The accuracy of multiparametric MRI in men with negative biopsy and elevated PSA level--can it rule out clinically significant prostate cancer?

Evidence-based guideline recommendations on multiparametric magnetic resonance imaging in the diagnosis of prostate cancer: A Cancer Care Ontario clinical practice guideline

This clinical guideline focuses on: 1) the use of multiparametric magnetic resonance imaging (mpMRI) in diagnosing clinically significant prostate cancer (CSPC) in patients with an elevated risk of CSPC and who are biopsy-naïve; and 2) the use of mpMRI in diagnosing CSPC in patients with a persistently elevated risk of having CSPC and who have a negative transrectal ultrasound (TRUS)-guided systematic biopsy. The methods of the Practice Guideline Development Cycle were used. MEDLINE, EMBASE, the Cochrane Library (1997‒April 2014), main guideline websites, and relevant annual meeting abstracts (2011‒2014) were searched. Internal and external reviews were conducted. The two main recommendations are: Recommendation 1: In patients with an elevated risk of CSPC (according to prostate-specific antigen [PSA] levels and/or nomograms) who are biopsy-naïve: mpMRI followed by targeted biopsy (biopsy directed at cancer-suspicious foci detected with mpMRI) should not be considered the standard of care.Data from future research studies are essential and should receive high-impact trial funding to determine the value of mpMRI in this clinical context.Recommendation 2: In patients who had a prior negative TRUS-guided systematic biopsy and demonstrate an increasing risk of having CSPC since prior biopsy (e.g., continued rise in PSA and/or change in findings from digital rectal examination): mpMRI followed by targeted biopsy may be considered to help in detecting more CSPC patients compared with repeated TRUS-guided systematic biopsy.

Focal therapy in prostate cancer: A review of seven common controversies

Radical treatments such as prostatectomy and radiotherapy have demonstrated success in terms of biochemical and disease-specific survival for localised prostate cancer. However, whilst the end goal of any cancer treatment is to control or cure disease it must also do so by minimising any side effects that may be experienced by the patient. Focal therapy as a concept aims to redress this established therapeutic ratio by treating areas of the prostate affected by significant disease as opposed to treating the entire gland. However, there are a number of common criticisms of focal therapy - we deem the seven sins - that require further interrogation.

Role of multi-parametric MRI of the prostate for screening and staging: Experience with over 1500 cases

Objective

Contemporary prostate cancer (PCa) screening modalities such as prostate specific antigen (PSA) and digital rectal examination (DRE) are limited in their ability to predict the detection of clinically significant disease. Multi-parametric magnetic resonance imaging (mpMRI) of the prostate has been explored as a staging modality for PCa. Less is known regarding its utility as a primary screening modality. We examined our experience with mpMRI as both a screening and staging instrument.

Methods

mpMRI studies performed between 2012 and 2014 in patients without PCa were cross-referenced with transrectal ultrasonography (TRUS) biopsy findings. Statistical analyses were performed to determine association of mpMRI findings with overall cancer diagnoses and clinically significant (Gleason score ≥7) disease. Subgroup analyses were then performed on patients with a history of prior negative biopsy and those without a history of TRUS biopsy. mpMRI studies were also cross-referenced with RP specimens. Statistical analyses determined predictive ability of extracapsular extension (ECE), seminal vesicle involvement (SVI), and pathologic evidence of clinically significant disease (Gleason score ≥7).

