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Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Oct 28, 2017; 9(10): 389-399
Published online Oct 28, 2017. doi: 10.4329/wjr.v9.i10.389
Lymph node imaging in initial staging of prostate cancer: An overview and update
Jessica G Zarzour, Sam Galgano, Jonathan McConathy, John V Thomas, Soroush Rais-Bahrami
Jessica G Zarzour, Sam Galgano, Jonathan McConathy, John V Thomas, Soroush Rais-Bahrami, Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35249, United States
Soroush Rais-Bahrami, Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35249, United States
Author contributions: Zarzour JG was responsible for the conception and design of the article, drafting and revision of the article, gives approval for the final version of the article, and serves as the corresponding author; Galgano S, McConathy J and Thomas JV contributed to the design of the project, participated in drafting and revising, and gives approval for the final version of the manuscript; and Rais-Bahrami S served as the supervision author, contributed to the design of the article, participated in drafting and revisions, and gives approval for the final version of the article.
Supported by Eli Lilly/Avid; AbbVie, consulting for GE Healthcare, Siemens Healthcare and Blue Earth Diagnostics.
Conflict-of-interest statement: The authors have no conflicts of interests to declare.
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: Jessica G Zarzour, MD, Department of Radiology, University of Alabama at Birmingham, JTN 357, 619 19th Street South, Birmingham, AL 35294, United States. jgzarzour@uabmc.edu
Telephone: +1-205-9343166 Fax: +1-205-9753540
Received: February 10, 2017
Peer-review started: February 15, 2017
First decision: May 7, 2017
Revised: May 26, 2017
Accepted: July 14, 2017
Article in press: July 17, 2017
Published online: October 28, 2017
Processing time: 259 Days and 0.8 Hours
Abstract

Accurate nodal staging at the time of diagnosis of prostate cancer is crucial in determining a treatment plan for the patient. Pelvic lymph node dissection is the most reliable method, but is less than perfect and has increased morbidity. Cross sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) are non-invasive tools that rely on morphologic characteristics such as shape and size of the lymph nodes. However, lymph nodes harboring metastatic disease may be normal sized and non-metastatic lymph nodes may be enlarged due to reactive hyperplasia. The optimal strategy for preoperative staging remains a topic of ongoing research. Advanced imaging techniques to assess lymph nodes in the setting of prostate cancer utilizing novel MRI contrast agents as well as positron emission tomography (PET) tracers have been developed and continue to be studied. Magnetic resonance lymphography utilizing ultra-small super paramagnetic iron oxide has shown promising results in detection of metastatic lymph nodes. Combining MRL with diffusion-weighted imaging may also improve accuracy. Considerable efforts are being made to develop effective PET radiotracers that are performed using hybrid-imaging systems that combine PET with CT or MRI. PET tracers that will be reviewed in this article include [18F]fluoro-D-glucose, sodium [18F]fluoride, [18F]choline, [11C]choline, prostate specific membrane antigen binding ligands, [11C]acetate, [18F]fluciclovine, gastrin releasing peptide receptor ligands, and androgen binding receptors. This article will review these advanced imaging modalities and ability to detect prostate cancer metastasis to lymph nodes. While more research is needed, these novel techniques to image lymph nodes in the setting of prostate cancer show a promising future in improving initial lymph node staging.

Keywords: Prostate cancer; Staging; Magnetic resonance imaging; Ultra-small super paramagnetic iron oxide; Molecular imaging; Positron emission tomography; Lymph nodes

Core tip: Accurate nodal staging at time of prostate cancer diagnosis is crucial in determining a treatment plan for the patient. This review article highlights the newest imaging techniques that have been and are being developed for imaging of lymph nodes in the initial staging of prostate cancer. Magnetic resonance lymphography utilizing ultra-small super paramagnetic iron oxide has shown to detect metastatic disease in normal sized lymph nodes. Considerable efforts are being made in molecular imaging to develop effective positron emission tomography radiotracers that may be combined with computed tomography or magnetic resonance to detect prostate metastasis as well as potential therapeutic applications.