MRI/US-fusion-guided biopsy upgrades and detects PCa of higher Gleason score in 32% of patients compared with traditional 12-core biopsy alone. Targeted biopsy technique preferentially detects higher-grade PCa while missing lower-grade tumors.

The inclusion of MRI-derived parameters in a risk model could reduce the number of unnecessary biopsies while maintaining a high rate of diagnosis of clinically significant prostate cancers.

BACKGROUND: Active surveillance (AS) is an attempt to avoid overtreatment of clinically insignificant prostate cancer (PCa); however, patient selection remains controversial. Multiparametric prostate magnetic resonance imaging (MP-MRI) may help better select AS candidates. METHODS: We reviewed a cohort of men who underwent MP-MRI with MRI=Ultrasound fusion-guided prostate biopsy and selected potential AS patients at entry using Johns Hopkins criteria. MP-MRI findings were assessed, including number of lesions, dominant lesion diameter, total lesion volume, prostate volume, and lesion density (calculated as total lesion volume=prostate volume). Lesions were assigned a suspicion score for cancer by MRI. AS criteria were reapplied based on the confirmatory biopsy, and accuracy of MP-MRI in predicting AS candidacy was assessed. Logistic regression modeling and chi-square statistics were used to assess associations between MP-MRI interpretation and biopsy results. RESULTS: Eighty-five patients qualified for AS with a mean age of 60.2 years and mean prostate-specific antigen level of 4.8 ng=mL. Of these, 25 patients (29%) were reclassified as not meeting AS criteria based on confirmatory biopsy. Number of lesions, lesion density, and highest MRI lesion suspicion were significantly associated with confirmatory biopsy AS reclassification. These MRI-based factors were combined to create a nomogram that generates a probability for confirmed AS candidacy. CONCLUSION: As clinicians counsel patients with PCa, MP-MRI may contribute to the decision-making process when considering AS. Three MRI-based factors (number of lesions, lesion suspicion, and lesion density) were associated with confirmatory biopsy outcome and reclassification. A nomogram using these factors has promising predictive accuracy for which future validation is necessary.

Background Patients with negative TRUS biopsies yet persistently rising PSA values are at risk for occult but significant prostate cancers. The ability of multiparametric MRI and ultrasound (MRI/US) fusion biopsy to detect these occult prostate lesions may make it an effective tool in this challenging scenario. Methods Men with one or more negative systematic prostate biopsies participated in this trial. Between March 2007 and November 2011 all men underwent prostate 3T endorectal coil MRI and MRI/US fusion biopsy. In addition, all patients underwent standard 12 core TRUS biopsy in addition to targeted MRI/US fusion biopsy of concerning lesions identified on MRI. Results Of the 195 men with previous negative biopsies, 73 (37%) were found to have cancer using the MRI/US fusion platform combined with 12 core TRUS biopsy. High grade cancer (Gleason sum 8+) was discovered in 21 men (11%). All 21 men with high grade disease (100%) were detected with MRI/US fusion targeted biopsy while standard TRUS biopsy missed 12 of these high grade cancers (55%). Upgrading occurred in 28 men (38.9%) as a result of MRI targeting versus standard TRUS biopsy. The diagnostic yield of MRI with guided biopsy was unrelated to the number of previous negative biopsies, and persisted despite increasing number of previous biopsy sessions. On multivariable analysis, only PSAD and MRI suspicion level remained significant predictors of cancer. Conclusion Multiparametric MRI in conjunction with a MRI/US fusion biopsy platform is a novel diagnostic tool for detecting prostate cancer and may be ideally suited for patients with negative TRUS biopsies in the face of a persistent clinical suspicion for cancer.

ObjectivesTo determine the diagnostic yield of analysing biparametric (T2-and diffusion-weighted) magnetic resonance imaging (B-MRI) for prostate cancer detection compared with standard digital rectal examination (DRE) and prostate-specific antigen (PSA)-based screening. Patients and MethodsReview of patients who were enrolled in a trial to undergo multiparametric-prostate (MP)-MRI and MR/ultrasound fusion-guided prostate biopsy at our institution identified 143 men who underwent MP-MRI in addition to standard DRE and PSA-based prostate cancer screening before any prostate biopsy. Patient demographics, DRE staging, PSA level, PSA density (PSAD), and B-MRI findings were assessed for association with prostate cancer detection on biopsy. ResultsMen with detected prostate cancer tended to be older, with a higher PSA level, higher PSAD, and more screen-positive lesions (SPL) on B-MRI. B-MRI performed well for the detection of prostate cancer with an area under the curve (AUC) of 0.80 (compared with 0.66 and 0.74 for PSA level and PSAD, respectively). We derived combined PSA and MRI-based formulas for detection of prostate cancer with optimised thresholds. (i) for PSA and B-MRI: PSA level + 6 x (the number of SPL) > 14 and (ii) for PSAD and B-MRI: 14 × (PSAD) + (the number of SPL) >4.25. AUC for equations 1 and 2 were 0.83 and 0.87 and overall accuracy of prostate cancer detection was 79% in both models. ConclusionsThe number of lesions positive on B-MRI outperforms PSA alone in detection of prostate cancer. Furthermore, this imaging criteria coupled as an adjunct with PSA level and PSAD, provides even more accuracy in detecting clinically significant prostate cancer.

