ESTRO 2020 Abstract book

S588 ESTRO 2020

Survival outcomes were calculated using SPSS statistics software. Results 20 patients have been identified and included in the study. All patients presented with two synchronously diagnosed lung cancer and received SABR for both lesions. Patient and tumour demographics are summarised in table 1. Distribution of lung cancers is presented in picture 1. 65% of lesions were treated with 55 Gray in 5 fractions, 28% with 60 Gray in 8 fractions, 7% with 54 Gray in 3 fractions. 90% of patients received both SABR treatments within one month of each other. One grade 2 pneumonitis occurred after treatment. No oesophagitis occurred. Median overall survival was 718 days. Median progression free survival was 565 days. Overall local control was 87.5%. Picture 1

Material and Methods All patients who received SABR at a large cancer centre in the UK from 01/01/2010 to 31/12/2016 were reviewed. Patients were included if they had pre-SABR full pulmonary function tests (PFTS) which include forced expiratory volume in one second (FEV1), FEV1 as a percentage of predicted (%FEV1), forced vital capacity (FVC) and DLCO as a percentage of predicted (%DLCO). Patient and tumour demographics were obtained for each patient from electronic health records. Survival times were calculated and analysed using SPSS statistics. Results 410 patients with complete medical records and pre-SABR PFTs were included in the study. Median follow up was 26.1 months. Patient and cancer demographics are summarised in table 1. Median overall survival for the whole cohort was 29.7 months. %DLCO was found to be associated with worse overall survival (cox regression, p=0.001). Performance status and age were also found to be associated with worse survival (p=0.035 and p<0.001 respectively). Overall survival of patients with %DLCO>50% of was 31.9 month, versus 25 months (log rank p=0.011) for patients with %DLCO <50%.

Table 1 Median Age

76 years

Sex

Male 195 (48%) Female 215 (52%)

Performance Status

0 1 2 3

17 (4%)

160 (39%) 195 (48%)

38 ( 9%)

Table 1

Charlson Comorbidity Score (median)

6

Cancer stage

1a 1b 2a 2b

297 (72%) 99 (24%)

1 (0%) 13 (4%)

Graph 1

Conclusion SABR to synchronously diagnosed early lung cancer is well tolerated. Local control and survival outcomes are comparable with existing literature. PO-1017 Poor Diffusing Capacity for Carbon Monoxide (DLCO) is associated with worse survival post SABR F. Sun 1 , P. Jain 1 , P. Murray 1 , K. Clarke 1 , P. Dickinson 1 , M. Teo 1 , A. Saha 1 , K. Franks 1 1 Leeds cancer centre, Oncology, Leeds, United Kingdom Purpose or Objective Stereotactic ablative radiotherapy (SABR) is the standard non-surgical management for peripheral early lung cancers. Existing literature suggest SABR is safe in patients with poor lung function. This study evaluates the effect of lung function on survival outcomes for patients treated with SABR.

Conclusion Poor %DLCO was found to be associated with poor overall survival in this study. Further studies using radiation dosimetry and additional co-morbidity factors are needed to clarify true correlation and post SABR survival. PO-1018 Lung SABRT treatment in oligometastatic patients, a prospective review E. Csiki 1 , M. Simon 1,2 , J. Papp 1,2 , Á. Kovács 1,2 1 University of Debrecen, Clinic of Oncoradiology, Debrecen, Hungary ; 2 University of Pécs, Faculty of