Results

Four hundred biopsy naïve or prior negative biopsy patients had positive mpMRI studies. Overall sensitivity, specificity, positive and negative predictive values were 94%, 37%, 58%, and 87%, respectively and 95%, 31%, 42%, and 93%, respectively for overall cancer detection and Gleason score ≥7 disease. In patients with no prior biopsy history, mpMRI sensitivity, specificity, positive and negative predictive values were 94%, 36%, 65%, and 82%, for all cancers, and 95%, 30%, 50%, and 89% for Gleason score≥7 lesions, respectively. In those with prior negative biopsy sensitivity, specificity, positive and negative predictive values were 94%, 37%, 52%, and 90% for all cancers, and 96%, 32%, 36%, and 96% for Gleason score ≥7 lesions, respectively. Seventy-four patients underwent radical prostatectomy (RP) after mpMRI. Lesion size on mpMRI correlated with the presence of Gleason score ≥7 cancers (p = 0.005). mpMRI sensitivity, specificity, positive and negative predictive values were 84%, 39%, 81%, and 44% respectively, for Gleason ≥7 cancer. For ECE and SVI, sensitivity and specificity were 58% and 98% and 44% and 97%, respectively.

Conclusion

mpMRI is an accurate predictor of TRUS biopsy and RP outcomes. mpMRI has significant potential to change PCa management, particularly in the screening population, in whom a significant proportion may avoid TRUS biopsy. Further studies are necessary to determine how mpMRI should be incorporated into the current PCa screening and staging paradigms.

Assessing clinically significant prostate cancer: Diagnostic properties of multiparametric magnetic resonance imaging compared to three-dimensional transperineal template mapping histopathology

OBJECTIVE

To evaluate the diagnostic properties of multiparametric magnetic resonance imaging in the detection, localization and characterization of prostate cancer using three-dimensional transperineal template mapping biopsy histopathology as the comparator.

METHODS

A retrospective analysis of patients undergoing prostate multiparametric magnetic resonance imaging followed by three-dimensional transperineal template mapping biopsy was carried out. For imaging and pathology data, the prostate was divided in octants with the urethra being the midline. The index test properties were calculated using the biopsy histopathology as the reference test with the following end-points: any cancer, any Gleason ≥7, any Gleason ≥7 or cancer length of ≥4 mm and any Gleason ≥7 or 6 mm in any given core. The latter two definitions correspond to 0.2 and 0.5 mL of cancer volume, respectively. Diagnostic properties including sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

A total of 50 patients were included in the study. A median of 55 (interquartile range 42-63) biopsy cores were obtained per patient. Of 400 prostate octants evaluated, 28.5% had prostate cancer on mapping biopsy, whereas 23% of octants were considered suspicious for cancer on imaging. Multiparametric magnetic resonance imaging negative predictive values for Gleason ≥7 and clinically significant cancers were 84-100%. Similarly, specificity ranged between 79% and 85%. Sensitivity and positive predictive value remained moderate for all the reference test definitions.

CONCLUSIONS

Multiparametric magnetic resonance imaging is a useful minimally-invasive tool for detection, localization and characterization of prostate cancer. This imaging modality has high negative predictive value and specificity, and therefore it could be used to reliably rule out clinically significant cancer, obviating the multicore mapping biopsy.

Integration of multiparametric MRI into active surveillance of prostate cancer

Prostate cancer is the most common noncutaneous cancer in men though many men will not die of this disease and may not require definitive treatment. Active surveillance (AS) is an increasingly utilized potential solution to the issue of overtreatment of prostate cancer. Traditionally, prostate cancer patients have been stratified into risk groups based on clinical stage on digital rectal examination, prostate-specific antigen and biopsy Gleason score, though each of these variables has significant limitations. This review will discuss the potential role for prostate multiparametric MRI and targeted biopsy techniques incorporating MRI in the selection of candidates for AS, monitoring patients on AS and as triggers for definitive treatment.

Biparametric 3T Magnetic Resonance Imaging for prostatic cancer detection in a biopsy-naïve patient population: a further improvement of PI-RADS v2?

OBJECTIVES

To prospectively determine the diagnostic accuracy of a biparametric 3T magnetic resonance imaging protocol (BP-MRI) for prostatic cancer detection, compared to a multiparametric MRI protocol (MP-MRI), in a biopsy naïve patient population.

