ESTRO 2024 - Abstract Book

S779

Clinical - CNS

ESTRO 2024

Results:

50% of patients underwent at least one additional irradiation, 61% of which occurred within a year. The number of treatment courses ranged from 2 to 7 (mean 2.6), and the intervals between treatment courses ranged from 2 to 81 months (mean 10.3 months), with the time span between the first and last treatment ranging from 2 to 88 months (mean 16.7 months) (Fig. 1). For patients requiring re-irradiation, 391 treatment courses were conducted, comprising 534 plans - 71% of them stereotactic - and addressing 841 targets (max. 23 per plan). A Kaplan-Meier survival analysis was performed for patients with a follow-up period exceeding two years, as depicted in Fig. 2.

Fig. 1: Treatment patterns in repeated courses of radiotherapy for new brain metastases: (a) Distribution of time intervals (in months) between treatment series: blue bars represent the entire duration of treatments, while green bars indicate the time span between subsequent courses. (b) Number of multiple treatment courses per patient.

Fig. 2: Kaplan-Meier survival curves for two cohorts: 'multiple STX' (received multiple stereotaxic treatments) and 'one STX' (received a single stereotaxic treatment). The 95% confidence interval is shown. Patients with prior whole brain radiation were excluded.