ESTRO 2022 - Abstract Book

S326

Abstract book

ESTRO 2022

Conclusion This study did not find that 4DCT artifacts from breathing irregularity are associated with poorer survival. Both longer scan times and longer breathing periods were associated with survival, possibly because patients with smaller tumours and better performance status tend to breathe slower. This finding is opposite to Sentker, where longer periods caused under-sampling artifacts, possibly because of differences in scan protocol. In multivariable analysis the effect disappeared except for a negative effect of long scan times that may be related to missing information when a full scan cannot be completed. Manufacturers should fix this.

MO-0390 CCI and TNM stage do not influence early mortality risk after definitive radiotherapy in NSCLC

K.H. Jensen 1 , J. Friborg 1 , I.R. Vogelius 1 , M. Pøhl 1 , M.S. Frank 2 , O. Hansen 3 , T. Schytte 3 , C. Kristiansen 4 , M. Knap 5 , M. Skovborg 6 , T. McCulloch 6 , G. Persson 7 1 Rigshospitalet, Department of Oncology, Copenhagen, Denmark; 2 Zealand University Hospital, Næstved , Department of Oncology, Næstved, Denmark; 3 Odense University Hospital, Department of Oncology, Odense, Denmark; 4 Vejle Hospital, Department of Oncology, Vejle, Denmark; 5 Aarhus University Hospital, Department of Experimental Clinical Oncology, Aarhus, Denmark; 6 Aalborg University Hospital, Department of Oncology, Aalborg, Denmark; 7 Herlev Hospital, Department of Oncology, Herlev, Denmark Purpose or Objective In patients with locally advanced non-small-cell lung cancer (NSCLC), definitive radiotherapy (RT) or chemoradiotherapy (CRT) is associated with considerable toxicity and approximately half of patients die within two years. A better understanding of early mortality is needed to improve patient selection and guide supportive interventions. In this population-based study, we investigated the impact of the Charlson Comorbidity Index (CCI), TNM stage and performance status on early mortality risk. We also hypothesized that there would be a high-risk interval for early mortality, and therefore assessed the temporal distribution of early deaths. Materials and Methods Patients with stages IIa, IIb, IIIa and IIIb NSCLC (according to the 7th edition of the AJCC/UICC TNM Classification) treated with RT/CRT in Denmark 2010–2017 were included. Patients were identified in local, electronic radiotherapy charts and additional data were obtained from the Danish Lung Cancer Registry. Patients were excluded if the treatment was pre- or postoperative or if they received stereotactic body radiation therapy. Early mortality was defined as death within 180 days from RT/CRT initiation. Possible risk factors, including age, sex, performance status, TNM stage, the CCI, histology and treatment period, were investigated using multiple logistic regression. Results We included 1742 patients and early mortality occurred in 10%. In multivariable analysis, age, sex, performance status and tumor histology were significantly associated with the risk of early mortality, while the CCI, TNM stage and treatment period were not (Table 1). Only a small proportion of deaths occurred during the first two months, but otherwise there was an even temporal distribution of deaths across the first year following RT/CRT (Figure 1). Despite similar early mortality