METHODS

Eighty-two untreated patients (mean age 65±7.6years) with clinical suspicion of prostate cancer and/or altered prostate-specific antigen (PSA) levels underwent a MP-MRI, including T2-weighted imaging, diffusion-weighted imaging (with the correspondent apparent diffusion coefficient maps) and dynamic contrast enhanced sequence, followed by prostate biopsy. Two radiologists reviewed both the BP-MRI and the MP-MRI protocols to establish a radiological diagnosis. Receiver operating characteristics curves were obtained to determine the diagnostic performance of the two protocols.

RESULTS

The mean PSA level was 8.8±8.1ng/ml. A total of 34 prostatic tumors were identified, with a Gleason score that ranged from 3+3 to 5+4. Of these 34 tumors, 29 were located within the peripheral zone and 5 in the transitional zone. BP-MRI and MP-MRI showed a similar performance in terms of overall diagnostic accuracy, with an area under the curve of 0.91 and 0.93, respectively (p=n.s.).

CONCLUSIONS

BP-MRI prostate protocol is feasible for prostatic cancer detection compared to a standard MP-MRI protocol, requiring a shorter acquisition and interpretation time, with comparable diagnostic accuracy to the conventional protocol, without the administration of gadolinium-based contrast agent.

Dynamic contrast-enhanced imaging has limited added value over T2-weighted imaging and diffusion-weighted imaging when using PI-RADSv2 for diagnosis of clinically significant prostate cancer in patients with elevated PSA

AIM

To determine the added value of dynamic contrast-enhanced imaging (DCE) over T2-weighted imaging (T2-WI) and diffusion-weighted imaging (DWI) for detection of clinically significant prostate cancer (csPC) in patients with elevated prostate-specific antigen (PSA).

METHODS AND MATERIALS

Two hundred and forty-five patients with elevated PSA underwent multiparametric (mp) magnetic resonance imaging (MRI) of the prostate before biopsy. mpMRI was performed using a 3 T MRI system without an endorectal coil. Patients underwent transrectal ultrasound-guided systematic 12 core biopsy followed by radical prostatectomy (n=68), radiation therapy (n=91), or clinical follow-up for at least 2 years (n=86). csPC was defined as Gleason score ≥3+4 and/or tumour volume of ≥0.5 ml, and/or tumour stage ≥T3a. The MRI findings were scored according to the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and an alternative overall assessment category (PI-RADSv2Alt) based on only T2-WI and DWI.

RESULTS

In 144 patients (58.8%), csPC was found within 2 years after MRI. With scoring according to the PI-RADSv2 guidelines, DCE was not needed for determination of the overall assessment category in 80.8% (198/245) of patients. Receiver operating characteristic (ROC) analysis showed an area under the curve of 0.79 (95% confidence interval [CI]: 0.74-0.85) for PI-RADSv2 and 0.79 (95% CI: 0.73-0.85) for PI-RADSv2Alt.

CONCLUSION

The added value of DCE over T2-WI and DWI is limited when using PI-RADSv2 for diagnosis of csPC in patients with elevated PSA before biopsy. An alternative overall assessment score using only T2-WI and DWI yielded similar performance to PI-RADSv2.

Magnetic Resonance Image-Guided Focal Prostate Ablation

Prostate cancer is the most common cancer (other than skin cancer) in American men, with one in seven men being diagnosed with this disease during his lifetime. The estimated number of new prostate cancer cases in 2016 is 180,890. For the first time, imaging has become the center of the search for contained, intraglandular, small-volume, and unifocal disease, and an increasing number of academic institutions as well as private practices are implementing programs for prostate multiplanar magnetic resonance imaging (MRI) as parts of their routine offerings. This article reviews the role of MRI-guided focal prostate ablation, as well as opportunities for further growth in this minimally invasive therapy of prostate cancer.

Risk stratification of prostate cancer utilizing apparent diffusion coefficient value and lesion volume on multiparametric MRI

PURPOSE

To evaluate the performance of apparent diffusion coefficient (ADC) and lesion volume in potentially risk-stratifying patients with prostate cancer (PCa).

