ESTRO 2023 - Abstract Book

S380

Sunday 14 May 2023

ESTRO 2023

institute were collected. RT was given to patients on weekdays over four weeks. Overall treatment duration (days) was defined as the number of weekdays from treatment initiation to last fraction received. Comorbidities were collected at diagnosis using ACE-27 values and were considered as a binary variables (with/without comorbidity). Total comorbidity burden was categorised as none, one, two, and more than two comorbidities. The association of each comorbidity and the total number of comorbidities with overall treatment duration was assessed via multivariable linear regression. Results 1,491 patients completed treatment within 20 days, 157 took more than 20 days and 8 patients never completed the treatment due to death that were excluded from analysis (Figure 1). Cardiovascular (32%), respiratory (29%) and endocrine (8%) conditions were the most common comorbidities (Table 1). After adjusting for age, sex, T stage, N stage, performance status, gross tumour volume (GTV), only obesity (1%) was found to be associated with an increase in treatment duration by an average of 1 day (p = 0.011). Regarding the total number of comorbidities, overall treatment duration for patients with one (p = 0.017), two (p = 0.003), and more than two (p = 0.022) comorbidities increased by an average of 0.2, 0.3, and 0.2 days respectively (but not by a clinically relevant amount) than those that had no comorbidities.