (metastatic bone pain, hemorrhages or cerebral edema). A notable percentage of patients who arrive at a radiotherapy oncology service and are planned do not receive treatment due to worsening general condition or death. It is important to estimate the life expectancy in order to adapt the appropriate decision making regarding the treatment with radiotherapy in these patients. OBJECTIVE: To make a scale of assessment of the prognosis that helps us decide on the importance of the indication of palliative radiotherapy and thus reduce the rate of planned patients who do not receive treatment. Material and Methods After reviewing the literature, we adopted the TEACHH model as a support tool for decision making in palliative radiotherapy. The TEACHH model divides patients into three groups according to life expectancy (1.7; 5 and 19.9

months) based on the score obtained according to the clinical characteristics of the patient (type of cancer, ECOG, age, more of two lines of chemotherapy treatment, previous hospitalizations and the presence of liver metastases). We decided to use the TEACHH model in all hospitalized patients and who present a priori indication of palliative radiotherapy. Results We selected 258 candidate patients for palliative radiotherapy. Radiation therapy was indicated for metastatic bone pain in 38.91% of patients, with haemostatic intention in 10.89%, brain metastases in 22.96%, and finally, for compression of the spinal cord in 17.24% of patients. The remaining 10% were treated for other causes. Of the total patients assessed, 21.77% were in the life expectancy group of 1.7 months; 74.15% in 5 months and 4.08% in 19.9 months. The use of the model allowed us to refuse treatment in 68 (26.46%) patients (30 in the 1.7 month group, 37 in 5 months and 1 in 19.9 months). We planned 31 (12.06%) patients who did not receive death treatment (4 in 1.7 months and 27 in 5 months). Conclusion It is a tool that allows us to administer a palliative treatment or reject it in an adjusted way to each patient taking into account their life expectancy, as well as reducing the rate of untreated planned patients by improving the use of the resources of our service. PH-0525 Radio-immunotherapy versus immunotherapy alone – tolerance and adverse events M. Trommer 1,2,3 , S. Marnitz 1,2,3 , J. Kinsky 1 , A. Adams 4 , M. Hellmich 4 , E. Celik 1 , J.M. Herter 1,3,5 , J. Morgenthaler 1,3 , M. Von Bergwelt-Baildon 2,6 , M. Schlaak 2,7 , S. Theurich 2,6 , C. Baues 1,2,3 1 University Hospital of Cologne, Department of Radiation Oncology, Köln, Germany ; 2 University Hospital of Cologne, Radio Immune-Oncology Consortium RIO, Köln, Germany ; 3 University Hospital of Cologne, Center for Integrated Oncology CIO, Köln, Germany ; 4 University of Cologne- Medical Faculty, Institute of Medical Statistics and Computational Biology, Köln, Germany ; 5 University of Cologne, Center for Molecular Medicine Cologne CMMC, Köln, Germany ; 6 University Hospital- LMU Munich, Department of Medicine III, München, Germany ; 7 University Hospital- LMU Munich, Department of Dermatology and Allergology, München, Germany Purpose or Objective Immune checkpoint inhibition (ICI) has changed oncologic treatment strategies dramatically. Both monotherapy and combination therapies have established themselves not only in the metastatic situation to optimize the effect on the tumor. Radiotherapy (RT) is a highly effective local treatment. Especially local but also systemic adverse events due to RT are well known. The mechanisms by which RT and ICI synergistically modulate the immune response might also affect treatment-related side effects. Severe adverse events due to ICI (CTCAE v.5.0 Grade 3-4) are reported in 17-21% of the patients receiving monotherapy. In this study we retrospectively analyzed patients being treated with PD-1 inhibitors (PD-1i) alone or with additional RT regarding the tolerability of this

combination concept. Material and Methods

We screened all patients treated with PD1i at our center between 2013 and 2017 and divided the patients into 2 different treatment groups with (RIT = radio- immunotherapy) or without (IT = immunotherapy alone)