Application of diffusion-weighted magnetic resonance imaging to predict the intracranial metastatic tumor response to gamma knife radiosurgery

作者：Lee Cheng Chia; Wintermark Max; Xu Zhiyuan; Yen Chun Po; Schlesinger David; Sheehan Jason P^*

来源：Journal of Neuro-Oncology, 2014, 118(2): 351-361.

DOI：10.1007/s11060-014-1439-9

• Intracranial metastatic tumor
• Stereotactic radiosurgery
• Diffusion weighted image
• Apparent diffusion coefficient

To evaluate the effect of stereotactic radiosurgery (SRS) on intracranial metastases with diffusion-weighted 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 (ADC(T) values). The DWIT/WM ratio and ADC(T) values were assessed for correlation with the patients%26apos; 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 ADC(T) values was seen in the controlled metastases, and a decrease in ADC(T) values was seen in the metastases with poor control. The differences were significant (p value: 0.001 and 0.002, respectively). Sensitivity of a decrease in the DWIT/WM ratio to make an early prediction of tumor control was 83.9 %, and specificity was 88.5 %. When using the initial ADC(T) values of metastases to predict tumor response, sensitivity and specificity were 85.5 and 72.7 %, 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.

• 出版日期2014-6