Propensity for different vascular distributions and cerebral edema of intraparenchymal brain metastases from different primary cancers.

PURPOSE: This study seeks to ascertain whether different primary tumor types have a propensity for brain metastases (BMs) in different cerebral vascular territories and cerebral edema.
METHODS: Consecutive adult patients who underwent surgical resection of a BM at a tertiary care institution between 2001 and 2011 were retrospectively reviewed. Only patients with the most common primary cancers (lung, breast, skin-melanoma, colon, and kidney) were included. Preoperative MRIs were reviewed to classify all tumors by cerebral vascular territory (anterior cerebral artery-ACA, lenticulostriate, middle cerebral artery-MCA, posterior cerebral artery-PCA, posterior fossa, and watershed), and T2-weighted FLAIR widths were measured. Chi square analyses were performed to determine differences in cerebral vascular distribution by primary tumor type, and one-way ANOVA analyses were performed to determine FLAIR signal differences.
RESULTS: 669 tumors from 388 patients were classified from lung (n = 316 BMs), breast (n = 144), melanoma (n = 119), renal (n = 47), and colon (n = 43). BMs from breast cancer were less likely to be located in PCA territory (n = 18 [13%]; χ2 = 6.10, p = 0.01). BMs from melanoma were less likely to be located in cerebellar territory (n = 11 [9%]; χ2 = 14.1, p < 0.001), and more likely to be located in lateral (n = 5 [4%]; χ2 = 4.56, p = 0.03) and medial lenticulostriate territories (n = 2 [2%]; χ2 = 6.93, p = 0.009). BMs from breast and melanoma had shorter T2-FLAIR widths, with an average [IQR] of 47.2 [19.6-69.2] mm (p = 0.01) and 41.2 [14.4-62.7] mm (p = 0.002) respectively. Conversely, BMs from renal cancer had longer T2-FLAIR widths (64.2 [43.6-80.8] mm, p = 0.002).
CONCLUSIONS: These findings suggest that different primary tumor types could have propensities for different cerebral vascular territories and cerebral edema.