Cerebral metastases: do size, peritumoral edema, or multiplicity predict infiltration into brain parenchyma?

Background Brain metastases (BMs) are the most frequent malignancy of the central nervous system. Previous research suggested that some metastases show infiltrative behavior rather than sharp demarcation. We hypothesized that three magnetic resonance (MR) imaging parameters—(a) tumor size, (b) extent of peritumoral edema, and (c) presence of multiple BMs—are predictors of cellular invasion beyond the surgically identifiable tumor margins.