ESTRO 2021 Abstract Book

S1057

ESTRO 2021

multivariate analysis, patient age, FIGO stage, lymph node metastasis, serum albumin level, and treatment response emerged as significant independent predictors of both OS and PFS. Patients with FIGO stage > IIB, large tumors (> 4 cm), lymph node metastasis, and no CR after definitive CRT had significantly lower serum albumin levels, higher serum globulin levels, and higher AGRs compared to patients with FIGO stage ≤IIB, tumors ≤ 4 cm, no lymph node metastasis, and a CR. Conclusion Albumin and globulin levels, and AGR were correlated significantly with tumor size, stage, lymph node metastasis, and treatment response. However, AGR and AGS were not found to be significant predictive factor for survival. Serum albumin level is thus a suitable biomarker for serving to predict patient outcomes. PO-1282 Single Institution Outcomes for CT Guided Brachytherapy for Cervical Cancer M.T. Elahi 1 , J. Morgan 1 , A. Stillie 1 , M. Zahra 1 1 Western General Hospital, NHS Lothian, Edinburgh Cancer Centre, Edinburgh, United Kingdom Purpose or Objective To review the overall survival (OS) and disease-free survival (DFS) outcomes for the cohort of patients with cervical cancer treated radically at our centre between 2011 and 2018. Materials and Methods The staging, treatment details and outcome data were retrospectively reviewed for all patients treated radically for cervical cancer with brachytherapy for the period between 2011 to 2018. All patients had an EBRT dose of 45Gy in 25 fractions to all the pelvis ± para-aortic area with concurrent cisplatin. They all had an MRI scan in the last week of EBRT to help plan the brachytherapy implant. A ring and tandem was used to deliver the brachytherapy in 3 fractions over 1 week, which were individually CT planned aiming for a combined total dose EQD2 D90 to the HRCTV of over 85Gy with individualised modifications based on dose to organs at risk and tumour asymmetry. The OS and DFS were calculated for the entire cohort and also for subgroups based on stage and on the total D90 (group 1 <80Gy, group 2 80-85Gy, and group 3 >85Gy). The Kaplan-Meier method was used with log rank value to assess for statistical significance, with two-tailed significance testing and with a p-value <0.05 deemed significant. All analysis was done using IBM SPSS statistical software version 24. Results A total of 156 patient case notes were reviewed for the 8 year period. The median age was 44 years (min 21 years to max 84 years). The stage (FIGO 2009) distribution was: stage I (N=13), stage II (N=125), stage III (N=12) and stage IVA (N=6). The median dose combined D90 to the HRCTV to the whole cohort was 84.9Gy (min 54.3 to max 92.6). Five-year DFS and OS for the whole cohort was 72% and 74% respectively. When analysed by stage the 5 year DFS for stage I was 84.6%, stage II was 76.8%, stage III was 33.3% and stage IVA 33.3%. The 5 year OS was 76.9% in stage I, 79.2% in stage II, 41.7% in stage III and 33.3% in stage IV. For the groups based on total D90 the 5 year DFS for group 1 was 31.3%, group 2 69.2% and group 3 84%. Whilst the 5 year OS rate in group 3, group 2 and group 1 was 81.3%, 73.8% and 43.8% respectively.