Toshitaka Shin T, et al. – This study was carried out to assess the accuracy of MRI based Likert scoring system in detection of clinically significant prostate cancer (CSPC) using MRI/Ultrasonography (US) image–fusion targeted biopsy (FTB) as a reference standard. It was showed that the detection rates of overall cancer and CSPC strongly correlated with a 5–point grading of the Likert scale. There were significant differences in these cancer detection rates among the radiologists with different levels of experience.

Methods

• For this analysis, 1218 MRI–lesions were retrospectively reviewed in 629 patients who underwent subsequent MRI/US FTB between 10/2012 and 8/2015.
• Thereafter, 3–Tesla MRI was independently reported by 1 of 8 radiologists with varying levels of experience and scored on a 5–point Likert scale.
• They prospectively characterized all of lesions with Likert 1–5 as targets for MRI/US FTB.
• They characterized CSPC as Gleason score ≥7.

Results

• 64 years was the median patient age, PSA level was 6.97ng/ml and estimated prostate volume was 52.2ml.
• According to the data, of 1218 lesions, 48% (n=581) were rated as Likert 1–2, 35% (n=428) were Likert 3 and 17% (n=209) were Likert 4–5.
• Overall cancer detection rate were 12%, 13%, 22%, 50%, 59%, and CSPC detection rate were 4%, 4%, 12%, 33%, 48%, respectively according to the Likert system of grading from 1 to 5.
• They exhibited evidence that grading of a 5–point scale indicated strong positive association with overall cancer detection rate (r=0.949, p=0.05) and CSPC detection rate (r=0.944, p=0.05).
• In comparison between the more experienced radiologists for MRI–prostate and less experienced radiologists, they noted statistical differences in overall cancer detection rate (63% vs 35%, p=0.001) and CSPC detection rate (47% vs 29%, p=0.027) in Likert 4–5 lesions.