Prostate Cancer
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Thursday 10 May 2012
Room 210-211  10:30 - 12:30 Moderators: Tom W. J. Scheenen, Hebert A. Vargas

10:30 0544.   
In vivo measurement of T1 and T2 relaxation times in healthy human prostate at 7T
Marnix C. Maas1, Miriam W. Lagemaat2, Stephan Orzada3,4, Thiele Kobus2, Oliver Kraff3, Stefan Maderwald3, Andreas K. Bitz3,4, Mark E. Ladd3,4, and Tom W.J. Scheenen2,3
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 2Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, GLD, Netherlands, 3Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, 4Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany

Knowledge of T1 and T2 relaxation times can aid the development and optimization of dedicated pulse sequences for imaging and spectroscopy at ultra-high field (≥7T). We have measured these quantities in human prostate and surrounding tissues at 7T in healthy volunteers using progressive saturation gradient echo imaging with fixed TR and varying flip angle for T1 and multiple-contrast spin-echo imaging for T2. The results suggested a TE of 60–70 ms for optimum contrast between the prostate peripheral zone and transition zones in fast spin-echo imaging, which was indeed shown to yield contrast between these tissues.

10:42 0545.   MR T1lower case Greek rho Imaging on Human Prostate Cancer
Xiang He1, Serter Gumus1, Ayaz Aghayev1, Jie Zheng2, and Kyongtae Ty Bae1
1Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Mallinckrodt Institute of Radiology, Washington University in St Louis, St Louis, Missouri, United States

In this study, we developed and applied a T1ρ sequence to image the prostate in healthy normal controls and patients. Our results demonstrated that T1ρ quantification is feasible in 3T MR scanner without the utilization of an endorectal coil. While peripheral zone T2 and T1ρ maps were often homogenous in healthy control subjects, large regional heterogeneity can been also observed due to the variations on granular structure. The discrepancy of T2 and T1ρ behavior in prostate peripheral lesion area in patients is likely due to increased cellular content. This may provide additional information to improve the diagnosis of prostate cancer.

10:54 0546.   Sodium Imaging of the Prostate at 3T
Daniel Hausmann1, Simon Konstandin2, Frank G Zöllner2, Stefan Haneder1, Friedrich Wetterling2, Armin M Nagel3, Dietmar J Dinter1, Stefan O Schönberg1, and Lothar R Schad2
1Institute of Clinical Radiology and Nuclear Medicine, University Medicine Mannheim, Mannheim, Germany, 2Computer Assisted Clinical Medicine, University Medicine Mannheim, Mannheim, Germany, 3Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany

The mutiparametric MR imaging approach of the prostate involves functional sequences to increase the specificity of the evaluation of prostatic lesions. The purpose of this study was to evaluate the feasibility of 23Na imaging and the feasibililty of quantification as a tool of possible additional value for multiparametric imaging of the prostate in a clinical setting in human volunteers at 3 T. Eight volunteers 23-34 years old (mean = 28 years) were enrolled. This study suggests that sodium imaging on a clinical 3T scanner might be an appropriate, noninvasive method for imaging of the human prostate. Further developments of the coil systems are necessary to increase spatial resolution, to reduce examination time and to enable a more accurate and reliable quantification. Moreover, clinical studies are necessary to evaluate if changes of the sodium levels are apparent in prostate cancer.

11:06 0547.   Diagnostic modelling of multi-parametric MRI as a radiological tool to predict transition zone prostate cancer
Nikolaos Dikaios1, Taiki Fujiwara2, Mohamed Abd Alazeez3, David Atkinson4, and Shonit Punwani2
1Department of Medical Physics and Bioengineering, University College London, London, Greater London, United Kingdom, 2Department of Radiology, University College London Hospital, 3Department of Urology, University College London Hospital, 4Centre for Medical Imaging, University College London

Multi-parametric MRI has a reported sensitivity of 73% and specificity of 89% for detection of tumour within the peripheral zone of the prostate. However, benign prostatic hypertrophy as commonly found in the transition zone produces signal changes that make the radiologists detection of anterior gland tumour more difficult. Our study derived a predictive model for classification of suspected sites of anterior gland disease based on clinical (age, PSA, gland volume, PSA density), quantitative MRI parameters (ADC, contrast enhanced, T2 image signal) and textural features of MR images (entropy, contrast, co-occurance); and compared the performance of this model for detection of tumour against a consensus radiologist opinion.

11:18 0548.   Assessment of abnormal ADC matched voxels with DCE parameters for characterization of prostate cancer at 3T
Fiona M Fennessy1,2, Andriy Fedorov1, Sandeep N Gupta3, William M Wells1, Robert V Mulkern1,4, and Clare M Tempany1
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Radiology, Dana Farber Cancer Institute, Boston, MA, United States, 3GE Global Research Center, Niskayuna, NY, United States, 4Radiology, Children's Hospital Boston, Boston, MA, United States

We sought to determine if Ktrans and ve differed within ADC-matched prostate tumor voxels, confirmed by pathology at radical prostatectomy. A deformable registration technique was used to recover image distortions on DWI, registered to the DCE series. We found a significant difference between tumor and normal tissue for ADC, Ktrans , and ve. Using Logistic regression analysis, Ktrans has a contributory role to ADC for tumor detection. However, weak correlations between both Ktrans and ve and the ADC values, underscoring the different pathophysiological processes assessed with DWI and DCE, and need for a multiple-parameter strategy approach for prostate tumor assessment.

