ISSN 1305-3825 | E-ISSN 1305-3612
Modality-based (US, CT, MRI, PET-CT) Imaging - Original Article
Multiparametric MRI for the detection of local recurrence of prostate cancer in the setting of biochemical recurrence after low dose rate brachytherapy
1 Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Maryland, USA  
2 Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Maryland, USA  
3 Biometric Research Program, National Cancer Institute, National Institutes of Health, Maryland, USA  
4 Department of Radiology, University of Cambridge School of Clinical Medicine, Cambridge, UK  
5 Department of Diagnostic Radiology, Singapore General Hospital, Singapore  
6 Department of Radiology, Center for Biomedical Imaging, NYU School of Medicine, New York, USA  
7 Department of Radiology, Urology and Nephrology Center, Mansoura University, Mansoura City, Egypt  
8 Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Maryland, USA  
9 Orange Country Urology Associates, Laguna Hills, USA  
10 Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Maryland, USA  
11 Center for Interventional Oncology, National Cancer Institute, National Institutes of Health, Maryland, USA  
Diagn Interv Radiol ; : -

Abstract

Purpose: Prostate multi-parametric magnetic resonance imaging (mpMRI) has utility in detecting post-radiotherapy local recurrence. We conducted a multi-reader study to evaluate the diagnostic performance of mpMRI for local recurrence after low dose rate (LDR) brachytherapy.

 

Methods: 19 patients with biochemical recurrence after LDR brachytherapy underwent 3T endorectal coil mpMRI with T2-weighted imaging (T2WI), dynamic contrast enhancement (DCE) imaging, diffusion-weighted imaging (DWI) with pathologic confirmation. Prospective reads by an experienced prostate radiologist were compared to reads from 4 radiologists of varying experience. Readers identified suspicious lesions and rated each MRI detection parameter. MRI-detected lesions were considered true-positive with ipsilateral pathologic confirmation. Inferences for sensitivity, specificity, positive predictive value (PPV), kappa, and index of specific agreement (ISA) were made with the use of bootstrap resampling.

 

Results: 15/19 patients had pathologically confirmed recurrence. mpMRI-identified true positive recurrences were frequently located in the transition zone (46.7.0%) and seminal vesicles (30.0%). On patient-based analysis, average sensitivity of mpMRI was 88.0% (SE 3.5%). For highly suspicious lesions, specificity of mpMRI was 75.0% (SE 16.5%). On lesion-based analysis, the average PPV was 62.0% (SE 6.7%) for all lesions and 78.7% (SE 10.3%) for highly suspicious lesions. The average PPV for lesions invading the seminal vesicles was 88.8% (n=13). The average PPV was 66.6% (SE 5.8%) for lesions identified with T2WI, 64.9% (SE 7.3%) for DCE, and 70.0% (SE 7.3%) for DWI.

 

Conclusion: This series provides evidence that mpMRI after LDR brachytherapy is feasible with a high patient-based cancer detection rate. Radiologists of varying experience demonstrated moderate agreement in detecting recurrence.

Key Words
Authors
All
Author's Corner
Reviewer's Corner
Survey
Copyright © Turkish Society of Radiology | Latest Update: 01.11.2017