1444 WHAT BURDEN OF PROSTATE CANCER IS MISSED BY A NEGATIVE MULTI-PARAMETRIC MRI? AN ANALYSIS BASED ON TEMPLATE PROSTATE MAPPING AS THE REFERENCE STANDARD

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You have accessJournal of UrologyProstate Cancer: Detection and Screening II1 Apr 20121444 WHAT BURDEN OF PROSTATE CANCER IS MISSED BY A NEGATIVE MULTI-PARAMETRIC MRI? AN ANALYSIS BASED ON TEMPLATE PROSTATE MAPPING AS THE REFERENCE STANDARD Hashim Ahmed, Nimalan Arumainayagam, Alex Freeman, S. Aslam Sohaib, Alex Kirkham, Clare Allen, and Mark Emberton Hashim AhmedHashim Ahmed London, United Kingdom More articles by this author , Nimalan ArumainayagamNimalan Arumainayagam London, United Kingdom More articles by this author , Alex FreemanAlex Freeman London, United Kingdom More articles by this author , S. Aslam SohaibS. Aslam Sohaib London, United Kingdom More articles by this author , Alex KirkhamAlex Kirkham London, United Kingdom More articles by this author , Clare AllenClare Allen London, United Kingdom More articles by this author , and Mark EmbertonMark Emberton London, United Kingdom More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1938AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Much discussion has recently centred on the role of multi-parametric (mp)MRI in ruling-out clinically significant prostate cancer. Studies to date have set the target condition at various thresholds of ‘clinical significance': from ‘all cancer' or those lesions of volume >/=0.2cc or >/=0.5cc. The performance characteristics of mpMRI has a positive correlation with cancer volume, but there is uncertainty as to the disease burden that mpMRI misses when it is called ‘negative’or ‘normal2’. METHODS From 2006 to 2008, 64 men seeking reclassification of disease status (previous positive TRUS=51, no previous TRUS=3, previous negative TRUS=10) underwent mpMRI (1.5T, pelvic phased array, T2W, Diffusion, Dynamic Contrast) followed by Template Prostate Mapping (TPM). 3 radiologists independently reported scans blind to pathology using an ordinal scale of 1-5 (1=highly likely benign, 5=highly likely malignant) and 4 sectors per prostate (quadrants). The target condition to indicate a positive outcome on TPM was derived by varying the Maximum Cancer Core Length (MCCL) and Total Cancer Core Length (TCCL) thresholds from 1mm to 10mm. TCCL indicated the total amount of cancer from all positive cores in a sector of analysis. Sensitivity, specificity, negative and positive predictive values were calculated at each MCCL and TCCL threshold. The MCCL and TCCL values that gave rise to a negative predictive value (NPV) of >/=95% for mpMRI were derived. RESULTS Mean age was 62 years (range 40-76) and mean PSA 8.2ug/L (range 2.1–43). 54 men had cancer on TPM of which 18 had Gleason </=3+3. 127/256 (50%) sectors had cancer of which 83/127 (67%) had Gleason </=3+3. The sectors with no Gleason pattern 4 were used to derive endpoints for the purpose of this study, as this excluded the strong confounding variable of Gleason grade. Using a radiological score of >/=3, the MCCL and TCCL values that gave rise to a NPV of 95% for mpMRI were 4-6mm and 4-8mm, respectively. Using a radiological score of >/=4, the MCCL and TCCL values that gave rise to a NPV of 95% for mpMRI were 5-7mm and 6-10mm, respectively. If the MCCL values we have derived are used as diameters for a perfect sphere, then lesion volumes would be 0.03ml to 0.18ml. The NPV cancer with Gleason >/=3+4 was 90-95%, regardless of MCCL/TCCL. CONCLUSIONS If a prostate is deemed ‘negative’ on mpMRI, the maximum amount of prostate cancer that can still be present is 0.18ml and Gleason 3+3. mpMRI seems to have the ideal attributes of a triage diagnostic test to identify those men that could be advised to avoid a prostate biopsy. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e586 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hashim Ahmed London, United Kingdom More articles by this author Nimalan Arumainayagam London, United Kingdom More articles by this author Alex Freeman London, United Kingdom More articles by this author S. Aslam Sohaib London, United Kingdom More articles by this author Alex Kirkham London, United Kingdom More articles by this author Clare Allen London, United Kingdom More articles by this author Mark Emberton London, United Kingdom More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...