ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Prostate: Clinical
Monday 22 April 2013
Room 355 BC  14:15 - 16:15 Moderators: Jurgen J. Fütterer , Daniel J. A. Margolis

14:15 0091.   MRI-US Fused Targeted Prostate Biopsy Detects Clinically Significant Cancer in Active Surveillance Patients Better Than 12 Core Random Biopsy with Less Than 4 Cores
Michael Da Rosa1,2, Laurent Milot1,3, Linda Sugar3,4, Danny Vesprini3,5, Hans Chung3,5, Andrew Loblaw3,5, Laurence Klotz3,6, and Masoom A. Haider1,3
1Department of Medical Imaging, University of Toronto, Toronto, ON, Canada, 2Institute of Medical Science, University of Toronto, Toronto, ON, Canada,3Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 4Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada, 5Radiation Oncology, University of Toronto, Toronto, ON, Canada, 6Division of Urology, University of Toronto, Toronto, ON, Canada

The purpose of this prospective study was to determine the ability of an MRI-US fusion biopsy system to detect clinically significant (CS) disease in active surveillance (AS) patients compared to random transrectal ultrasound (R-TRUS) guided biopsy (bx). Multiparametric MRI prospectively identified up to 4 suspicious targets in each patient. Biopsy was performed using an MRI-ultrasound navigation system (UroNav, Philips Healthcare). MRI-US fusion biopsy detected more CS cancers with fewer biopsy cores than random biopsy in AS patients. In addition, MRI in AS patients has a high negative predictive value for the presence of CS disease on subsequent biopsy.

14:27 0092.   Validation Study of ESUR Prostate MR Guidelines 2012: The Significance of Different Sequences of Multi-Parameter MRI in Detection of Prostate Cancer in 106 Consecutive Patients
Juan Hu1, He Wang1, Xuedong Yang1, Chengyan Wang2, Rui Wang1, Ge Gao1, Hui Zhang2, Wenchao Cai1, Wei Wang1, Jue Zhang2,3, and Xiaoying Wang1,2
1Radiology Department, Peking University First Hospital, Beijing, Beijing, China, 2Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, Beijing, China, 3College of Engineering, Peking University, Beijing, Beijing, China

Multi-parameter MRI (Mp-MRI) plays an increasingly important role in the detection, localization and staging of prostate cancer (PCa). To solve the absence of unified criterion of technique and the interpretation of images of Mp-MRI in PCa detection. A recent consensus meeting of PCa experts from ESUR recommended PI-RADS scoring system. True evidence-based guidelines could not be formulated. Our retrospective study proved that PI-RADS scoring was an operable and useful scoring system for interpretation of Mp-MRI used in PCa detection. The diagnostic status of each MR sequence was not at the same level. Only appropriate combined mode was used, the excellent diagnostic efficacy of Mp-MRI can be obtained.

14:39 0093.   
Derivation and Comparison of Site Specific Peripheral and Transition Zone Quantitative DCE MRI Logistic Regression Models for Prostate Cancer Detection: Does Cancer Location Matter?
Nikolaos Dikaios1, Mohamed Abd Alazeez2, Mark Emberton2, Taiki Fujiwara3, David Atkinson1, and Shonit Punwani1
1Centre for Medical Imaging, University College London, London, Greater London, United Kingdom, 2Department of Urology, University College London Hospital, London, Greater London, United Kingdom, 3Department of Radiology, University College London Hospital, London, Greater London, United Kingdom

Dynamic contrast enhancement (DCE) MRI has been advocated for detection of prostate cancer, but studies predominantly concentrate on peripheral zone tumours. Biological differences are known to exist between tumours within transition and peripheral zones due to their different microenvironment. This study aims to compare and contrast quantitative DCE MRI parameters of prostate PZ and TZ cancer and non-cancer regions; to identify those best able to classify cancer tissue at each site and thereby improve DCE MRI based diagnostic models used within computer aided detection software.

14:51 0094.   Computed Diffusion-Weighted Imaging of the Prostate at 3T: Impact on Image Quality and Tumor Detection
Andrew B. Rosenkrantz1, Nicole Hindman1, Hersh Chandarana1, Fang-ming Deng2, James S. Babb1, Samir S. Taneja3, and Christian Geppert4
1Radiology, NYU Langone Medical Center, New York, New York, United States, 2Pathology, NYU Langone Medical Center, New York, New York, United States,3Urologic Oncology, NYU Langone Medical Center, New York, New York, United States, 4Siemens Medical Systems, New York, New York, United States

49 prostate cancer patients underwent 3T MRI including DWI with b-values 50 and 1000 mm2/sec. Computed DW-images with b-value 1500 were generated from the lower b-value images without additional scan time. Directly acquired b1500 images were also obtained in 39 patients. For two independent readers, using prostatectomy as reference, computed b-1,500 images had higher sensitivity and PPV for tumor than direct b-1,000 images and no significant difference than direct b-1,500 images. Scores for diagnostic confidence, tumor conspicuity, distortion, and benign prostate tissue suppression, were also significantly better for computed b-1,500 images than for direct b-1,000 images for both readers.

15:03 0095.   Contrast Dispersion Mapping in DCE MRI: A New Option for Prostate Cancer Detection
Massimo Mischi1, Kyveli Kompatsiari1, Tamerlan Saidov1, Marc Engelbrecht2, Hessel Wijkstra1,2, and Marcel Breeuwer1,3
1Eindhoven University of Technology, Eindhoven, Netherlands, 2Academic Medical Center, Amsterdam, Netherlands, 3Philips Healthcare, Best, Netherlands

A new method is proposed for characterization of the microvascular architecture by assessment of contrast intravascular dispersion in dynamic contrast enhanced MRI. Dispersion is estimated by fitting a new model that integrates the Tofts model for permeability estimation together with a solution of the convective dispersion equation. Based on the link between angiogenesis and cancer growth, this method is evaluated for localization of prostate cancer by comparison with histology results following radical prostatectomy. Without need for an arterial input function, MR dispersion imaging enables the simultaneous generation of dispersion and permeability maps. Promising preliminary results in 7 patients are reported.

