ESTRO 2021 Abstract Book

S1161

ESTRO 2021

PO-1413 Melanoma brain metastasis: The outcome of WBRT in the era of effective systemic therapy C. Waldstein 1,2 , W. Wang 2,4 , W. Wang 3 , S. Lo 3 , B. Shivalingam 3,5 , G.B. Fogarty 6,7 , M.S. Carlino 3,4,8 , A.M. Menzies 3,4,9 , G.V. Long 3,4,9 , A. Hong 3,4,7 1 Medical university vienna, Radiation oncology, Vienna, Austria; 2 Westmead Hospital, Department of Radiation Oncology, Sydney, Australia; 3 The University of Sydney, Melanoma Institute Australia, Sydney, Australia; 4 The University of Sydney, Sydney Medical School, Sydney, Australia; 5 Royal Prince Alfred Hospital, Department of Neurosurgery, Sydney, Australia; 6 Melanoma Institute Australia, The University of Sydney, Sydney, Australia; 7 Mater Hospital, Genesiscare, Radiation Oncology, Sydney, Australia; 8 Crown Princess Mary Cancer Centre, Department of Medical Oncology, Sydney, Australia; 9 Royal North Shore Hospital, Department of Medical Oncology, Sydney, Australia Purpose or Objective Whole brain radiation therapy (WBRT) is sometimes recommended for patients with multiple melanoma brain metastasis (MBM) in addition to systemic therapy and/or local therapy. We report outcomes of WBRT and identify associated factors in the era of modern systemic therapy. Materials and Methods Ninety patients treated with WBRT between 2011 and 2018 were included. Records were analyzed for clinical and treatment characteristics, radiation techniques, systemic therapy and outcomes. Overall survival (OS) rates were calculated using the Kaplan-Meier method; factors affecting OS were assessed using the log-rank test as well as Cox regression. Results The median age was 63 years and the median follow-up was 4.5 months. The median OS from diagnosis of MBM was 8 months (range, 1-83 months), median OS from the beginning of WBRT was 5 months (range, 0-64 months). Patients with BRAF mutation who had prior systemic treatment (n=31) had a median OS from WBRT of 4.6 months versus 5.2 months for those with BRAF wild type disease (n=27). Patients with no systemic treatment prior to WBRT (n=32) had a median survival of 6.7 months (p=0.65). In multivariable analysis, the presence of neurological symptoms was associated with worse OS (p=0.029) and prior surgery with better OS PO-1414 Neoadjuvant or Adjuvant radiotherapy in advanced soft tissue sarcomas: a level playing field? O. Muñoz Muñoz 1 , A.M. Burgueño Caballero 2 , J. Peinado Serrano 2 , I. Rincon Perez 1 1 hospital Universitario Virgen Del Rocio, Oncology Radiotherapy, Sevilla, Spain; 2 hospital Universitario Virgen Del Rocio , Oncology Radiotherapy, Sevilla, Spain Purpose or Objective Radiotherapy (RT) and conservative surgery (CS) is a well-established soft tissue sarcomas (STS). The integration of chemotherapy (CH) to standard neoadjuvant radiotherapy (N-RT) remains controversial even for these patients (pts) due to conflicting results from different trials compared to adjuvant radiotherapy (A-RT). This retrospective study evaluated the oncological outcomes of N-RT and A-RT, CS outcomes and tolerability in this setting of patients with CTS treated at our center. Materials and Methods A retrospective analysis of a cohort of consecutive pts was performed. Patient selection included with STS treated with N-RT (50Gy in 25fractions)+CH or A-RT (60Gy in 30fractions) +/-CH after CS. Analysis was performed using Pearson's X2 test and Fisher's exact test to compare and analyse the effect of N-RT versus A- RT, CS outcome and toxicities; p-value <0.05 was considered statistically significant. Overall survival (OS), progression-free survival (PFS), local-regional failure-free survival (LR-FFS) and distant metastasis-free survival (DMFS) were generated using the Kaplan-Meier method (SPSS v .25). Toxicity was scored using the CTCAE v.4.03 and recorded weekly during RT and monthly after completion of RT. Results Between January/2016 and January/2021, 136 pts (M/F 79/57) with STS were treated at our centre. The median age of 55 y (16-92). Tumor grading were 5% Grade I, 34% GII and 61% GIII. In term of histology, undifferentiated pleomorphic sarcoma together with myxofibrosarcoma were the most frequent 20.5% in both cases, followed by myxoid liposarcoma 17.6% and leiomyosarcoma 13.2%. 48,6% were treated with N-RT+CH and 40% with A-RT+CH and 11,4% A-RT alone. The techniques were used 3D-CRT 32%, IMRT-IGRT 59% and VMAT 9%. The mean dose was 60Gy (30-66Gy) and mean treatment time 42 days. 5 pts did not complete RT treatment (2 disease progression during treatment and 3 Toxicity > Grade 3). At 36 months, with a median follow-up of 31,4 months (3,4–72,3) in N-RT arm and A-RT arm respectively, 3-year OS rates was 87% vs 74% (p 0.127); 3-year PFS rates was 69 % vs 57% (p 0.260); 3-year LR-FFS rates was 96 % vs 82% (p 0.021); 3-year DMFS rates was 72 % vs 61% (p 0.342). For CS outcomes, in N-RT arm and A-RT arm respectively, R0: 62 Vs 35 (45,6% Vs 25,7%); R1: 4 Vs 35 (3% Vs 25,7%) with Pearson's X2 test and Fisher's exact test (p < 0,000) statistically significant differences; For toxicities outcomes, in N-RT arm and A-RT arm respectively, Toxicity grade3 22 Vs 31 (16% Vs 23%) with Pearson's X2 test and Fisher's exact test (p < 0,220) no statistically significant differences were found; Conclusion Our data suggest similar results in terms of overall disease control for N-RT and A-RT, but show a higher rate (p=0.002). Conclusion In selected patients with MBM treated with systemic therapy with known intracranial activity, WBRT was used in addition to surgery and SRS. Future studies should further determine the role of systemic treatment in combination with radiotherapy in MBM patients, particularly in patients with multiple brain metastases. Digital Poster: Sarcoma