The STEREOBRAIN trial: a case-control study of SRS vs WBRT in 4-10 brain metastases
Maximilian Niyazi,
Germany
PO-1127
Abstract
The STEREOBRAIN trial: a case-control study of SRS vs WBRT in 4-10 brain metastases
Authors: Raphael Bodensohn1, Anna-Lena Kaempfel2, Anne-Laure Boulesteix3, Robert Forbrig4, Sylvia Garny1, Stefanie Corradini1, Claus Belka1, Maximilian Niyazi1
1University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany; 2University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany; 3University of Munich, Institute for Medical Information Processing, Biometry and Epidemiology, Munich, Germany; 4University Hospital, LMU Munich, Institute of Neuroradiology, Munich, Germany
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Purpose or Objective
At
our department, whole brain radiotherapy (WBRT) has been the treatment of
choice in 4-10 brain metastases until 2017. This paradigm was entirely changed
to include patients within the STEREOBRAIN trial (ID: DRKS00014694). We
designed this prospective single arm trial to systematically introduce
stereotactic radiosurgery (SRS) to 4 to 10 brain metastases comparing this new
treatment regimen with the former approach. We aimed at showing a survival
benefit of this novel treatment paradigm.
Material and Methods
Inclusion criteria were 4-10 brain
metastases, largest diameter 2.5 cm, all histologies except SCLC, germ cell
tumors, lymphoma, and ECOG ≤ 2. The retrospective WBRT cohort was identically
selected from consecutive patients from 2012 to 2017 in a 1:2 fashion. At a
significance level of 5%, a total number of 99 events (deaths) across the two
groups allows to detect an increase in median OS from 6 months (retrospective
WBRT cohort) to 11 months (SRS) considered clinically relevant (and corresponding
to a hazard ratio of 0.55 assuming exponential distributions of survival times
within groups) with a power of 80%. Propensity-score
matching is planned to take confounders into account given the inherent bias
caused by different treatment periods. Secondary endpoints were intracranial
PFS and toxicity. Multiple brain mets SRS was performed using a
single-isocenter technique.
Results
Patients were recruited from 2017 – 2020 and end of F/U was July 1st
2021. Forty patients were recruited to the SRS cohort and 70 patients were
eligible within the WBRT cohort (81 events altogether).
Conclusion
Respective results from the full analysis dataset will be presented and discussed at
the ESTRO 2022.