15:15 0096.   
Hybrid T2 and Diffusion Weighted MRI for Prostate Cancer Detection
Shiyang Wang1, Yahui Peng1, Milica Medved1, Ambereen Yousuf1, Marko Ivancevic2, Ibrahim Karademir1, Yulei Jiang1, Tatjana Antic3, Steffen Sammet1, Aytek Oto1, and Gregory S. Karczmar1
1Radiology, University of Chicago, Chicago, IL, United States, 2MR clinical science, Philips Healthcare, Cleveland, OH, United States, 3Pathology, University of Chicago, Chicago, IL, United States

A novel, hybrid MR imaging method was implemented for prostate cancer detection. The proposed hybrid imaging acquires diffusion weighted MRI (DWI) data at three echo times (TE’s), and allows calculation of ADC and T2 as functions of TE and diffusion weighting factor (b-value), respectively. Preliminary results showed that both ADC and T2 calculated from the hybrid imaging data can help differentiate normal tissue regions and cancer foci. ADC at higher TE showed better differentiation than ADC at lower TE. The two dimensional 1/T2 map improved separation of cancer and normal voxels relative to a 1D comparison.

15:27 0097.   1 H MRSI of Prostate Cancer Incorporating Spermine in the Quantification, a 7 Tesla Patient Study
Mariska P. Luttje1, Robin A. de Graaf2, Catalina S. Arteaga de Castro1, Peter R. Luijten1, Marco van Vulpen1, Uulke A. van der Heide3, and Dennis W.J. Klomp1
1Imaging Division, Univerity Medical Center, Utrecht, Netherlands, 2MRRC, Yale University, New Haven, CT, United States, 3Department of Radiotherapy, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands

In this study at 7T, we show the influence of polyamines in the variability of the cho+pa+cr/cit vs cho+cr/cit ratio by using spectral fitting with simulated basissets at 7T instead of the commonly used signal integration when including more than 200 MR spectra obtained from six patients diagnosed with prostate cancer. Ratios excluding the fitted polyamines resonances show a clear trend towards less spread over the voxels (tumor as well as healthy).

15:39 0098.   
Stratification of Disease Aggressiveness of Prostate Cancer Using MRSI and DWI
Durgesh Kumar Dwivedi1, Girdhar Bora2, Rajeev Kumar2, Sanjay Thulkar3, Sanjay Sharma3, Siddhartha D. Gupta4, and Naranamangalam R. Jagannathan1
1Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of Urology, All India Institute of Medical Sciences, New Delhi, Delhi, India, 3Department of Radio-diagnosis, All India Institute of Medical Sciences, New Delhi, Delhi, India, 4Department of Pathology, All India Institute of Medical Sciences, New Delhi, Delhi, India

The challenge to clinicians in the management of prostate cancer (PCa) patients is the in vivo assessment of disease aggressiveness. TRUS biopsy detects the PCa and determines the Gleason score. Identification of patients with more-aggressive disease would help to prevent overtreatment of those with low-risk tumors. Our results showed the reduction of metabolite ratios [Cit/(Cho+Cr)] and ADC values with the increase of Gleason score. The present study indicates that MRSI and DWI could stratify the PCa disease aggressiveness non-invasively.

15:51 0099.   
MR Spectroscopic Imaging of Prostate Cancer: Metabolism or Morphology?
Thiele Kobus1, Jeroen Van der Laak2, Caroline Bruggink1, Christina Hulsbergen-Van de Kaa2, Tom W.J. Scheenen1, and Arend Heerschap1
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, 2Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands

Variations in the signal intensity of citrate and other metabolites in 1H MRSI of the prostate may be caused by changes in luminal volume. This was investigated for cancer containing prostates by correlating signal intensities with morphological features of digitally segmented histopathological slices. A significant relation was found between the Cho+Spm+Cr/Cit ratio and the %area-of-nuclei / %-area-of-lumen, obtained from HE stained slices of prostatectomy samples. This study indicates that changes in the signal of Cit (and possibly of other metabolites) in PCa result from morphological alterations, rather than changes in metabolism.

16:03 0100.   Planning a Boosted Radiotherapy Dose to the Dominant Intraprostatic Tumour Lesion Within the Prostate as Defined by Multifunctional MR Parameters
Sophie F. Riches1, Geoffrey S. Payne1, Nandita M. deSouza1, Scott Morgan2, David Dearnaley3, Veronica A. Morgan1, Sharon L. Giles1, and Mike Partridge4
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, 2Division of Radiation Oncology, University of Ottawa, Ottawa, Ontario, Canada, 3Division of Radiotherapy & Imaging, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, 4Gray Institute for Radiation Oncology and Biology,Department of Oncology, University of Oxford, Oxford, Oxfordshire, United Kingdom

The use of a boosted radiation dose to a tumour nodule within the prostate is limited by poor accuracy for tumour localisation on morphological imaging; functional imaging offers more accurate delineation of the dominant intraprostatic lesion. This study uses a model that combines multifunctional MR parameters to define an intraprostatic lesion and plans an 84 Gy radiation boost to functional imaging-defined tumour with IMRT. Compared to a standard clinical treatment of 72 Gy applied uniformly across the prostate, a focal boost resulted in a greater therapeutic ratio, with potentially greater tumour control and fewer side-effects from the treatment.