11:30 0549.   Diffusion tensor magnetic resonance tractography of the prostate: feasibility for mapping neurovascular anatomy
Daniel Jason Aaron Margolis1, Benjamin Ellingson2, Shyam Natarajan3, Robert Reiter4, Taryar Zaw1, Peter Schulam4, Steven Raman1, and David Finley5
1Department of Radiology, UCLA David Geffen School of Medicine, Los Angeles, CA, United States, 2Department of Radioloyg, UCLA David Geffen School of Medicine, 3Department of Bioengineering, UCLA David Geffen School of Medicine, Los Angeles, CA, United States, 4Department of Urology, UCLA David Geffen School of Medicine, 5Department of Urology, Kaiser Permanente Los Angeles

Eight men scheduled to prostatectomy underwent endorectal multiparametric magnetic resonance imaging (MRI) of the prostate with DTI. DTI tractography was successfully performed in all eight patients, visualizing fiber tracts around the prostate. DTI tractography of the prostate effectively visualized periprostatic fiber tract anatomy. Variation in tract distribution existed within individual patients and between patients. Some patients had disproportionately tract mass from one side of the prostate to the other. These findings have potential applicability for the generation of patient-specific pre-operative nerve sparing plans for RP and for the quantitative evaluation of potency outcomes.

11:42 0550.   
Fast Real-Time Tracking Using a POCC Algorithm for 3T MR-Guided Transrectal Prostate Biopsy: A Feasibility Study.
Patrik Zamecnik1, Martijn Schouten2, Axel Krafft3, Florian Maier4, Heinz-Peter Schlemmer5, Jelle O. Barentsz6, Michael Bock7, and Jurgen J. Fütterer6
1Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, Germany, 2Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 3Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, United States, 4Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 5Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany,6Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 7Medical Physics, Dept. of Radiology, University Hospital Freiburg, Freiburg, Germany

In this feasibility study a safe, easy and precise instrument guidance using the POCC based sequence for automatic needle-guide tracking in transrectal 3 T MR-guided prostate biopsies was demonstrated. The combination of very easy handling, good tumor detection rates comparable with other MR-guided prostate biopsy techniques, use of standard, commercial available devices and short procedure times is very promising and making this approach attractive for clinical routine.

11:54 0551.   Comparison of TRUS vs. MRI guided biopsy in MRI apparent prostate cancers: Preliminary Results
Adam J Jung1, Fergus V. Coakley2, Antonio C. Westphalen3, Daniel B. Vigneron3, and John Kurhanewicz4
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, 3Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 4University of California San Francisco

The primary socioeconomic challenge in caring for patients with prostate cancer is our limited ability to accurately characterize the disease as indolent or aggressive at the time of presentation, and stratify management from active surveillance through definitive surgery or radiation accordingly. A major contributing factor to this problem is the known inaccuracy in disease detection and characterization by systematic transrectal ultrasound-guided biopsy, even though this is the current standard of care for diagnosis. We demonstrate that multiparametric MRI supplemented by MRI-guided biopsy can improve both disease detection and characterization, and may ultimately improve our ability to deliver personalized patient care in men with prostate cancer.

12:06 0552.   Prostate cancer detection rate: MRSI directed TRUS biopsy versus increasing number of cores in clinically challenging group of men with PSA in the gray zone of 4-10 ng/ml
Durgesh Kumar Dwivedi1, Tarun Javali2, Rajeev Kumar2, Sanjay Thulkar3, Sanjay Sharma3, Amit K. Dinda4, 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

Raised serum prostate specific antigen (PSA) may not reflect the presence of prostate cancer (PCa) and transrectal ultrasound (TRUS) has limited sensitivity in PCa detection. MRSI has the potential to detect PCa based on metabolic differences. We performed a retrospective case controlled study on 278 men prior to biopsy with PSA in the range of 4-10 ng/ml. Our study revealed that MRSI directed TRUS biopsy increases PCa detection rate (2.9 times) compared to standard TRUS guided core (6 or 12) biopsy in patients with PSA in the range of 4-10 ng/ml.

12:18 0553.   Biologically-guided radiation treatment of the prostate using 1H-MRSI permission withheld
Niranjan Venugopal1,2, Lawrence Ryner3,4, Keith Nakonechny2, and Boyd McCurdy2,4
1Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada, 2Medical Physics, CancerCare Manitoba, Winnipeg, Manitoba, Canada,3National Research Council Institute for Biodiagnostics, 4Physics and Astronomy, University of Manitoba

Using intensity modulated radiation therapy (IMRT), we can now accurately deliver radiation doses to dominant intraprostatic lesions as identified by 1H-MRSI. Using a modified tumour control probability (TCP) formalism, which includes the 1H-MRSI data, we determine the optimal dose distribution that would enable equivalent control of the prostate cancer by escalating the dose to the localized DIL. The TCP and normal tissue complication probability (NTCP) for both plans were calculated, and compared. The result of this study indicates that optimizing the dose to the prostate according to 1H-MRSI information is possible, and that it can be used to logically derive new prescription doses leading to improved TCP.