PI-RADS version 2 accurately identifies clinically important prostate cancers in transition zone
Higher PI-RADS version 2 scores are associated with detecting more clinically important cancers in the transition zone (TZ), according to a new study published in Radiology.
The authors studied data from more than 600 TZ lesions in more than 450 patients who underwent multiparametric (MP) MRI of the prostate and transrectal ultrasound-guided biopsy between January 2012 and February 2015. Two genitourinary radiology fellows evaluated all detected and biopsied TZ lesions using PI-RADS version 2 scoring.
Overall, for PI-RADS category 2 TZ lesions, the overall proportion of cancers was 4 percent and no clinically important cancers were identified. For PI-RADS category 3, 4 and 5 lesions, the overall proportion of cancers was more than 22 percent, more than 39 percent and more than 87 percent, respectively. For PI-RADS category 3, 4 and 5 lesions, the proportion of clinically important cancers was more than 11 percent, more than 29 percent and more than 77 percent, respectively.
The authors noted a sensitivity of 68.5 percent, a specificity of more than 77 percent and a positive predictive value of more than 66 percent for overall cancer detection when using PI-RADS version 2 scoring to identify prostate cancers in the TZ. In addition, they reported a sensitivity of more than 78 percent, a specificity of more than 75 percent and a positive predictive value of more than 56 percent for detecting clinically important cancers.
“An interesting finding is that specificity and positive predictive value are higher for overall cancer detection than for detection of clinically important cancer,” wrote lead author Janice N. Thai, MD, center for interventional oncology at the National Cancer Institute and Clinical Center in Bethesda, Maryland, and colleagues. “This occurs because clinically important cancer is a subset of overall cancer; thus, there will be some positive test results for low-grade cancer in the overall cancer category that will contribute to the predictive value of overall cancer but not to the predictive value of clinically important cancer.”
Overall, Thai and colleagues concluded, PI-RADS version 2 scoring and prostate MP MRI “can be used to reliably detect clinically important cancers in the transition zone with high diagnostic accuracy.”
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.