|Prostate Cancer: Evolving Detection Techniques|
Young Investigator Award Finalist: Magnetic Resonance
Diffusion Characteristics of Histologically Defined Prostate Cancer in
Junqian Xu1, Peter A. Humphrey1, Adam S. Kibel1, Abraham Z. Snyder1, Vamsidhar R. Narra1, Joseph JH Ackerman1, Sheng-Kwei Song1
1Washington University, St. Louis, Missouri, USA
Increased cellularity, and hence decreased luminal spaces, in peripheral zone PCa led to about 40% and 50% ADC decrease compared to benign peripheral zone tissues in vivo and ex vivo, respectively. In contrast, no significant diffusion anisotropy differences were observed between the cancerous and non-cancerous peripheral zone tissues. However, the dense fibromuscular tissues in prostate, such as stromal tissues in benign prostatic hyperplasia (BPH) in central gland, exhibited high diffusion anisotropy. PCa identified in volume rendered diffusion sensitive MR images correlates well with histologically determined PCa foci.
Reproducibility of Quantitative and Semi-Quantitative
Dynamic and Intrinsic Susceptibility-Weighted Parameters of the
Cancerous Human Prostate Gland
Roberto Alonzi1, Jane Taylor1, Peter Hoskin1, James Stirling1, James d'Arcy2, Ben Wilton2, David Collins2, Michele Saunders1, Anwar Padhani1
1Mount Vernon Hospital, Northwood, UK; 2Institute of Cancer Research, Sutton, UK
Quantitative functional MRI techniques are increasingly being used in the assessment of the malignant prostate gland. For these techniques to have clinical application, their reproducibility needs to be established. 20 patients with prostate cancer that were due to be treated with neo-adjuvant androgen deprivation (AD) prior to radical radiotherapy underwent 2 paired MRI investigations; two prior to the commencement of and two scans after three months of AD. This study is the first to document the variability and reproducibility of T1-and T2*-weighted DCE-MRI and R2* for the benign and malignant human prostate gland.
Correlation of ADC and T2 with Cell
Density in Prostate Cancer at 3.0T
Peter Gibbs1, Gary P. Liney1, Martin D. Pickles1, Bashar Zelhof1, Greta Rodrigues2, Lindsay W. Turnbull1
1University of Hull, Hull, UK; 2Hull and East Yorkshire NHS Trust, Hull, UK
Prostate cancer rates have risen dramatically over the last few years and MRI is increasingly used in this area. With a diagnostic accuracy of only around 70% conventional high spatial resolution and dynamic contrast enhanced imaging has been supplemented with DWI and T2 mapping. However, there has been little investigation of the diagnostic potential of these parameters via correlation with pathological data. This work concentrates on comparing cell density determined from hematoxylin and eosin staining with ADC and T2 values.
The Impact of Intermixed Normal Peripheral Zone
Elements on the Measurement of Apparent Diffusion Coefficient and T2 in
Deanna Lyn Langer1, 2, Theodorus H. van der Kwast1, 3, Andrew J. Evans1, Laibao Sun4, Martin J. Yaffe, 24, John Trachtenberg1, Masoom A. Haider1, 2
1University Health Network, Toronto, Canada; 2University of Toronto, Toronto, Canada; 3Mount Sinai Hospital, Toronto, Canada; 4Sunnybrook Health Sciences Centre, Toronto, Canada
The impact of normal peripheral zone (PZ) tissue components within prostate cancers on ADC and quantitative T2 values was investigated. Whole mount sections were compared to MRI. PZ cancers were classified as sparse or dense according to the percentage of normal PZ tissue in the tumor. ADC and T2 values from ROIs in normal PZ, dense cancers and sparse cancers were compared. There were no statistically significant differences seen between normal PZ and sparse cancers for absolute values or contrast (tumor to normal ratio) measurements in both ADC and T2, whereas normal PZ was significantly higher than dense cancer. The percentage of normal PZ within a tumor may affect the detection and delineation of prostate cancer.
