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Title: Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Localization of Recurrent Prostate Cancer After External Beam Radiotherapy

Purpose: To compare the performance of T2-weighted (T2w) imaging and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland in the localization of recurrent prostate cancer in patients with biochemical failure after external beam radiotherapy (EBRT). Methods and Materials: T2-weighted imaging and DCE MRI were performed in 33 patients with suspected relapse after EBRT. Dynamic contrast-enhanced MRI was performed with a temporal resolution of 95 s. Voxels enhancing at 46 s after injection to a greater degree than the mean signal intensity of the prostate at 618 s were considered malignant. Results from MRI were correlated with biopsies from six regions in the peripheral zone (PZ) (base, mid, and apex). The percentage of biopsy core positive for malignancy from each region was correlated with the maximum diameter of the tumor on DCE MRI with a linear regression model. Results: On a sextant basis, DCE MRI had significantly better sensitivity (72% [21of 29] vs. 38% [11 of 29]), positive predictive value (46% [21 of 46] vs. 24% [11 of 45]) and negative predictive value (95% [144 of 152] vs. 88% [135 of 153] than T2w imaging. Specificities were high for both DCE MRI and T2w imaging (85% [144 ofmore » 169] vs. 80% [135 of 169]). There was a linear relationship between tumor diameters on DCE MRI and the percentage of cancer tissue in the corresponding biopsy core (r = 0.9, p < 0.001), with a slope of 1.2. Conclusions: Dynamic contrast-enhanced MRI performs better than T2w imaging in the detection and localization of prostate cancer in the peripheral zone after EBRT. This may be helpful in the planning of salvage therapy.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [4] ; ;  [2] ;  [5] ;  [6] ;  [2]
  1. Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto (Canada), E-mail: m.haider@utoronto.ca
  2. Radiation Medicine Program, University Health Network, Princess Margaret Hospital, Toronto (Canada)
  3. Department of Pathology, University Health Network, University of Toronto, Toronto (Canada)
  4. Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto (Canada)
  5. Department of Surgical Oncology, University Health Network, University of Toronto, Toronto (Canada)
  6. Department of Biostatistics, Princess Margaret Hospital, Toronto (Canada)
Publication Date:
OSTI Identifier:
21039750
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 70; Journal Issue: 2; Other Information: DOI: 10.1016/j.ijrobp.2007.06.029; PII: S0360-3016(07)01143-1; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BEAMS; BIOPSY; CARCINOMAS; CONTRAST MEDIA; FAILURES; NMR IMAGING; PATIENTS; PROSTATE; RADIOTHERAPY