ESTRO 2020 Abstract Book

S656 ESTRO 2020

8.9%, kidney 7.4%, bladder 2.9 %. Pain was present before SBRT in 32% of pts with a median value of 5 (3-8), according to Visual Analogue Scale (VAS). Two mg of dexamethasone were prescribed in more than half of pts for 1 week during and after the treatment. In the majority of pts with spinal lesions CT, T1 and T2 MRI were fused and used to outline the gross tumor volume (GTV), to maximize tumor coverage and minimize spinal cord exposure. GTV to planning target volume (PTV) expansion was 2 mm. Median dose prescription was 18 (16-35) Gy, delivered in a median of one fraction (1-7). Results All patients were able to maintain the position during treatment delivery for a median treatment time of 52 minutes (28-83). Median follow-up was 5 (1-17) months. Early pain relief was observed in all symptomatic pts. Only two of 97 patients presented local progression disease. One patient developed G2 acute pain flare toxicity (according to CTCAEv4.03), after one day of dexamethasone suspension. The pain was controlled prolonging dexamethasone for two additional days. In 66 lesions with a follow up longer than 3 (3-17) months, no late toxicities and SBRT-related fractures were observed. Conclusion Our experience with dose intensification in bone metastases is consistent with other published studies, which demonstrated that bone SBRT is a safe treatment providing mild acute and late toxicity profile and early pain relief in all pts. A longer follow up is necessary to confirm the very good local control. R. Asadpour 1 , S.U. Pigorsch 1 , C. Straube 1 , S.E. Combs 1,2,3 1 TU Munich, Department of Radiation Oncology, Munich, Germany ; 2 German Consortium for Translational Cancer Research dktk, Partner Site Munich, Munich, Germany ; 3 Institute of Innovative Radiotherapy iRT, Department of Radiation Sciences DRS- Helmholtz Zentrum München, Munich, Germany Purpose or Objective Radiotherapy (RT) is a main pillar in cancer care. During their course of disease, over 50% of tumor patients are treated with RT, whether in curative or palliative intent. Indication for RT depends on many factors, for example patients’ performance status, life expectancy but also on the expected gain of therapy in terms of palliation. However, due to several factors, early death after RT is observed in some patients. To understand the reasons for early death after RT and to develop potential changes in indications and practice patterns, we analyzed patients at the Technical University of Munich (TUM) treated with RT between July 2018 and September 2019. Material and Methods All patients undergoing RT at the department of radiation oncology at our center are seen regularly for follow-ups after RT following a strict recall system. Therefore, clinical follow-up is available and documented prospectively in our electronic patient record system. Cut off for early death after RT was defined as death within 90 days after last RT. Patients with early death after RT treated between July 2018 and September 2019 were included in the analysis. Results We identified 32 patients from our database according to the defined inclusion criteria, of which 12 were female and 20 male. Median Karnofsky Index at the beginning of RT in these patients was 60% (range 20). 10 out of 32 patients were treated for bone metastases, 5 patients had a carcinomatous meningitis, 5 patients suffered from head and neck cancer and 3 patients were treated for brain metastases. 25 of all patients suffered from metastatic disease and 29 out of 32 patients were treated in palliative intention. 28 PO-1247 Analysis on early death in patients after radiotherapy: Should we change practice?

Seventeen patients (13 men, 4 woman) with a median age 67 years (42-81) were included (see Table 1). Pre- treatment median index pain severity was 7 (5-10). The median dose of tapentadol administered before RT was 100mg/24h (100-300mg). Four patients stopped tapentadol during the study (1 due to constipation GIII, 1 due to dizziness GII, 1 diarrhea GII, 1 unknown). Sixteen patients were assessable 1 month after RT and ten at 2 months. The overall RR 1 month after RT was 10/16=62.6%; 18.8% achieving a complete response (CR) and 43.8% a partial response (PR). The overall RR 2 months after RT was 5/10=50%; 10% achieving a CR and 40% a PR. In overall, for EORTC QLQ-c30, the median global health basal scores at baseline, 1 month and 2 months after RT were: 33.33, 50 (p=0.013) and 75 (p=0.011), respectively. Patients who responded to RT had significant improvement in EORTC QLQ-c30 emotional functioning (EF) (p=0.025) and fatigue symptom scale scores (p=0.035) one month after RT. There was also a statistically significant improvement (p=0.024) in painful site symptom QLQ-BM22 scores between baseline and 2 months after RT (Figure 1). Conclusion Palliative RT plus tapentadol shows remarkable pain response and QLF improvement especially regarding EF, fatigue and painful site symptom scales in patients with BM and moderate/severe NP. PO-1246 Stereotactic Body Radiotherapy For Bone Metastases In Oligometastatic-Oligoprogressive Patients F. Zerbetto 1 , C.L. Deantoni 1 , F. Borroni 1 , R. Tummineri 1 , A. Fodor 1 , M. Pasetti 1 , A. Chiara 1 , S. Broggi 2 , B. Longobardi 2 , L. Perna 2 , C. Fiorino 2 , N.G. Di Muzio 1,3 1 Ospedale San Raffaele IRCCS, Radiotherapy, Milan, Italy ; 2 Ospedale San Raffaele IRCCS, Medical Physics, Milan, Italy ; 3 Vita-Salute University, Medical and Surgery Department, MIlan, Italy Purpose or Objective The treatment of spine and bone metastases with standard external beam radiotherapy ensures a six months symptomatic and local control, which could be insufficient for long term survival oligometastatic patients (pts). Recent studies demonstrated long term pain and local control by dose intensification delivered with stereotactic body radiotherapy (SBRT). The aim of this study is to report clinical effectiveness and safety of SBRT using Cyberknife in spinal and bone metastases. Material and Methods From October 2017 to September 2019, 97 pts with 134 oligometastatic/oligoprogressive bone metastases were treated with Cyberknife in our Institution: 79% were spinal lesions, while 21% were non-spine. The most common primary sites were: prostate 61.9%, breast 12.7%, lung