Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b
What’s known on the subject? and What does the study add?
Dynamic contrast enhanced (DCE) and diffusion weighted (DW) MRI have ...demonstrated their potential value in distinguishing malignant from benign prostate tissue, but none of them used alone is capable of optimally characterizing tumours in the prostate.
The combination of DW, DCE and T2W imaging increased significantly MRI performance for cancer detection in the peripheral zone.
OBJECTIVE
• To evaluate the combination of multiple magnetic resonance imaging (MRI) techniques, including T2‐weighted imaging (T2W), dynamic contrast‐enhanced imaging (DCE) and diffusion‐weighted imaging (DWI), for the detection and localization of prostate cancer.
PATIENTS AND METHODS
• In all, 57 patients underwent endorectal MRI at 1.5 T before radical prostatectomy (RP) for localized prostate cancer.
• On T2W images and histological whole‐mount analysis, the peripheral zone (PZ) and transition zone (TZ) were divided into upper and lower glands, as well as left and right halves, thus yielding four quadrants for each zone.
• On histological analysis, the total number of tumour foci, their location and larger diameter were recorded. T2W alone, T2W + DWI, T2W + DCE and all three techniques combined were scored for the likelihood of tumour in each area and results were compared with whole‐mount analysis.
• The area under the receiver operating characteristic curve (Az) was used to evaluate accuracy for tumour detection. The association between MR accuracy and Gleason score was statistically assessed.
RESULTS
• Of the 456 prostate octants analysed, 145 showed cancer on whole‐mount analysis, 120 (83%) of them with a diameter assumed to correspond to a volume >0.2 cm3. Gleason score was ≥7 in 68 (47%) tumours.
• In the PZ, the Az value was significantly higher for T2W + DWI, T2W + DCE and all three techniques combined than for T2W alone (P < 0.05).
• In the TZ, the Az value was higher for T2W + DWI than for T2W alone, but the difference was not significant.
• The Az value for T2W + DWI was significantly higher than that for T2W + DCE or for the three sequences combined.
• Gleason score was significantly associated with cancer detection in the PZ.
CONCLUSIONS
• Adding DWI and DCE to T2W imaging increased MRI performance in cancer detection in the PZ significantly.
• However, this multiparametric model failed to improve performance in the TZ.
• Gleason score significantly influenced cancer detection in the PZ but not in the TZ.
Whether multiparametric MRI improves the detection of clinically significant prostate cancer and avoids the need for systematic biopsy in biopsy-naive patients remains controversial. We aimed to ...investigate whether using this approach before biopsy would improve detection of clinically significant prostate cancer in biopsy-naive patients.
In this prospective, multicentre, paired diagnostic study, done at 16 centres in France, we enrolled patients aged 18–75 years with prostate-specific antigen concentrations of 20 ng/mL or less, and with stage T2c or lower prostate cancer. Eligible patients had been referred for prostate multiparametric MRI before a first set of prostate biopsies, with a planned interval of less than 3 months between MRI and biopsies. An operator masked to multiparametric MRI results did a systematic biopsy by obtaining 12 systematic cores and up to two cores targeting hypoechoic lesions. In the same patient, another operator targeted up to two lesions seen on MRI with a Likert score of 3 or higher (three cores per lesion) using targeted biopsy based on multiparametric MRI findings. Patients with negative multiparametric MRI (Likert score ≤2) had systematic biopsy only. The primary outcome was the detection of clinically significant prostate cancer of International Society of Urological Pathology grade group 2 or higher (csPCa-A), analysed in all patients who received both systematic and targeted biopsies and whose results from both were available for pathological central review, including patients who had protocol deviations. This study is registered with ClinicalTrials.gov, number NCT02485379, and is closed to new participants.
Between July 15, 2015, and Aug 11, 2016, we enrolled 275 patients. 24 (9%) were excluded from the analysis. 53 (21%) of 251 analysed patients had negative (Likert ≤2) multiparametric MRI. csPCa-A was detected in 94 (37%) of 251 patients. 13 (14%) of these 94 patients were diagnosed by systematic biopsy only, 19 (20%) by targeted biopsy only, and 62 (66%) by both techniques. Detection of csPCa-A by systematic biopsy (29·9%, 95% CI 24·3–36·0) and targeted biopsy (32·3%, 26·5–38·4) did not differ significantly (p=0·38). csPCa-A would have been missed in 5·2% (95% CI 2·8–8·7) of patients had systematic biopsy not been done, and in 7·6% (4·6–11·6) of patients had targeted biopsy not been done. Four grade 3 post-biopsy adverse events were reported (3 cases of prostatitis, and 1 case of urinary retention with haematuria).
