Reduction of breast density following tamoxifen treatment evaluated by 3-D MRI: preliminary study

This study analyzed the change in breast density in women receiving tamoxifen treatment using 3-D MRI. Sixteen women were studied. Each woman received breast MRI before and after tamoxifen. The breast and the fibroglandular tissue were segmented using a computer-assisted algorithm, based on T1-weighted images. The fibroglandular tissue volume (FV) and breast volume (BV) were measured and the ratio was calculated as the percent breast density (%BD). The changes in breast volume (Delta BV), fibroglandular tissue volume (Delta FV) and percent density (Delta%BD) between two MRI studies were analyzed and correlated with treatment duration and baseline breast density. The Delta FV showed a reduction in all 16 women. The Delta%BD showed a mean reduction of 5.8%. The reduction of FV was significantly correlated with baseline FV (P<.001) and treatment duration (P=.03). The percentage change in FV was correlated with duration (P=.049). The reduction in %BD was positively correlated with baseline %BD (P=.02). Women with higher baseline %BD showed more reduction of % BD. Three-dimensional MRI may be useful for the measurement of the small changes of Delta FV and Delta%BD after tamoxifen. These changes can potentially be used to correlate with the future reduction of cancer risk. (C) 2011 Elsevier Inc. All rights reserved.