This is not about brain mets but about radiation-induced changes in primary brain cancer and notes that arteriol venous malformations (slightly different blood vessels than normal) seems to increase the risk of this developing post SRS. Since I am having adjacent swelling in my cerebellum with no symptoms we are doing watchful waiting for a few weeks as its either atypical swelling or atypical leptomeningeal disease -- nice options, eh?
"Radiation effects have generally been divided into acute, subacute, and chronic phases [16]. The acute phase is first 2 months following irradiation, the subacute occurs from 2 to 6 months, and the chronic is after 6 months."
"20 Gy or more for the targeted lesion. One possible explanation is that hemodynamic changes result from changes to AVM vessels [9]. Two patients with AVM in the present study exhibited new lesions when shrinkage of AVMs was seen following STI. Generally, complete obliteration of cerebral AVM can occur from 4 months to 5 years after SRS"
Radiation-induced changes in the brain following stereotactic irradiation evaluated by sequential MRI (2004)
http://www.sciencedirect.com/science...72349604000198