There was no difference between systematic biopsy and targeted biopsy in the detection of ISUP grade group 2 or higher prostate cancer; however, this detection was improved by combining both techniques and both techniques showed substantial added value. Thus, obtaining a multiparametric MRI before biopsy in biopsy-naive patients can improve the detection of clinically significant prostate cancer but does not seem to avoid the need for systematic biopsy.
French National Cancer Institute.
Purpose We compared the accuracy of visual targeted biopsies vs computerized transrectal ultrasound-magnetic resonance imaging registration using a rigid (Esaote®, nondeformable) or elastic (Koelis®, ...deformable) approach. Materials and Methods A total of 391 consecutive patients with suspected localized prostate cancer were prospectively included in analysis. All patients underwent prostate magnetic resonance imaging, followed by 10 to 12-core random prostate biopsies. When magnetic resonance imaging detected suspicious findings, targeted biopsy was performed, including visual, rigid system and elastic system targeted biopsies in the first 127 patients, the next 131 and the last 133, respectively. Cancer detection rates were assessed by conditional logistic regression. Targeted biopsies alone and random biopsies were further compared for the amount of tissue sampled and microfocal cancer detection, the latter defined as a single core with 5 mm or less of Gleason 6 cancer. Results Patient characteristics and random biopsy detection rates were similar among the groups. Magnetic resonance imaging detected at least 1 suspicious area in 54 (42%), 78 (59%) and 82 patients (62%) in groups 1, 2 and 3, respectively. The cancer detection rates of rigid and elastic system targeted biopsies were significantly higher than the random biopsy rate (p = 0.0065 and 0.0016, respectively). Visual targeted biopsy did not perform better than random biopsy (p = 0.66). Rigid and elastic system targeted biopsies allowed for decreasing the number of cores and the detection of microfocal cancer, while increasing the detection of high grade cancer. Conclusions When performed with computerized magnetic resonance imaging-transrectal ultrasound image registration, targeted biopsy alone improved cancer detection over random biopsies, decreased the detection rate of microfocal cancer and increased the detection rate of cancer with a Gleason score of greater than 6.
Objectives
To evaluate the ability of high-frequency (29 MHz) transrectal micro-ultrasound (microUS) as a second-look examination after biparametric MRI (bp-MRI) and to reidentify focal lesions seen ...on diagnostic MRI and to detect new ones
Methods
A total of 118 consecutive men (mean age, 66 ± 13 SD years; range, 49–93 years) with a mean prostate-specific antigen level of 11 ± 19 (SD) ng/mL (range, 2–200 ng/mL) and at least one focal lesion (MRI+) with a score > 2 on bp-MRI were included. Of these, 79/118 (66.9%) were biopsy-naïve and 102/118 (86.5%) had non-suspicious rectal examination. All patients had MRI-directed microUS-guided biopsy using a 29-MHz transducer. All lesions visible on micro-ultrasound (microUS+) were targeted without image fusion, which was only used for MRI+/microUS− lesions. Significant prostate cancer (sPCa) was defined by a Gleason score ≥ 7 or a maximum cancer core length > 3 mm.
Results
A total of 144 focal prostatic lesions were analyzed, including 114 (114/144, 79.2%) MRI+/microUS+ lesions, 13 MRI+/microUS− lesions (13/144, 9%), and 17 MRI−/microUS+ lesions (17/144, 11.8%). Significant PCa was detected in 70 MRI+/microUS+ lesions (70/114, 61.4%), in no MRI+/microUS− lesion (0/13, 0%), and in 4 MRI-/microUS+ lesions (4/17, 23.5%). The sensitivity and specificity of microUS on a per-patient and a per-lesion basis were 100% (95% CI, 84.9–100%) and 22.8% (95% CI, 12.5–35.8%) and 100% (95% CI, 85.1–100%) and 22.6% (95% CI, 12.3–36.2%), respectively.
Conclusion
MicroUS, as a second-look examination, may show promise to localize targets detected on bp-MRI.
Key Points
• Used as a second-look examination, microUS-guided biopsies have a 100% detection rate of sCa originating in the PZ or lower third of the TZ, without microUS-MRI image fusion
.
• MicroUS results may provide additional information about lesions visible on MRI.
• MicroUS may provide the ability to detect small PZ lesions undetected by bp-MRI.