MATERIALS AND METHODS

Men with elevated prostate-specific antigen or abnormal digital rectal exam underwent a 3T multiparametric magnetic resonance imaging (mpMRI) with endorectal coil. ADC maps were calculated using b values of 0, 500, 1000, and 1500; additional images were obtained with b value of 2000. We prospectively enrolled 312 men with lesions suspicious for cancer (suspicion score 2-5) on mpMRI. MRI/ultrasound fusion-guided prostate biopsies were performed. Mean ADC of suspicious lesions were correlated against lesion volume, Gleason and D'Amico risk.

RESULTS

The cancer detection rate of fusion biopsy per lesion was 45.6% (206/452). Cancerous lesions were larger (median volume: 0.40 vs. 0.30 cm³ ; P = 0.016). The median ADC (×10^-6 mm² /sec) for lesions negative and positive for PCa were 984.5 and 666.5, respectively (P < 0.0001). The AUC of ADC in predicting PCa was 0.79. Larger lesions were associated with higher risk PCa (Gleason and D'Amico) and lower ADC (all P < 0.0001).

CONCLUSION

The mean ADC of suspicious lesions on mpMRI was inversely correlated, while lesion volume had a direct correlation with PCa detection. Future follow-up studies are needed to assess longitudinal cancer risks of suspicious mpMRI lesions.

LEVEL OF EVIDENCE

2 J. Magn. Reson. Imaging 2017;45:610-616.

Assessment of the Performance of Magnetic Resonance Imaging/Ultrasound Fusion Guided Prostate Biopsy against a Combined Targeted Plus Systematic Biopsy Approach Using 24-Core Transperineal Template Saturation Mapping Prostate Biopsy

Objective. To compare the performance of multiparametric resonance imaging/ultrasound fusion targeted biopsy (MRI/US-TBx) to a combined biopsy strategy (MRI/US-TBx plus 24-core transperineal template saturation mapping biopsy (TTMB)). Methods. Between May 2012 and October 2015, all patients undergoing MRI/US-TBx at our institution were included for analysis. Patients underwent MRI/US-TBx of suspicious lesions detected on multiparametric MRI +/− simultaneous TTMB. Subgroup analysis was performed on patients undergoing simultaneous MRI/US-TBx + TTMB. Primary outcome was PCa detection. Significant PCa was defined as ≥Gleason score (GS) 3 + 4 = 7 PCa. McNemar's test was used to compare detection rates between MRI/US-TBx and the combined biopsy strategy. Results. 148 patients underwent MRI/US-TBx and 80 patients underwent MRI/US-TBx + TTMB. In the MRI/US-TBx versus combined biopsy strategy subgroup analysis (n = 80), there were 55 PCa and 38 significant PCa. The detection rate for the combined biopsy strategy versus MRI/US-TBx for significant PCa was 49% versus 40% (p = 0.02) and for insignificant PCa was 20% versus 10% (p = 0.04), respectively. Eleven cases (14%) of significant PCa were detected exclusively on MRI/US-TBx and 7 cases (8.7%) of significant PCa were detected exclusively on TTMB. Conclusions. A combined biopsy approach (MRI/US-TBx + TTMB) detects more significant PCa than MRI/US-TBx alone; however, it will double the detection rate of insignificant PCa.

Predictors of pathological upgrading in low-risk prostate cancer patients without hypointense lesions on an apparent diffusion coefficient map of multiparametric magnetic resonance imaging

PURPOSE

To examine the clinicopathological features and identify the predictors of pathological upgrading in low-risk prostate cancer (PCa) patients without hypointense lesions on the apparent diffusion coefficient (ADC) map calculated from multiparametric magnetic resonance imaging.

METHODS

We reviewed the medical records of 1905 PCa patients who underwent radical prostatectomy between 2007 and 2015. All ADC images were graded using the five-grade Likert scale; the positive hypointense lesions were graded 4-5. We analyzed 256 patients with low-risk classifications according to D'Amico criteria. Patients were classified into two groups according to the pathologic upgrading in the surgical specimens. The predictive factors for pathologic upgrading were evaluated using a multivariate logistic regression analysis.

