Xingchen Wu1,2,3, Petri Reinikainen4, Mika Kapanen4,5, Tuula Vierikko3, Pertti Ryymin3,5, Pirkko-Liisa Kellokumpu-Lehtinen4,2. 1. Department of Oncology, Medical Imaging Centre, Tampere University Hospital, Tampere, Finland Xingchen.Wu@uta.fi. 2. Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland. 3. Department of Radiology, Medical Imaging Centre, Tampere University Hospital, Tampere, Finland. 4. Department of Oncology, Medical Imaging Centre, Tampere University Hospital, Tampere, Finland. 5. Department of Medical Physics, Medical Imaging Centre, Tampere University Hospital, Tampere, Finland.
Abstract
BACKGROUND: Diffusion-weighted imaging (DWI) with measurement of apparent diffusion coefficient (ADC) allows for assessment of tumor aggressiveness. The objective of this study was to evaluate the changes of ADC value in prostate cancer after volumetric-modulated arc radiotherapy (VMAT) and to identify magnetic resonance imaging (MRI) biomarkers for monitoring tissue changes after radiotherapy. PATIENTS AND METHODS: Thirty-seven patients with biopsy-proven prostate cancer treated with VMAT underwent serial MRI examinations including DWI before radiotherapy, and at 3 and 12 months after radiotherapy. ADC values of the tumor and healthy prostate tissue were measured and compared at these three time points. RESULTS: The tumor ADC value increased significantly 3 months after radiotherapy (p<0.0001). There was a further increase of tumor ADC from 3 to 12 months after radiotherapy (p<0.01). The ADC of healthy prostate tissue did not show any significant changes. CONCLUSION: The ADC value is a useful biomarker for evaluating the efficacy of radiotherapy in prostate cancer. Copyright
BACKGROUND: Diffusion-weighted imaging (DWI) with measurement of apparent diffusion coefficient (ADC) allows for assessment of tumor aggressiveness. The objective of this study was to evaluate the changes of ADC value in prostate cancer after volumetric-modulated arc radiotherapy (VMAT) and to identify magnetic resonance imaging (MRI) biomarkers for monitoring tissue changes after radiotherapy. PATIENTS AND METHODS: Thirty-seven patients with biopsy-proven prostate cancer treated with VMAT underwent serial MRI examinations including DWI before radiotherapy, and at 3 and 12 months after radiotherapy. ADC values of the tumor and healthy prostate tissue were measured and compared at these three time points. RESULTS: The tumor ADC value increased significantly 3 months after radiotherapy (p<0.0001). There was a further increase of tumor ADC from 3 to 12 months after radiotherapy (p<0.01). The ADC of healthy prostate tissue did not show any significant changes. CONCLUSION: The ADC value is a useful biomarker for evaluating the efficacy of radiotherapy in prostate cancer. Copyright