Background Prostate cancer is currently diagnosed by random biopsies resulting in the discovery of multiple low risk cancers that often lead to overtreatment. Multiparametric magnetic resonance imaging (mpMRI) may have the potential to identify patients at low risk for cancer, thus obviating the need for biopsy. Methods We reviewed 800 consecutive patients who underwent a 3 Tesla mpMRI of the prostate with endorectal coil from March 2007 to November 2011. Two radiologists independently reviewed all suspicious lesions using T2-weighted, diffusion weighted, spectroscopic, and dynamic contrast enhanced MRI sequences. Patients with only low suspicion lesions (maximum of two positive parameters on mpMRI) who subsequently underwent TRUS/MRI-fusion targeted biopsy were selected for analysis. Results One hundred and twenty-five patients with only low suspicion prostatic lesions on mpMRI were identified. On TRUS/MRI-fusion biopsy, 77 of these patients (62%) had no cancer detected, 38 patients had Gleason 6 disease, and 10 patients had Gleason 7 (3+4) disease. Thirty patients with cancer detected on biopsy qualified for active surveillance using 2011 NCCN guidelines. No cases of high risk (≥ Gleason 4+3) cancer were identified on biopsy and of the fifteen patients that underwent radical prostatectomy at our institution, none were pathologically upgraded to high risk cancer. Thus, for patients with only low suspicion lesions, 88% (107 patients) either had no cancer or clinically insignificant disease. Conclusion Our results demonstrate that low suspicion lesions on mpMRI are associated with either negative biopsies or low grade tumors suitable for active surveillance. Such patients have a low risk of harboring high risk prostate cancers.

Purpose Anteriorly located prostate cancer (PCa) is traditionally under-diagnosed using transrectal ultrasound (TRUS)-guided biopsy, although it represents a significant proportion of all PCa. We describe the detection rate of these tumors with the addition of MR/US fusion-guided biopsy (FGB) to standard TRUS-guided biopsy. Materials and Methods All patients regardless of their prior biopsy history who were referred for clinical suspicion of PCa (i.e elevated PSA and abnormal DRE) underwent 3T multiparametric-MRI (MP-MRI) screening; and those with suspicious lesions in the anterior region of the prostate were identified. Patients then received a FGB of all suspicious lesions in addition to systematic 12-core extended sextant TRUS-guided biopsy. We conducted a lesion based analysis comparing cancer detection rates of anterior targets using FGB versus systematic cores taken from the same anatomic sextant within the prostate. Lengths of cancer in the most involved core were also compared between the two biopsy techniques employed. Patients with only anterior targets were analyzed separately. Results Of 499 patients undergoing FGB, 162 patients had a total of 241 anterior lesions. Mean age, PSA, and prostate volume in this group was 62 years, 12.7ng/dl, and 57mL, respectively. In total, PCa was diagnosed in 121 (50.2%) of anterior lesions identified on MP-MRI. Sixty-two (25.7%) of these anterior lesions were documented positive for cancer on systematic 12-core TRUS-guided biopsy cores, while 97 (40.2%) were positive on the targeted FGB cores (p=0.001). In lesions that were positive on both FGB and TRUS biopsy, the most involved core was 112% longer on FGB (3.7mm vs. 1.6mm, p≤0.01). Forty-two patients had only anterior lesions on MP-MRI; twenty-four of them (57.1%) were found to have cancer on the FGB + TRUS biopsy platform. Six patients were positive on FGB only. Thirteen were positive on both modalities. However, 7 of 13 were upgraded by to a higher Gleason score by FGB. All 5 patients positive on TRUS biopsy only were active surveillance candidates. Conclusion FGB detects significantly more anteriorly located PCa than TRUS-guided biopsy alone and may serve to be an effective tool for this subset of patients.

No abstract