RESULTS

In 256 patients with low-risk PCa, the percentage of positive cores [odds ratio (OR) 1.09; 95 % confidence interval (CI) 1.02-1.16], the percentage of cancer in the positive cores (OR 1.07, 95 % CI 1.03-1.12), and the presence of hypointensity on an ADC map (OR 2.28; 95 % CI 1.23-4.22) were independent predictors of pathologic upgrading. Notably, 138 of low-risk patients (53.9 %) had no hypointense lesions on an ADC map. Of these 138 patients, the percentage of positive cores (OR 1.09; 95 % CI 1.01-1.18) and the percentage of cancer in the positive cores (OR 1.06; 95 % CI 1.01-1.12) remained independent predictors of pathologic upgrading.

CONCLUSIONS

In low-risk PCa patients without hypointense lesions on an ADC map, biopsy-related parameters such as the percentage of positive cores and the percentage of cancer in the positive cores were independent predictors of pathological upgrading following radical prostatectomy.

Optimizing Patient Population for MP-MRI and Fusion Biopsy for Prostate Cancer Detection

The diagnosis and treatment of prostate cancer continue to evolve with advances in science and technology. The utilization of multiparametric MRI (mp-MRI) to identify lesions in the prostate has given clinicians the ability to visualize malignancy in the prostate with greater confidence. With this new ability came the advancement of fusion biopsy platforms, which allow for direct targeting of these lesions. As with any new technology in medicine, the proper use of these modalities and how they fit into current clinical practice need to be addressed. This review summarizes the current knowledge on how to best optimize which men undergo mp-MRI and fusion biopsies both in the screening and treatment settings.

Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41-1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others.

18F-Choline PET/MRI: The Additional Value of PET for MRI-Guided Transrectal Prostate Biopsies

We assessed the value of fusion (18)F-fluoromethylcholine ((18)F-choline) PET/MRI for image-guided (targeted) prostate biopsies to detect significant prostate cancer (Gleason ≥ 3 + 4) compared with standard (systematic 12-core) biopsies.

METHODS

Within an ongoing prospective clinical trial, hybrid (18)F-choline PET/CT and multiparametric 3T MRI (mpMRI) of the pelvis were performed in 36 subjects with a rising prostate-specific antigen for known (n = 15) or suspected (n = 21) prostate cancer before a prostate biopsy procedure. PET and T2-weighted MR volumes of the prostate were spatially registered using commercially available software. Biopsy targets were selected on the basis of visual appearance on MRI and graded as low, intermediate, or high risk for significant disease. Volumes of interest were defined for MR-identified lesions. (18)F-choline uptake measures were obtained from the MR target and a mirrored background volume of interest. The biopsy procedure was performed after registration of real-time transrectal ultrasound with T2-weighted MR and included image-guided cores plus standard cores. Histologic results were determined from standard and targeted biopsy cores as well as prostatectomy specimens (n = 10).

RESULTS

Fifteen subjects were ultimately identified with Gleason ≥ 3 + 4 prostate cancer, of which targeted biopsy identified significantly more (n = 12) than standard biopsies (n = 5; P = 0.002). A total of 52 lesions were identified by mpMRI (19 low, 18 intermediate, 15 high risk), and mpMRI-assigned risk was a strong predictor of final pathology (area under the curve = 0.81; P < 0.001). When the mean (18)F-choline target-to-background ratio was used, the addition of (18)F-choline to mpMRI significantly improved the prediction of Gleason ≥ 3 + 4 cancers over mpMRI alone (area under the curve = 0.92; P < 0.001).

CONCLUSION

Fusion PET/MRI transrectal ultrasound image registration for targeted prostate biopsies is clinically feasible and accurate. The addition of (18)F-choline PET to mpMRI improves the identification of significant prostate cancer.

