Trial Information

Hypofractionated Stereotactic Radiotherapy (HF-SRT) for Large-Volume Brain Metastases

With increasing volume of tumor, the dose of radiosurgery that can be safely delivered to
recurrent oligo-metastases in the brain must be reduced. However, reducing the dose of
radiosurgery also compromises local control. There is mounting evidence of a local control
benefit to a hypofractionated approach in radiation delivery for brain metastases compared
with single fraction radiosurgery. Here we propose a novel therapeutic strategy that builds
on this concept whereby time between each delivered fraction will enable us to measure and
adapt to response, with the objective of reducing irradiated volumes and improving outcomes.
In general, the treatment of malignant tumors benefits from fractionation of the dose due to
a number of radiobiological properties (redistribution, reoxygenation, repair) that
distinguish, and select against, malignant lesions in the fractionation process.
Hypofractionated stereotactic radiotherapy (HSRT) is a method of delivering a highly
conformal dose distribution in a few treatment sessions using a relocatable stereotactic
frame. HSRT may be an attractive alternative to SRS because it may 1) improve patient
comfort by removing the invasive nature of SRS frames, 2) confer a radiobiologic advantage
over single fraction treatment.