Sensitivity and Specificity of Functional MRI to Map
Tumour Hypoxia in the Human Prostate Gland
Roberto Alonzi1, Anwar Padhani1, Jane Taylor1, James Stirling1, Ben Wilton2, James d'Arcy2, David Collins2, Michele Saunders1, Peter Hoskin1
1Mount Vernon Hospital, Northwood, UK; 2Institute of Cancer Research, Sutton, UK
A study in 17 patients with prostate cancer evaluating the value of incorporating Dynamic Susceptibility Contrast (DSC) MRI based blood volume measurements with BOLD imaging to detect tumour hypoxia. Patients were imaged with BOLD and DSC MRI prior to radical prostatectomy. Hypoxia was determined using pimonidazole immunohistochemistry. The sensitivity and specificity for hypoxia detection was 80% and 77% respectively
Assessment of Different Quantification Approaches of
DCE-MRI in Prostate Cancer at 3T
Guang Jia1, Xiangyu Yang1, Yukihisa Takayama1, Steffen Sammet1, Zarine K. Shah1, Ketul K. Shah1, Pankaj Dangle1, Wenle P. Wang1, Rafael E. Jimenez1, Vipul R. Patel1, Michael V. Knopp1
1The Ohio State University, Columbus, Ohio, USA
Improving the non-invasive capabilities of cancer delineation might be achieved by dynamic contrast-enhanced MRI at high field. 27 patients with clinically proven prostate cancer were imaged at 3T without using an endorectal coil. 3 different methods including semi-quantitative parameters, adjusted Brix’s model and Larsson’s model were applied to the ROIs from tumor, non-cancerous peripheral zone, central gland. All parameters could differentiate tumor from the non-cancerous peripheral zone. However, only tmax, washout-score, kep could differentiate tumor from central gland. In conclusion, DCE-MRI at 3T is capable of non-invasively detecting prostate cancer especially from the central gland by selecting appropriate parameters.
Functional MR Parameters of Histopathologically
Indentified Prostate Tissues
Sophie F. Riches1, Veronica A. Morgan1, Geoffrey S. Payne1, Cyril Fisher2, S Sandhu2, David J. Collins1, Nandita M. deSouza1
1Royal Marsden NHS Trust & Institute of Cancer Research, Sutton, UK; 2Royal Marsden NHS Trust, London, UK
20 patients were imaged prior to prostatectomy using diffusion imaging, contrast enhanced MRI and 1H spectroscopy. Histopathology-defined tumour regions were transferred onto parametric maps to obtain values for normal and tumour tissue for T2 intensity, apparent diffusion coefficient, area under the contrast uptake curve, contrast volume transfer coefficient, reflux rate constant and the ratio of choline to citrate peak area. Significant differences were identified between the mean functional parameters of tumour and combined non tumour tissue, and between tumour and normal peripheral zone. No difference was found between tumour and normal central gland unless small tumour regions were excluded.
Magnetic Resonance Spectroscopic Imaging and Dynamic
Contrast Enhanced Prostate MRI: Correlation with Histopathology
Bao Zhang1, Steve Roys1, Khan Siddiqui2, Danielle Holanda, John Papadimitriou, James Borin, Michael Naslund, Eliot Siegel, Rao P. Gullapalli
1University of Maryland, Baltimore, Maryland, USA; 2VA Maryland Health Care System, Baltimore, Maryland, USA
Conventional magnetic resonance (MR) imaging, along with 3D-MR spectroscopy imaging (MRSI) and dynamic contrast enhanced (DCE) MRI were performed on fourteen patients with biopsy proven prostate cancer prior to prostatectomy. Parameters derived from these techniques were compared with step section histopathology. Results showed that both techniques are able to distinguish cancerous tissue from normal but they however lacked sensitivity to tumor grade. Receiver operating characteristic (ROC) based statistical analysis revealed a positive predictive value of 0.95 and 0.94 respectively and an overall accuracy of 72% and 65% respectively.
Comparison of Transceive Endorectal and External
Surface Array Coils for Prostate Imaging at 7 Tesla
Gregory John Metzger1, Carl J. Snyder1, Can Akgun1, Gregor Adriany1
1University of Minnesota, Minneapolis, Minnesota, USA
Previous work by our group addressed the challenges associated with performing ultra high field prostate imaging with external transceive surface arrays. In this abstract, we pursue a preliminary study which investigates how the external coil array performs against a transceive endorectal coil (ERC) at 7 Tesla. It was found that the ERC produced the expected gains in SNR along with improved anatomic detail on T2w TSE imaging. While improvements in image quality were observed the challenges of managing the large transmit B1 homogeneities of a local transceive coil requires further investigation.