Authors: ChengChia Lee Max Wintermark Zhiyuan Xu ChunPo Yen David Schlesinger Jason P Sheehan
Publish Date: 2014/04/24
Volume: 118, Issue: 2, Pages: 351-361
Abstract
To evaluate the effect of stereotactic radiosurgery SRS on intracranial metastases with diffusionweighted imaging/apparent diffusion coefficient maps A total of 107 patients with 144 metastases larger than 1 cm in diameter were retrospectively reviewed We calculated the DWITumor/white matter ratios DWIT/WM ratio between the metastases and the normal contralateral frontal white matter at each time point We also recorded the ADC values for metastases ADCT values The DWIT/WM ratio and ADCT values were assessed for correlation with the patients’ tumor response brain edema and survival A decrease in DWIT/WM ratios was seen in the controlled metastases and an increase in the DWIT/WM ratio were seen in the metastases with poor tumor control On the other hand an increase in ADCT values was seen in the controlled metastases and a decrease in ADCT values was seen in the metastases with poor control The differences were significant p value 0001 and 0002 respectively Sensitivity of a decrease in the DWIT/WM ratio to make an early prediction of tumor control was 839 and specificity was 885 When using the initial ADCT values of metastases to predict tumor response sensitivity and specificity were 855 and 727 respectively DWI/ADC is a practical method for studying the efficacy of SRS and predicting early metastases response progression A decrease signal on DWI and increased ADC values are indicators of good tumor control and reflect the beneficial effect of SRS
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