ESTRO 2020 Abstract book

S518 ESTRO 2020

Graph 1). This improvement was seen in both PS 0-1 and PS 2 patient groups, with an improvement in median survival of 7.4 and 4.6 months respectively. Lethargy was the most common adverse effect, experienced by 74% of patients, followed by nausea in 33%. Confusion and memory impairment was seen in 8%. A general trend of increasing toxicity rates with increasing patient age and with hypofractionation was observed. Graph 1: Kaplan–Meier Curve Comparing Median Survival in patients with and without PCI

hypofractionated SRS(HSRS). Outcomes was measured in terms of local control(LC), toxicities, brain distant failure(BDF), and overall survival(OS). Prognostic factors influencing survival were assed too. Results The median follow-up time was 33months(range 3-183 months). Surgery plus SRS have been performed in 28(10.7%) cases, SRS in 141(53.8%), and HSRS in 93(35.5%). Seventy-seven(41.6%) patients received systemic therapy. The main total dose and fractionation used were 24Gy in single fraction or 24Gy in 3 daily fractions. Local recurrence occurred in 32(17.3%) patients. Median,6months,1-year-LC were 86 months(95%CI36-86), 87.2%±2.8, 77.8%±4.1. No severe neurological toxicity occurred. Median,6months,1-year-BDF were 23 months(95%CI9-44), 66.4%±3.9, 55.3%±4.5. Median,6months,1-year-OS were 7 months(95%CI 6-9), 52.7%±3.6, 33%±3.5. No severe neurological toxicity occurred. Stage at diagnosis, Karnofsky Performance Status (KPS), presence and number of extracranial metastases, and disease-specific-graded-prognostic- assessment (DS-GPA) score were observed as conditioning survival. Conclusion SRS/HSRS have proven to be an effective local treatment for BMCRC. A careful evaluation of prognostic factors as well as a multidisciplinary evaluation is a valid aid to manage the optimal therapeutic strategy for CTC patients with BMs. PO-0881 Visual outcomes in anterior visual pathway meningioma with standard vs hypofractionated FSR regimens PO-0882 Single centre review of the survival benefit and toxicity of PCI in Small Cell Lung Cancer S. Forner 1 , I. Vasiliadou 1 , J. Little 1 , M. Fenton 1 , S. Goyal 1 , R. Burcombe 1 , P. Brulinski 1 , T. Sevitt 1 1 Kent Oncology Centre, Clinical Oncology, Maidstone, United Kingdom Purpose or Objective Small cell lung cancer (SCLC) is associated with a poor prognosis; median survival is 7 months (1), and brain metastases are present in 50-60% of patients (2). Prophylactic Cranial Irradiation (PCI) is standard treatment for limited stage disease and considered for patients with extensive disease who are fit enough for treatment and have responded to chemotherapy. PCI has been shown to improve survival by 5.4% at 3 years (2). We reviewed the use of PCI at KOC to assess survival and morbidity data. Material and Methods A retrospective analysis of all patients treated for small cell lung cancer at the Kent Oncology Centre between 2004 and 2008 was performed. Toxicity data was gathered from clinical assessments during and following treatment. Survival data was collected from electronic records and GP databases. Data was analysed and statistical analyses performed using SPSS software. Results Of 107 patients identified, 24 had limited stage and 83 had extensive stage disease. Median survival for the total population was 10.3 months (12.8 months for limited stage disease and 9.4 months for extensive stage disease). Performance status (PS) significantly affected prognosis: median survival was 1 month for patients who were PS 3, compared with 12.8 months for patients PS 0-1 (p=0.003). Subgroup analysis revealed an additional 3.2 months median survival benefit for patients treated with consolidation thoracic irradiation. Excluding the patients with brain metastases at diagnosis, the addition of PCI significantly improved median overall survival from 6.3 months to 15 months (p=0.001) (see Abstract withdrawn

Conclusion In this cohort, PCI confers a substantial improvement in median survival in small cell lung cancer, with acceptable associated toxicity. Improvement is seen across both PS 0- 1 and PS 2 patient groups. The analysis supports the use of PCI for these patients; the additional survival benefit is both statistically and clinically significant given the poor prognosis of SCLC. As new treatment combinations emerge, the use of PCI for patients receiving combination chemotherapy and immunotherapy will require prospective evaluation. PO-0883 Early outcomes in patients with skull base chordomas and chondrosarcomas treated with proton therapy A. Turkaj 1 , I. Giacomelli 1 , M. Cianchetti 1 , D. Scartoni 1 , D. Amelio 1 , S. Vennarini 1 , B. Rombi 1 , F. Dionisi 1 , M. Amichetti 1 1 Centro di Protonterapia, Azienda Provinciale per i Servizi Sanitari Trento, Trento, Italy Purpose or Objective Skull base chordomas (C) and chondrosarcomas (CS) are rare, locally aggressive tumors located adjacent to critical structures. Surgery is recognized as the gold standard approach,however gross total resection is rarely possible for this reason most patients undergo subtotal resection or biopsy followed by radiotherapy.The aim of our retrospective study is to evaluate the toxicity profile and clinical outcome of patients (pts) with skull base chordomas and chondrosarcomas treated at Trento Proton Therapy. Material and Methods Between June 2015 and September 2019,36 patients with skull base C and CS were irradiated with proton therapy (PT) at our institution.Mean age was 51 years (range:10- 83).There were 32 C (89%),and 4 CS (11%).Tumors were located in clivus n= 36,right petroclival region n=1 and sellar region n=1.Median diameter at the time of treatment was 15,93 mm (range 0-51).Two lesions were only biopsied and treated with exclusive PT.Thirty four lesions had been treated with≥1 surgery;27 cases had gross residual disease at the beginning of PT;in those cases PT was performed with radical intent,8 cases were treated with adjuvant intent.Four cases were re-irradiation,3 of