Veronica A. Morgan1, Sharon L. Giles1, Sophie F. Riches1, David Dearnaley2, Nandita M. deSouza1
1CRUK & EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; 2Academic Urology, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom
This study evaluates the accuracy of T2W plus DW-MRI for detecting recurrent tumor within the prostate following External Beam Radiotherapy (EBRT). Mean ADC measurements of tumor and irradiated non-tumor tissue, confirmed by TRUS biopsy, were documented in 26 patients with evidence of biochemical failure. ADCs of MRI-defined tumor, histology-defined tumor and non-tumor irradiated tissue were compared. Mean ADC for both MRI and histology defined tumor were significantly lower than for non-tumor irradiated tissue. A cut-off ADC of 1337 (x10-6mm2/s) predicted tumor with a 92.9% sensitivity and 100% specificity. DWI MRI can be used for identifying tumor recurrence following EBRT.