High-quality evidence shows that MRI in biopsy-naive men can reduce the number of men who need prostate biopsy and can reduce the number of diagnoses of clinically insignificant cancers that are ...unlikely to cause harm. In men with prior negative biopsy results who remain under persistent suspicion, MRI improves the detection and localization of life-threatening prostate cancer with greater clinical utility than the current standard of care, systematic transrectal US-guided biopsy. Systematic analyses show that MRI-directed biopsy increases the effectiveness of the prostate cancer diagnosis pathway. The incorporation of MRI-directed pathways into clinical care guidelines in prostate cancer detection has begun. The widespread adoption of the Prostate Imaging Reporting and Data System (PI-RADS) for multiparametric MRI data acquisition, interpretation, and reporting has promoted these changes in practice. The PI-RADS MRI-directed biopsy pathway enables the delivery of key diagnostic benefits to men suspected of having cancer based on clinical suspicion. Herein, the PI-RADS Steering Committee discusses how the MRI pathway should be incorporated into routine clinical practice and the challenges in delivering the positive health impacts needed by men suspected of having clinically significant prostate cancer.
Abstract Background Wide variations in acquisition protocols and the lack of robust diagnostic criteria make magnetic resonance imaging (MRI) detection of prostate cancer (PCa) one of the most ...challenging fields in radiology and urology. Objective To validate the recently proposed European Society of Urogenital Radiology (ESUR) scoring system for multiparametric MRI (mpMRI) of the prostate. Design, setting, and participants An institutional review board–approved multicentric prospective study; 129 consecutive patients (1514 cores) referred for mpMRI after at least one set of negative biopsies. Intervention Transfer of mpMRI-suspicious areas on three-dimensional (3D) transrectal ultrasound images by 3D elastic surface registration; random systematic and targeted cores followed by core-by-core analysis of pathology and mpMRI characteristics of the core locations. The ESUR scores were assigned after the procedure on annotated Digital Imaging and Communications in Medicine archives. Outcome measurements and statistical analysis Relationships between ESUR scores and biopsy results were assessed by the Mann-Whitney U test. The Yates correction and Pearson χ2 tests evaluated the association between categorical variables. A teaching set was randomly drawn to construct the receiver operating characteristic curve of the ESUR score sum (ESUR-S). The threshold to recommend biopsy was obtained from the Youden J statistics and tested in the remaining validation set in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Results and limitations Higher T2-weighted, dynamic weighted imaging and dynamic contrast-enhanced ESUR scores were observed in areas yielding cancer-positive cores. The proportion of positive cores increased with the ESUR-S aggregated in five increments (ESUR-S 3–5: 2.9%; ESUR-S 6–8: 11.1%; ESUR-S 9–10: 38.2%; ESUR-S 11–12: 63.4%; and ESUR-S 13–15: 83.3%; p < 0.0001). A threshold of ESUR-S ≥9 exhibited the following characteristics: sensitivity: 73.5%; specificity: 81.5%; positive predictive value: 38.2%; negative predictive value: 95.2%; and accuracy: 80.4%. Although the study was not designed to compare repeat biopsy strategies, more targeted cores than random systematic cores were found to be positive for cancer (36.3% compared with 4.9%, p < 0.00001). Conclusions In the challenging situation of repeat biopsies, the ESUR scoring system was shown to provide clinically relevant stratification of the risk of showing PCa in a given location.
The objective of our study was to analyze the feasibility and potential role of robotic-assisted transrectal MRI-guided biopsy for the diagnosis of prostate cancer.
A total of 57 patients (mean age, ...67 ± 6 SD years; age range, 57-83 years; mean prostate-specific antigen level, 10.7 ± 6.1 ng/mL) with a single prostatic lesion visible on biparametric MRI (T2-weighted and DW images) underwent robotic-assisted MRI-guided transrectal biopsy. The procedure was analyzed in terms of technical success, defined by an accurate alignment of the needle guide with the lesion; occupation time of the MRI room; number of cores; cancer detection rate (CDR); and complications.
The biparametric MRI score was 3, 4, and 5 in 11 (19%), 30 (53%), and 16 (28%) of the 57 patients, respectively. Twenty-three lesions (23/57, 40%) originated in the peripheral zone and 34 (34/57, 60%) in the transition zone. Software-based adjustments of the robot allowed the needle guide to be aligned with the target in all lesions. The number of cores was one, two, three, and four in one (2%), 36 (63%), 18 (32%), and three (5%) patients, respectively. Obtaining more than two cores had no incremental value in determining the Gleason score or the maximum cancer core length (MCCL). The overall CDR for any cancer was 67% (38/57). It was 95% (36/38) for tumors with Gleason grade of more than 3 or MCCL greater than 3 mm and 53% (20/38) for tumors with Gleason score greater than 6. No complications were observed. The median occupation time of the MRI room was 37.8 ± 9.7 minutes (range, 32-74 minutes).
