ESTRO 2023 - Abstract Book

S379

Sunday 14 May 2023

ESTRO 2023

Results A scatter plot of % loss of bone marrow vs % change in lymphocyte counts at weeks 2 and 4 was produced (lower figure). The % loss of FLT uptake in bone marrow and reductions in lymphocyte counts were positively correlated from baseline to both weeks 2 and 4. The correlation from baseline to week 4 was highly significant (p<0.003). The correlation from baseline to week 2 was comparatively weaker, suggesting that time is required for radiation damage to be fully expressed. Conclusion There was a strong correlation between the estimated percentage of proliferating bone marrow ablated by radiation and percentage worsening of lymphocyte nadirs from baseline to week 4. Relationships between percent marrow ablation and lymphocyte counts were non-linear suggesting that other factors may contribute.

MO-0474 Is comorbidity associated with interruption of RT treatment in patients with lung cancer? G. Motamedi-ghahfarokhi 1 , C. Faivre-Finn 1 , M. Van Herk 1 , H. Mistry 2 , G. Price 3 , A. Abravan 3 1 University of Manchester/The Christie NHS Foundation Trust, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health and Department of Radiotherapy Related Research, Manchester, United Kingdom; 2 University of Manchester, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Manchester, United Kingdom; 3 The University of Manchester/ The Christie NHS Foundation Trust, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health and Department of Radiotherapy Related Research, Manchester, United Kingdom Purpose or Objective Radiotherapy (RT) plays an important role in the management of patients with lung cancer. Many patients present with comorbidities, and the degree to which comorbidity burden affects outcomes after treatment is not fully understood. An important factor influencing outcomes is the timely completion of treatment. This study presents comorbidity prevalence in a cohort of patients with non-small cell lung cancer (NSCLC) and investigates if baseline comorbidities are associated with treatment interruption. Materials and Methods Data from 1,656 stage I-III NSCLC patients treated with curative-intent RT (55 Gy in 20 fractions, +/- sequential chemotherapy) between January 2013 and June 2022 with available Adult Co-Morbidity Evaluation (ACE-27) from a single