TOMOGRAPHY, March 2017, Volume 3, Issue 1: 16-22
Quantitative Analysis of the Spatial Distribution of Metastatic Brain Lesions
1Department of Radiation Oncology and 2Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
Brain metastases (BMs) are the most common intracranial malignancy and afflict ~10%–20% of patients with cancer. BMs tend to present at the boundaries of gray and white matter because of the distribution of small vessels. In addition, metastases may not be randomly distributed across gross anatomical regions of the brain, but this has not previously been quantified. We retrospectively analyzed a series of 28 patients with recurrent BMs with a total of 150 lesions. Each lesion was manually defined based on T1 gadolinium-enhanced imaging. Standard brain atlases were used to identify the anatomical brain region affected by each BM and the frequency of metastases in each region was compared with the expected probability, which was assumed to be a random distribution based on the brain volume. After correction for multiple comparisons, the paracingulate gyrus was found to have a statistically significant increase (P = 4.731 x 10-9) in the rate of BMs relative to the random spatial distribution. A nonstochastic spatial distribution of metastases may be used to guide partial brain radiotherapy with risk-adapted dose delivery and reduce the risk of neurotoxicity due to overtreatment.
Video 1: Video: Three-dimensional rendering of the 150 BMs detected in this cohort. The centroid of each BM was identified and then dilated to the mean diameter for all lesions. This assumes symmetric growth in all directions from a single metastatic focus for each of the lesions and is an aid to qualitatively visualize the spatial distribution of all lesions included in the analysis.
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