Based on the low inter-individual topographic variability of the Circle of Willis found in this study, reliable retrospective estimations of radiotherapy doses can be delivered to these arterial structures.
Why this matters
Research shows a significant increase in morbidity and mortality due to long-term iatrogenic effects of radiotherapy on arterial structures, especially in children with brain tumors.
Although recent studies have found an increased risk of stroke due to the radiation-related toxicity, no recommendations currently exist for the contouring and dose limitations for Circle of Willis irradiation.
Establishing a dose-response relationship depends on accurate and reproducible retrospective dosimetric estimations/dose reconstruction in large cohorts of patients who have received radiotherapy in the past.