Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Apr 28, 2016; 8(4): 397-402
Published online Apr 28, 2016. doi: 10.4329/WJR.v8.i4.397
Quantitative study of prostate cancer using three dimensional fiber tractography
Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani
Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States
Alexey Tonyushkin, Department of Physics, UMass, Boston, MA 02125, United States
Author contributions: Hedgire S, Tonyushkin A, Kilcoyne A and Harisinghani M contributed equally to this work; Hedgire S, Tonyushkin A and Kilcoyne A collected and analyzed the data, and drafted the manuscript; Efstathiou JA, Hahn PF and Harisinghani M provided analytical oversight; Hedgire S, Tonyushkin A, Kilcoyne A, Efstathiou JA, Hahn PF and Harisinghani M designed and supervised the study; Hedgire S, Tonyushkin A, Kilcoyne A and Harisinghani M revised the manuscript for important intellectual content; Kilcoyne A, Tonyushkin A, Efstathiou JA and Hahn PF offered the technical or material support; Hedgire S and Harisinghani M provided administrative support; all authors have read and approved the final version to be published.
Supported by Mac Erlaine Research Scholarship, St. Vincents University Hospital, Dublin, Ireland (to Dr. Aoife Kilcoyne).
Institutional review board statement: The study was reviewed and approved by the Massachusetts General Hospital Institutional Review Board.
Informed consent statement: Institutional review board waived requirement for informed consent. Consent was not obtained but the presented data are anonymised and risk of identification is low.
Conflict-of-interest statement: The authors report no conflict of interest.
Data sharing statement: Technical appendix, statistical code and dataset available from the corresponding author at hedgire.sandeep@mgh.harvard.edu. Informed consent was not required as per the IRB approval. The presented data are anonymised and the risk of identification is low.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Sandeep Hedgire, MD, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, United States. hedgire.sandeep@mgh.harvard.edu
Telephone: +1-617-7268073 Fax: +1-617-7264891
Received: August 14, 2015
Peer-review started: August 16, 2015
First decision: November 7, 2015
Revised: January 15, 2016
Accepted: February 14, 2016
Article in press: February 16, 2016
Published online: April 28, 2016
Abstract

AIM: To investigate feasibility of a quantitative study of prostate cancer using three dimensional (3D) fiber tractography.

METHODS: In this institutional review board approved retrospective study, 24 men with biopsy proven prostate cancer underwent prostate magnetic resonance imaging (MRI) with an endorectal coil on a 1.5 T MRI scanner. Single shot echo-planar diffusion weighted images were acquired with b = 0.600 s/mm2, six gradient directions. Open-source available software TrackVis and its Diffusion Toolkit were used to generate diffusion tensor imaging (DTI) map and 3D fiber tracts. Multiple 3D spherical regions of interest were drawn over the areas of tumor and healthy prostatic parenchyma to measure tract density, apparent diffusion coefficient (ADC) and fractional anisotropy (FA), which were statistically analyzed.

RESULTS: DTI tractography showed rich fiber tract anatomy with tract heterogeneity. Mean tumor region and normal parenchymal tract densities were 2.53 and 3.37 respectively (P < 0.001). In the tumor, mean ADC was 0.0011 × 10-3 mm2/s vs 0.0014 × 10-3 mm2/s in the normal parenchyma (P < 0.001). The FA values for tumor and normal parenchyma were 0.2047 and 0.2259 respectively (P = 0.3819).

CONCLUSION: DTI tractography of the prostate is feasible and depicts congregate fibers within the gland. Tract density may offer new biomarker to distinguish tumor from normal tissue.

Keywords: Prostate cancer, Tract density, Diffusion tensor imaging, Tractography, Magnetic resonance imaging

Core tip: Our study identified 24 men with biopsy proven prostate cancer. These patients underwent prostate magnetic resonance imaging with an endorectal coil on a 1.5 T scanner. Software was used to generate a diffusion tensor imaging (DTI) map and three dimensional fiber tracts. DTI tractography demonstrated rich fiber tract anatomy with tract heterogeneity. Tract density may represent a new biomarker to distinguish tumor from normal tissue.