Would you do SRS for a patient who cannot receive gadolinium contrast and has a single brain metastasis on non-contrast MRI?  

There is a reasonable concern that other small brain metastasis could  be present without obtaining fine cut T1 imaging with gadolinium contrast. As long as the patient is otherwise a reasonable candidate for radiosurgery, and can return for follow up, I would feel comfortable going ahead with ...

While the concern for smaller metastases going undetected remains, from a brain preservation point of view, we use GRE sequences and other means to detect what mets we can use SRS to. Regular follow up is key. Smaller mets are clinically inconsequential except in the setting of leptomeningeal diseas...