Jane, I'm so glad the lesion is treatable with SBRT, and that you caught it early! My friend had a jump in CEA while having lung lesions (first days November 2012); a doctor she saw in the States (she's in Canada) told her to get her local doctors to perform a full body PET scan (hint hint)... nobody seemed worried, she never got her doctors to do that. First two weeks of December 2012, she had symptoms, during *two weeks*, before any doctor assessed her -they did it, when she ended up in the ER: the tumor was already bleeding and they performed an emergency craneotomy. It was successful during remarkable long time (one year before recurrence, just this past February!). She had even the chance to address, totally, the lung lesions in April 2013 (brain clear, lungs lesions responding to low dose Folfiri), and go for a protocol to *prevent* any recurrence, brain or anywhere. Sadly, that was a lost opportunity but my point is... it has not to be the same for you!
BTW, I attribute her long time before brain mets recurrence to luck, probably, but also to the fact that she took celecoxib (Celebrex, an anti arthritic medication) as radiosensitizer -to make the bad cells, only the bad ones, more receptive to radiation (edited to add: because she had IMRT -Intensity-modulated radiation therapy-, local, only to the place where the tumour was, after surgery). It has anticancer effects too. If you feel up to it, you can read about it
here; you have there articles you may want to show your doctors, so they may give you permission to take it (the rad onc gave my friend the ok for that, probably in the frame of 'it can't hurt...'-kind of thinking).
Also, the steroids (dexamethasone) are nasty. In short time, at high doses, they can provoke loss of muscle, diabetes, bone loss. You *have* to take dexamethasone, of course, but if you can help to get down inflammation for any other ways, the better. The Celebrex may help you with that and also boswellia.
Boswellia may look like a silly supplement (at any natural store) but is so potent that it's compared to dexamethasone ("could potentially be steroid-sparing for patients receiving brain irradiation"
Boswellia serrata acts on cerebral edema in patients irradiated for brain tumors: a prospective, randomized, placebo-controlled, double-blind pilot trial (2011). You can print that for your doctor.
I sincerely feel that this brain met episode won't keep you from doing that trip and enjoy more time : )