Role of multiparametric magnetic resonance imaging in early detection of prostate cancer

Abstract

Most prostate cancers (PC) are currently found on the basis of an elevated PSA, although this biomarker has only moderate accuracy. Histological confirmation is traditionally obtained by random transrectal ultrasound guided biopsy, but this approach may underestimate PC. It is generally accepted that a clinically significant PC requires treatment, but in case of an non-significant PC, deferment of treatment and inclusion in an active surveillance program is a valid option. The implementation of multiparametric magnetic resonance imaging (mpMRI) into a screening program may reduce the risk of overdetection of non-significant PC and improve the early detection of clinically significant PC. A mpMRI consists of T2-weighted images supplemented with diffusion-weighted imaging, dynamic contrast enhanced imaging, and/or magnetic resonance spectroscopic imaging and is preferably performed and reported according to the uniform quality standards of the Prostate Imaging Reporting and Data System (PIRADS). International guidelines currently recommend mpMRI in patients with persistently rising PSA and previous negative biopsies, but mpMRI may also be used before first biopsy to improve the biopsy yield by targeting suspicious lesions or to assist in the selection of low-risk patients in whom consideration could be given for surveillance.

Teaching Points

• MpMRI may be used to detect or exclude significant prostate cancer.

• MpMRI can guide targeted rebiopsy in patients with previous negative biopsies.

• In patients with negative mpMRI consideration could be given for surveillance.

• MpMRI may add valuable information for the optimal treatment selection.

Prostate cancer detection with magnetic resonance-ultrasound fusion biopsy: The role of systematic and targeted biopsies

BACKGROUND

The current study was conducted to evaluate the performance of magnetic resonance (MR)-ultrasound-guided fusion biopsy in diagnosing clinically significant prostate cancer (csCaP).

METHODS

A total of 1042 men underwent multiparametric MR imaging (mpMRI) and fusion biopsy consecutively in a prospective trial (2009-2014). An expert reader graded mpMRI regions of interest (ROIs) as 1 to 5 using published protocols. The fusion biopsy device was used to obtain targeted cores from ROIs (when present) followed by a fusion image-guided, 12-core systematic biopsy in all men, even if no suspicious ROI was noted. The primary endpoint of the study was the detection of csCaP (ie, Gleason score ≥ 7).

RESULTS

Among 825 men with ≥ 1 suspicious ROI of ≥ grade 3, 289 (35%) were found to have csCaP. Powerful predictors of csCaP were ROI grade (grade 5 vs grade 3: odds ratio, 6.5 [P<.01]) and prostate-specific antigen density (each increase of 0.05 ng/mL/cc: odds ratio, 1.4 [P<.01]). Combining systematic and targeted biopsies resulted in the detection of more patients with csCaP (289 patients) than targeting (229 patients) or systematic (199 patients) biopsy alone. Among patients with no suspicious ROI, 35 (16%) were found to have csCaP on systematic biopsy.

CONCLUSIONS

In this prospective trial, MR-ultrasound fusion biopsy allowed for the detection of csCaP, with a direct relationship noted with ROI grade and prostate-specific antigen density. The combination of targeted and systematic biopsy detected more csCaP than either modality alone; systematic biopsies revealed csCaP in 16% of men with no suspicious MRI target. The advantages of this new biopsy method are apparent, but issues of cost, training, and reliability await resolution before its widespread adoption.

Recent advances in surgical planning & navigation for tumor biopsy and resection

This paper highlights recent advancements in imaging technologies for surgical planning and navigation in tumor biopsy and resection which need high-precision in detection and characterization of lesion margin in preoperative planning and intraoperative navigation. Multimodality image-guided surgery platforms brought great benefits in surgical planning and operation accuracy via registration of various data sets with information on morphology [X-ray, magnetic resonance (MR), computed tomography (CT)], function connectivity [functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), rest-status fMRI], or molecular activity [positron emission tomography (PET)]. These image-guided platforms provide a correspondence between the pre-operative surgical planning and intra-operative procedure. We envisage that the combination of advanced multimodal imaging, three-dimensional (3D) printing, and cloud computing will play increasingly important roles in planning and navigation of surgery for tumor biopsy and resection in the coming years.

