Assessment of images and histopathological correlation
MpMRI images were evaluated before biopsy according to the PI-RADSv2.1
guidelines by two radiologists with 25-years of experience(reader-1) and
2-year of experience(reader-2) in abdominal MRI. The appearance,
localization, and dimensions of lesions were first independently
assessed by the two radiologists. Lesion localization was defined
according to the sector map in the PI-RADSv2.1 guidelines. Lesions
exceeding zonal anatomy (both PZ and transitional zone(TZ) spread) or
lesions with extraprostatic extension were defined as diffuse cancer.
Lesions were scored according to PI-RADSv2.1 criteria on T2 weighted
images(T2W) and diffusion weighted imaging(DWI). DCE-MRI was defined as
‘negative’ or ‘positive’ and each lesion was given a
PI-RADSv2.1(category 1-5) score. These scores were recorded to evaluate
the interobserver agreement. Due to the different PI-RADS scores in
between the readers, the final PI-RADS categorization was performed by
consensus for 28 lesions(Table-2).
Interobserver agreement of these variables and histopathological
correlation with PI-RADSv2.1 score were evaluated. Negative MpMRI
findings were assigned to PI-RADS-1.
Based on MpMRI findings and clinical suspicion of prostate cancer, a
biopsy was performed on the patients. While MpMRI cognitive fusion
TRUS-bx was applying with the 18G automatic tru-cut biopsy needle, the
hypoechogenic-hyperechogenic foci were considered, 2 samples were taken
from each lesion by correlating them with the foci defined in MpMRI and
marked on the sector map7. In addition to cognitive
fusion, 12-core systematic bx was performed. The TRUS-bx procedure was
performed by one of 3 experienced urologists. A total of 84 patients
diagnosed with using TRUS-guided CF-Bx had 106 lesions identified.
Biopsy specimens were evaluated by a urogenital pathologist. Malignant
lesions were grouped according to the ISUP scoring (ISUP1, GS3+3; ISUP2,
GS3+4; ISUP3, GS4+3; ISUP4, GS4+4; ISUP5, GS≥9)10. On
MpMRI, lesions that have PI-RADSv2.1 score ≥3 were recorded as positive,
while lesions have <3 score were recorded as negative lesions.