Article of the week: Likert vs PI‐RADS v2: a comparison of two radiological scoring systems for detection of clinically significant PCa
Every week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.
In addition to the article itself, there is an editorial written by a prominent member of the urological community and a video prepared by the authors; we invite you to use the comment tools at the bottom of each post to join the conversation.
If you only have time to read one article this week, we recommend this one.
Likert vs PI‐RADS v2: a comparison of two radiological scoring systems for detection of clinically significant prostate cancer
Christopher C. Khoo*†, David Eldred-Evans*†, Max Peters‡, Mariana Bertoncelli Tanaka*†, Mohamed Noureldin*†, Saiful Miah*†, Taimur Shah*†, Martin J. Connor*, Deepika Reddy*, Martin Clark§, Amish Lakhani§, Andrea Rockall§, Feargus Hosking-Jervis*, Emma Cullen*, Manit Arya*†, David Hrouda†, Hasan Qazi¶, Mathias Winkler*†, Henry Tam§ and Hashim U. Ahmed*†
*Imperial Prostate, Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, †Imperial Urology, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK, ‡Department of Radiotherapy, University Medical Centre, Utrecht, The Netherlands, §Department of Radiology, Charing Cross Hospital, Imperial College Healthcare NHS Trust and ¶Department of Urology, St. George’s Hospital, St. George’s Healthcare NHS Trust, London, UK
Abstract
Objective
To compare the clinical validity and utility of Likert assessment and the Prostate Imaging Reporting and Data System (PI‐RADS) v2 in the detection of clinically significant and insignificant prostate cancer.
Patients and Methods
A total of 489 pre‐biopsy multiparametric magnetic resonance imaging (mpMRI) scans in consecutive patients were subject to prospective paired reporting using both Likert and PI‐RADS v2 by expert uro‐radiologists. Patients were offered biopsy for any Likert or PI‐RADS score ≥4 or a score of 3 with PSA density ≥0.12 ng/mL/mL. Utility was evaluated in terms of proportion biopsied, and proportion of clinically significant and insignificant cancer detected (both overall and on a ‘per score’ basis). In those patients biopsied, the overall accuracy of each system was assessed by calculating total and partial area under the receiver‐operating characteristic (ROC) curves. The primary threshold of significance was Gleason ≥3 + 4. Secondary thresholds of Gleason ≥4 + 3, Ahmed/UCL1 (Gleason ≥4 + 3 or maximum cancer core length [CCL] ≥6 or total CCL≥6) and Ahmed/UCL2 (Gleason ≥3 + 4 or maximum CCL ≥4 or total CCL ≥6) were also used.
Table 1: Comparison of Likert and Prostate Imaging Reporting and Data System scoring.
Results
The median (interquartile range [IQR]) age was 66 (60–72) years and the median (IQR) prostate‐specific antigen level was 7 (5–10) ng/mL. A similar proportion of men met the biopsy threshold and underwent biopsy in both groups (83.8% [Likert] vs 84.8% [PI‐RADS v2]; P = 0.704). The Likert system predicted more clinically significant cancers than PI‐RADS across all disease thresholds. Rates of insignificant cancers were comparable in each group. ROC analysis of biopsied patients showed that, although both scoring systems performed well as predictors of significant cancer, Likert scoring was superior to PI‐RADS v2, exhibiting higher total and partial areas under the ROC curve.
Conclusions
Both scoring systems demonstrated good diagnostic performance, with similar rates of decision to biopsy. Overall, Likert was superior by all definitions of clinically significant prostate cancer. It has the advantages of being flexible, intuitive and allowing inclusion of clinical data. However, its use should only be considered once radiologists have developed sufficient experience in reporting prostate mpMRI.