Risk-based Patient Selection for Magnetic Resonance Imaging-targeted Prostate Biopsy after Negative Transrectal Ultrasound-guided Random Biopsy Avoids Unnecessary Magnetic Resonance Imaging Scans

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) is increasingly used in men with suspicion of prostate cancer (PCa) after negative transrectal ultrasound (TRUS)-guided random biopsy. Risk-based patient selection for mpMRI could help to avoid unnecessary mpMRIs.

OBJECTIVE

To study the rate of potentially avoided mpMRIs after negative TRUS-guided random biopsy by risk-based patient selection using the Rotterdam Prostate Cancer Risk Calculator (RPCRC).

DESIGN, SETTING, AND PARTICIPANTS

One hundred and twenty two consecutive men received a mpMRI scan and subsequent MRI-TRUS fusion targeted biopsy in case of suspicious lesion(s) (Prostate Imaging Reporting and Data System ≥ 3) after negative TRUS-guided random biopsy. Men were retrospectively stratified according to the RPCRC biopsy advice to compare targeted biopsy outcomes after risk-based patient selection with standard (prostate specific antigen and/or digital rectal examination-driven) patient selection.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The rate of potentially avoided mpMRIs by RPCRC-based patient selection in relation to the rate of missed high-grade (Gleason ≥ 3+4) PCa. Receiver operating characteristic curve analysis was performed to determine the area under the curve of the RPCRC for (high-grade) PCa.

RESULTS AND LIMITATIONS

Of the 60 men with a positive biopsy advice, six (10%) had low-grade PCa and 28 (47%) had high-grade PCa in targeted biopsy. Of the 62 men with a negative advice, two (3%) had low-grade PCa and three (5%) had high-grade PCa. Upfront RPCRC-based patient selection would have avoided 62 (51%) of 122 mpMRIs and two (25%) of eight low-grade PCa diagnoses, missing three (10%) of 31 high-grade PCa. The area under the curve of the RPCRC for PCa and high-grade PCa was respectively 0.76 (95% confidence interval 0.67-0.85) and 0.84 (95% confidence interval 0.76-0.93).

CONCLUSIONS

Risk-based patient selection with the RPCRC can avoid half of mpMRIs after a negative prostate specific antigen and/or digital rectal examination-driven TRUS-guided random biopsy. Further improvement in risk-based patient selection for mpMRI could be made by adjusting the RPCRC for MRI-targeted biopsy outcome prediction.

PATIENT SUMMARY

The suspicion of prostate cancer remains in many men after a negative ultrasound-guided prostate biopsy. These men increasingly receive an often unnecessary magnetic resonance imaging (MRI) scan. We found that patient selection for MRI based on the Rotterdam Prostate Cancer Risk Calculator biopsy advice could avoid half of the MRIs.

Comparison of Multiparametric MRI Scoring Systems and the Impact on Cancer Detection in Patients Undergoing MR US Fusion Guided Prostate Biopsies

Introduction

Multiple scoring systems have been proposed for prostate MRI reporting. We sought to review the clinical impact of the new Prostate Imaging Reporting and Data System v2 (PI-RADS) and compare those results to our proposed Simplified Qualitative System (SQS) score with respect to detection of prostate cancers and clinically significant prostate cancers.

Methods

All patients who underwent multiparametric prostate MRI (mpMRI) had their images interpreted using PI-RADS v1 and SQS score. PI-RADS v2 was calculated from prospectively collected data points. Patients with positive mpMRIs were then referred by their urologists for enrollment in an IRB-approved prospective phase III trial of mpMRI-Ultrasound (MR/TRUS) fusion biopsy of suspicious lesions. Standard 12-core biopsy was performed at the same setting. Clinical data were collected prospectively.

