title: Accuracy of MRI/MRSI-based transrectal ultrasound biopsy in peripheral and transition zones of the prostate gland in patients with prior negative biopsy.
abstract: The purpose of the study was to evaluate the accuracy of transrectal ultrasound biopsy (TRUS-biopsy) performed on regions with abnormal MRI and/or MRSI for both the transition (TZ) and the peripheral (PZ) zones in patients with suspected prostate cancer with prior negative biopsy, and to analyze the relationship between MRSI and histopathological findings. MRI and MRSI were performed in 54 patients (mean age: 63.9 years, mean PSA value: 11.4 ng/mL) and the ability of MRI/MRSI-directed TRUS biopsy was evaluated. A three-point score system was used for both techniques to distinguish healthy from malignant regions. Descriptive statistics and ROC analyses were performed to evaluate the accuracy and the best cut-off in the three-point score system. Twenty-two out of 54 patients presented cancer at MRI/MRSI-directed TRUS biopsy, nine presented cancer only in PZ, eight both in PZ and TZ, and five exclusively in TZ. On a patient basis the highest accuracy was obtained by assigning malignancy on a positive finding with MRSI and MRI even though it was not significantly greater than that obtained using MRI alone (area under the ROC curve, AUC: 0.723 vs 0.676). On a regional (n = 648) basis the best accuracy was also obtained by considering positive both MRSI and MRI for PZ (0.768) and TZ (0.822). MRSI was false positive in 11.9% of the regions. Twenty-eight percent of cores with prostatitis were false positive findings on MRSI, whereas only 2.7% of benign prostatic hyperplasia was false positive. In conclusion, the accuracy of MRI/MRSI-directed biopsies in localization of prostate cancer is good in patient (0.723) and region analyses (0.768). The combination of both MRI and MRSI results makes TRUS-biopsy more accurate, particularly in the TZ (0.822) for patients with prior negative biopsies. Histopathological analysis showed that the main limitation of MRSI is the percentage of false positive findings due to prostatitis.
authors.affiliation: University of Bologna, Dipartimento di Medicina Interna, Bologna, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Testa
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiavina
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Salizzoni
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
authors.forename: Antonietta
authors.initials: A
authors.lastname: D'Errico
authors.forename: Barbara
authors.initials: B
authors.lastname: Corti
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Morselli-Labate
authors.forename: Alessandro
authors.initials: A
authors.lastname: Franceschelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bertaccini
authors.forename: Fabio
authors.initials: F
authors.lastname: Manferrarik
authors.forename: Walter Francesco
authors.initials: WF
authors.lastname: Grigioni
authors.forename: Romeo
authors.initials: R
authors.lastname: Canini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Martorana
authors.forename: Bruno
authors.initials: B
authors.lastname: Barbiroli
mesh_terms: D019540:Area Under Curve; D001706:Biopsy / Q000379:methods*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging* / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging / Q000473:pathology; D011472:Prostatitis / Q000000981:diagnostic imaging / Q000473:pathology; D012680:Sensitivity and Specificity; D014463:Ultrasonography