Investigating the Role of Delayed Contrast Magnetic Resonance Imaging (MRI) to Differentiate Radiation Necrosis from Tumour Recurrence in Brain Metastases after Stereotactic Radiosurgery.

The incidence of radionecrosis (RN) after stereotactic radiosurgery (SRS) to brain metastases is increasing. An overlap in the conventional MRI appearances of RN and tumour recurrence (TR) is diagnostically challenging. Delayed contrast MRI compares contrast enhancement over two time periods to create treatment response assessment maps (TRAMs). We aim to assess the utility of TRAMs in brain metastases patients.