Evaluation of the Prostate Imaging Reporting and Data System for Magnetic Resonance Imaging Diagnosis of Prostate Cancer in Patients with Prostate-specific Antigen <20 ng/ml.
BACKGROUND
The European Society of Urogenital Radiology has built the Prostate Imaging Reporting and Data System (PI-RADS) for standardizing the diagnosis of prostate cancer (PCa). This study evaluated the PI-RADS diagnosis method in patients with prostate-specific antigen (PSA) <20 ng/ml.


METHODS
A total of 133 patients with PSA <20 ng/ml were prospectively recruited. T2-weighted (T2WI) and diffusion-weighted (DWI) magnetic resonance images of the prostate were acquired before a 12-core transrectal prostate biopsy. Each patient's peripheral zone was divided into six regions on the images; each region corresponded to two of the 12 biopsy cores. T2WI, DWI, and T2WI + DWI scores were computed according to PI-RADS. The diagnostic accuracy of the PI-RADS score was evaluated using histopathology of prostate biopsies as the reference standard.


RESULTS
PCa was histologically diagnosed in 169 (21.2%) regions. Increased PI-RADS score correlated positively with increased cancer detection rate. The cancer detection rate for scores 1 to 5 was 2.8%, 15.0%, 34.6%, 52.6%, and 88.9%, respectively, using T2WI and 12.0%, 20.2%, 48.0%, 85.7%, and 93.3%, respectively, using DWI. For T2WI + DWI, the cancer detection rate was 1.5% (score 2), 13.5% (scores 3-4), 41.3% (scores 5-6), 75.9% (scores 7-8), and 92.3% (scores 9-10). The area under the curve for cancer detection was 0.700 (T2WI), 0.735 (DWI) and 0.749 (T2WI + DWI). The sensitivity and specificity were 53.8% and 89.2%, respectively, when using scores 5-6 as the cutoff value for T2WI + DWI.


CONCLUSIONS
The PI-RADS score correlates with the PCa detection rate in patients with PSA <20 ng/ml. The summed score of T2WI + DWI has the highest accuracy in detection of PCa. However, the sensitivity should be further improved.
Department of Urology, Beijing Hospital, Beijing 100730, China.
Xuan
X
Wang
Department of Urology, Beijing Hospital, Beijing 100730, China.
Jian-Ye
JY
Wang
Department of Radiology, Beijing Hospital, Beijing 100730, China.
Chun-Mei
CM
Li
Department of Urology, Beijing Hospital, Beijing 100730, China.
Ya-Qun
YQ
Zhang
Department of Urology, Beijing Hospital, Beijing 100730, China.
Jian-Long
JL
Wang
Department of Urology, Beijing Hospital, Beijing 100730, China.
Ben
B
Wan
Department of Pathology, Beijing Hospital, Beijing 100730, China.
Wei
W
Zhang
Department of Radiology, Beijing Hospital, Beijing 100730, China.
Min
M
Chen
Department of Radiology, Beijing Hospital, Beijing 100730, China.
Sa-Ying
SY
Li
Department of Medical Statistics, Beijing Ditan Hospital, Beijing 100015, China.
Gang
G
Wan
Department of Urology, Beijing Hospital, Beijing 100730, China.
Ming
M
Liu
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis*
D017430:Prostate-Specific Antigen