Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy

Abstract

We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.

The role of magnetic resonance imaging in the diagnosis and management of prostate cancer

“…In the transitional and anterior zones, the baseline T2 signal is lower and focal hypo-intense nodules caused by BPH are common; this reduced the detection accuracy of T2WI for cancer in these zones. T2WI alone is estimated to have a sensitivity of 48-88%, specificity of 44-81% and Area Under the Receiver Operating Curve (AUC-ROC) of 0.68-0.81 compared to radical prostatectomy [17][18][19][20][21]. The wide variation in these accuracy estimates is in part due to exclusion of transitional/ anterior cancers and insignificant cancers from the analysis in some studies.…”

Prostate cancer - the role of magnetic resonance imaging

“…Poor specificity and positive predictive value are less problematic since obtaining a few additional samples in false-positive areas do not seem to increase the number of biopsy morbidities 21 . MRI as a high-sensitivity high negative predictive value for guiding repeat biopsy towards aggressive cancer foci remains to be determined 22 . DCE-MRI imaging is a key technique for cancer detection with higher sensitivity than that of T2-weighted imaging.…”

“…Poor specificity is explained by the presence of a high incidence of inflammation on repeat biopsies. The use of endorectal coil might not be necessary when one is interested mainly in tumor detection and localization 8,22 . Since endorectal coils are expensive, this could have important practical consequences if MRI is to be used for routine screening in patients with elevated PSA and negative prostate biopsy.…”

“…However the combination DWI and DCE-MRI does not significantly improve the accuracy or sensitivity of DWI (ref. 22 ), but a combination of these methods in one examination are highly recommended.…”

Metabolomic Imaging for Human Prostate Cancer Detection using MR Spectroscopy at 7-T

“…In case of negative biopsies with elevated serum PSA, MRI is increasingly accepted to identify and localize PCa lesions, as well as for guidance of biopsy 25,26,27,28,29 .…”