Application of diffusion-weighted magnetic resonance imaging to predict the intracranial metastatic tumor response to gamma knife radiosurgery.
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 DWI(Tumor/white matter) ratios (DWI(T/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 DWI(T/WM) ratio and ADCT values were assessed for correlation with the patients' tumor response, brain edema, and survival. A decrease in DWI(T/WM) ratios was seen in the controlled metastases, and an increase in the DWI(T/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: 0.001 and 0.002, respectively). Sensitivity of a decrease in the DWI(T/WM) ratio to make an early prediction of tumor control was 83.9%, and specificity was 88.5%. When using the initial ADCT 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.
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA.|Department of Neurosurgery Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Cheng-Chia
CC
Lee
Neuroradiology Division, Department of Radiology, University of Virginia Health System, Charlottesville, VA, USA.
Max
M
Wintermark
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA.
Zhiyuan
Z
Xu
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA.
Chun-Po
CP
Yen
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA.
David
D
Schlesinger
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA. jps2f@virginia.edu.|Departments of Radiation Oncology, Neurological Surgery, and Neuroscience, University of Virginia Health System, PO Box 800212, Charlottesville, VA, 22908, USA. jps2f@virginia.edu.
Jason P
JP
Sheehan
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000209:etiology / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D066127:White Matter / Q000473:pathology / Q000601:surgery