The clinical value of dynamic contrast-enhanced magnetic resonance imaging at 3.0T to detect prostate cancer

Xuhui Zhang 0 2 Xianyue Quan 0 2 Shilong Lu 0 2 Fanheng Huang 0 2 Jianming Yang 0 2 Queenie Chan 0 1 Ting Lin 0 2 0 >> Version of Record - Sep 19, 2014 OnlineFirst Version of Record - Aug 4, 2014 What is This? 1 Philips Healthcare , Hong Kong, China 2 Department of Radiology, Zhujiang Hospital, Southern Medical University , Guangzhou, China Published by: - The clinical value of dynamic contrast-enhanced magnetic resonance imaging at 3.0T to detect prostate cancer Abstract Objective: To compare dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and T2-weighted imaging (T2WI) at 3.0T for detection of prostate cancer. Methods: Patients with elevated prostate-specific antigen underwent T2WI and DCE-MRI prior to prostate needle biopsy. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of T2WI and DCE-MRI to diagnose prostate cancer were evaluated. The relationship between Gleason score and prostate cancer detection by DCE-MRI was evaluated. Results: Prostate adenocarcinoma was histopathologically confirmed in 44/75 patients. DCE-MRI had significantly higher sensitivity, accuracy and NPV than T2WI. The detection rate of prostate cancer by DCE-MRI was significantly better for tumours with Gleason score 79 than for those Gleason score 46. Conclusion: DCE-MRI at 3.0T can significantly improve prostate cancer detection using simple visual diagnostic criteria, compared with T2WI. Journal of International Medical Research 2014, Vol. 42(5) 10771084 ! The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0300060514541827 imr.sagepub.com Introduction Prostate cancer is the most common malignant tumour and the second most deadly cancer in men, in the developed world.1 Diagnosis of prostate cancer is based on digital rectal examination, serum concentration of prostate-specific antigen (PSA), Creative Commons CC-BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use, reproduction and distribution of the work without further permDioswsinolonadperdovfriodmedimtrh.seagoerpiugbin.caolmwboyrgkuiesstaottnriObcutotebdera1s6,s2p0e1c4ified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm). transrectal ultrasound-guided (TRUS) biopsy and magnetic resonance imaging (MRI). MRI has been widely used to aid prostate cancer detection and tumour staging. T2-weighted imaging (T2WI), in which tumour tissue appears hypointense relative to the normal peripheral tissue,2 has been used for morphological prostate tumour detection and localization, but the specificity of T2WI is low because benign prostatic hyperplasia, prostatitis, fibrosis and postbiopsy haemorrhage also cause T2 hypointensities.35 In addition, some prostate tumours appear normal on T2WI, leading to low sensitivity of this method.6,7 Functional MR techniques (such as dynamic contrast-enhanced MRI [DCE-MRI], diffusion-weighted imaging [DWI], and magnetic resonance spectroscopy [MRS]) have been used to increase the diagnostic accuracy of MR in prostate cancer.810 Dynamic contrast-enhanced MRI is useful in imaging tumour vascularization, vascular permeability and perfusion.11 The method involves intravascular injection of contrast agents and imaging of their concentrations in blood and tissue over time.11 Analysing contrast agent uptake in tissues usually involves the generation of a semiquantitative signal intensity/time curve or more complicated quantitative approaches using pharmacokinetic models. The highly specialized and time-consuming nature of these analyses likely prevents widespread clinical implementation of these methods,12,13 and, since they are nonstandardized, often generate unclear results.1417 Studies have focused on the analysis of raw DCE T1-weighted images (T1WI), which can be more easily implemented in daily clinical practice, compared with other imaging modalities.1823 These studies had low temporal resolution, minimal dynamic series and an acquisition time that was too brief to allow prostate cancer detection or comprehensive measurement of tumour haemodynamics. The aims of the present study, therefore, were to evaluate the clinical value of 3.0T DCE-MRI in detecting prostate cancer, and to compare imaging results with TRUSguided biopsy findings. Patients and methods Study population The study recruited consecutive male patients with elevated PSA (>4.0 ng/ml) and/or prostate nodule detected during digital rectal examination who attended the Department of Radiology, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China, for diagnosis between January 2012 and July 2013. Patients were required to have undergone both MRI and a subsequent transrectal prostate biopsy, and to not have received any treatment for prostate cancer. The study was approved by the ethics committee of the Zhujiang Hospital of Southern Medical University, Guangzhou, China. Written informed consent was obtained from all patients prior to enrolment. All MRI examinations were performed on a 3.0T whole-body multitransmit scanner system (Achieva TX, Philips Healthcare, Best, The Netherlands) using a 16-channel SENSE XL torso coil. T2-weighed, turbo spin-echo images with spectrally selective attenuated inversion recovery were obtained in the axial and coronal planes (repetition time [TR] 1483 ms; echo time [TE] 70 ms; slice thickness 5 mm; interslice gap 1 mm; number of slices 20; field of view [FOV] 240 240 mm; matrix size 256 256 pixels). DCE-MRI was performed using a threedimensional (3D) T1-fast field-echo (FFE) sequence in the axial plane (TR 5.5 ms; TE 1.7 ms, slice thickness 6 mm [reconstructed to 3 mm]; interslice gap 0 mm; FOV 230 230 mm; flip angle 15 ; matrix size 256 256 pixels). DCE-MRI images were scanned from the apex to the base of the prostate and a total of 20 slices were obtained. A 20-slice volume was obtained every 2.9 s and imaging comprised eight precontrast volumes and 96 postcontrast volumes. Postcontrast imaging was initiated immediately after administering 0.1 mmol/ kg body weight gadopentetate dimeglumine (Magnevist , Bayer Schering Pharma, Germany) at 2.5 ml/s via the cephalic vein. Contrast agent injections were followed by a 15-ml saline flush. The DCE-MRI examination time was 5 min and 6 s. Postimaging prostate biopsy Within 2 weeks of MRI, all patients underwent an extended 12- to 18-core TRUSguided biopsy. All samples were obtained from the peripheral zone bilaterally, including the base, mid-gland, apex, and the bilateral transitional zone. Each sample was histologically analysed by the same pathologist with 15 years genitourinary experience, and was determined to be cancerous or noncancerous according to the pathology. The T2WI and DCE-MRI data were prospectively analysed by two rad (...truncated)