Robotic-assisted MRI-guided biopsy yields 100% technical success rate with a short MRI room occupation time and high CDRs using one or two cores.
Objective
To prospectively determine the value of post-MRI micro-ultrasonography (microUS) in the diagnosis of transition zone (TZ) significant prostate cancer (sPCa).
Patients and methods
...Eighty-four consecutive men (66 ± 6.3 years) with a mean PSA level of 10.2 ± 7.4 ng/mL and at least one TZ-PI-RADS > 2 lesion were included. All patients had MRI-directed microUS and biopsy. Sensitivity and specificity of post-MRI microUS to visualize PI-RADS > 2 TZ lesions, the cancer detection rate of TZ-sPCa, and tumor characteristics according to their visibility on microUS were evaluated. Interreader agreement for detecting microUS+ lesions was evaluated using Cohen’s kappa test.
Results
Of the 92 PI-RADS > 2 lesions, 71 (71/92; 77%) were visible on microUS and biopsy was performed without image fusion, which was required for the 21 invisible lesions (21/92; 22.8%). TZ-sPCa detection rate was 51.1% (47/92). Sensitivity and specificity of MRI-directed microUS were 83% (39/47; 95% CI: 69.2–92.4%) and 28.9% (13/45; 95% CI: 16.4–44.3%), on a per-lesion basis and 86.4% (38/45; 95% CI: 72.6–94.8%) and 27.5% (11/40; 95% CI: 14.6–43.9%) on a per-patient basis. Visible tumors on microUS exhibited a larger volume and a lower mean ADC value than non-visible tumors (15.8 ± 5.1 vs. 12.5 ± 3.6 mm and 0.82 ± 1.1 × 10
3
vs. 0.9 ± 1.4 × 10
−3
mm
2
/s) (
p
= 0.02). Non-visible tumors showed a heterogeneous non-specific echotexture or were masked by the shadowing caused by corpora amylacea. Interreader agreement was almost perfect (kappa = 0.88; 95% CI: 0.79–0.95). The main limitation is the single-center feature of the study.
Conclusion
MRI-targeted transrectal microUS is effective to detect TZ-sPCa. TRUS-MRI image fusion helps overcome limitations due to TZ tissue heterogeneity.
Key Points
microUS can visualize the majority of MRI-detected PI-RADS > 2 TZ lesions (sensitivity = 83%).
Interreader agreement of MRI-directed microUS in the detection of TZ lesions appears excellent (kappa = 0.88).
In 77% of PI-RADS > 2 TZ lesions, biopsy was performed under microUS visual control. MRI fusion system was only used to overcome limitations due to tissue heterogeneity of benign prostatic hyperplasia.
Purpose Magnetic resonance imaging-transrectal ultrasound fusion targeted prostate biopsies were suggested to detect significant cancer with more accuracy than systematic biopsies. In this study we ...evaluate the pathological characteristics of multiparametric magnetic resonance imaging detected and undetected tumor foci on radical prostatectomy specimens. Materials and Methods We selected 125 consecutive patients treated with radical prostatectomy for clinically localized prostate cancer diagnosed on magnetic resonance imaging-transrectal ultrasound targeted biopsy and/or systematic biopsy. On multiparametric magnetic resonance imaging each suspicious area was graded according to the PI-RADS score. On radical prostatectomy specimen, tumor foci with a Gleason score greater than 3+3 and/or tumor volume greater than 0.5 ml were considered significant. A correlation analysis between multiparametric magnetic resonance imaging and pathological findings was performed. Results Pathological analysis of radical prostatectomy specimens detected 230 tumor foci. Of these, 137 were considered significant (Gleason score greater than 3+3 in 112) and were observed in 111 (89%) glands. A total of 95 individual tumor foci, including 14 significant foci, were missed with multiparametric magnetic resonance imaging. All of them were located in glands where another focus was detected with multiparametric magnetic resonance imaging. An additional 9 individual tumor foci, including 7 significant, were detected on multiparametric magnetic resonance imaging but missed with targeted biopsy, resulting in 5 (4%) significant cancers undetected with magnetic resonance imaging-transrectal ultrasound fusion targeted biopsy. The magnetic resonance imaging target largest diameter was associated with high volume (greater than 0.5 cc) foci detection, while PI-RADS score and cancer involvement on targeted biopsy were associated with significant foci detection. Conclusions In these series of men with suspicious prostate multiparametric magnetic resonance imaging findings, magnetic resonance imaging-transrectal ultrasound fusion guided targeted biopsy alone strategy would have resulted in the under detection of only 4% significant cancers.
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