ESTRO 2023 - Abstract Book

S721

Monday 15 May 2023

ESTRO 2023

differences in the trend of these parameters were assessed using the non-parametric Wilcoxon rank-sum test by grouping patients according to ADT administration (arm B vs A, yes vs no) and site of metastases (bone versus lymph node). Results The current analysis comprised 82 patients (41 arm A SBRT only, 40 arm B, SBRT+ADT). When patients were stratified by ADT administration (Fig1), cholesterol values showed an increasing trend in the group receiving ADT (p < .001), and the change in albumin level was also different between the two groups (p < .05). When patients were stratified by site of metastases (52 lymph nodal, 29 bone localizations) (Fig2), the values of NLR and NLRAR were found to be increased in patients with bone localizations (p < .05).

Conclusion The addition of ADT appears to have an impact on changes in cholesterol and albumin, two markers of a deteriorating quality of life. Additionally, it appears that the site of metastases and inflammatory status are associated. As bone localizations are linked to a lower response rate than lymph node-only sites, this outcome is consistent with the well-known fact that a higher inflammatory status results in a worse prognosis. The examined parameters seem to represent intriguing candidates for possible use in clinical decision-making to group patients according to whether they would benefit more from less aggressive therapies. The validation of these potential biomarkers requires further evaluations, correlations with clinical outcomes and extended follow-up data. MO-0875 Sarcopenia - a prognostic biomarker for definitive chemoradiotherapy in oesophageal cancer patients D. McSweeney 1 , S. Raby 2 , J. Weaver 2 , G. Radhakrishna 2 , A. Green 3 , P.A. Bromiley 4 , M. van Herk 1 , A. McWilliam 1 1 University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom; 2 The Christie Hospital NHS Foundation Trust, Medical oncology, Manchester, United Kingdom; 3 EMBL European Bioinformatics Institute, Protein Sequence Resources, Cambridge, United Kingdom; 4 University of Manchester, Division of Informatics, Imaging and Data Sciences, Manchester, United Kingdom Purpose or Objective Sarcopenia is an emerging biomarker of patient frailty that is associated with increased toxicity and decreased survival in a number of cancer types. Definitive chemoradiotherapy (dCRT) is the standard of care for patients with unresectable oesophageal cancer (OC). But research on the role of sarcopenia in this population is lacking. Sarcopenia is usually assessed by segmenting skeletal muscle (SM) at the L3 vertebral level. For OC patients treated with radiotherapy (RT), planning scans do not always include L3. The ability to assess SM at other vertebral levels would also enable longitudinal studies of body composition. We therefore investigate the prognostic value of SM area, assessed at T12, in non-metastatic OC patients treated with dCRT. Materials and Methods RT planning CTs were collected for 140 patients treated with dCRT (50 Gy in 25 fractions; carbo-taxol or cis-cap) between 01/01/2017 and 01/10/2020. T12 was manually identified and SM was automatically segmented by an in-house deep learning model. Failed segmentations were manually corrected. SM index (SMI) was defined as single slice muscle area after thresholding between -29 HU and 150 HU (to account for intra-muscular fat) normalised by patient height squared.