Results

1060 patients were imaged using mpMRI at our institution during the study period. 341 participants were then referred to the trial. 312 participants underwent MR/TRUS fusion biopsy of 452 lesions and were included in the analysis. 202 participants had biopsy-proven cancer (64.7%) and 206 (45.6%) lesions were positive for cancer. Distribution of cancer detected at each score produced a Gaussian distribution for SQS while PI-RADS demonstrates a negatively skewed curve with 82.1% of cases being scored as a 4 or 5. Patient-level data demonstrated AUC of 0.702 (95% CI 0.65 to 0.73) for PI-RADS and 0.762 (95% CI 0.72 to 0.81) for SQS (p< 0.0001) with respect to the detection of prostate cancer. The analysis for clinically significant prostate cancer at a per lesion level resulted in an AUC of 0.725 (95% CI 0.69 to 0.76) and 0.829 (95% CI 0.79 to 0.87) for the PI-RADS and SQS score, respectively (p< 0.0001).

Conclusions

mpMRI is a useful tool in the workup of patients at risk for prostate cancer, and serves as a platform to guide further evaluation with MR/TRUS fusion biopsy. SQS score provided a more normal distribution of scores and yielded a higher AUC than PI-RADS v2. However until our findings are validated, we recommend reporting of detailed sequence-specific findings. This will allow for prospectively collected data to be utilized in determining the impact of ongoing changes to these scoring systems as our understanding of mpMRI interpretation evolves.

Magnetic resonance imaging for prostate cancer: Comparative studies including radical prostatectomy specimens and template transperineal biopsy

Purpose

Multiparametric magnetic resonance imaging (mpMRI) is an emerging technique aiming to improve upon the diagnostic sensitivity of prostate biopsy. Because of variance in interpretation and application of techniques, results may vary. There is likely a learning curve to establish consistent reporting of mpMRI. This study aims to review current literature supporting the diagnostic utility of mpMRI when compared with radical prostatectomy (RP) and template transperineal biopsy (TTPB) specimens.

Methods

MEDLINE and PubMed database searches were conducted identifying relevant literature related to comparison of mpMRI with RP or TTPB histology.

Results

Data suggest that compared with RP and TTPB specimens, the sensitivity of mpMRI for prostate cancer (PCa) detection is 80–90% and the specificity for suspicious lesions is between 50% and 90%.

Conclusions

mpMRI has an increasing role for PCa diagnosis, staging, and directing management toward improving patient outcomes. Its sensitivity and specificity when compared with RP and TTPB specimens are less than what some expect, possibly reflecting a learning curve for the technique of mpMRI.

Current role of multiparametric magnetic resonance imaging for prostate cancer

Multiparametric magnetic resonance imaging (mp-MRI) has shown promising results in diagnosis, localization, risk stratification and staging of clinically significant prostate cancer, and targeting or guiding prostate biopsy. mp-MRI consists of T2-weighted imaging (T2WI) combined with several functional sequences including diffusion-weighted imaging (DWI), perfusion or dynamic contrast-enhanced imaging (DCEI) and spectroscopic imaging. Recently, mp-MRI has been used to assess prostate cancer aggressiveness and to identify anteriorly located tumors before and during active surveillance. Moreover, recent studies have reported that mp-MRI is a reliable imaging modality for detecting local recurrence after radical prostatectomy or external beam radiation therapy. Because assessment on mp-MRI can be subjective, use of the newly developed standardized reporting Prostate Imaging and Reporting Archiving Data System (PI-RADS) scoring system and education of specialist radiologists are essential for accurate interpretation. This review focuses on the current place of mp-MRI in prostate cancer and its evolving role in the management of prostate cancer.

Prostate MRI can reduce overdiagnosis and overtreatment of prostate cancer

The contemporary management of prostate cancer (PCa) has been criticized as fostering overdetection and overtreatment of indolent disease. In particular, the historical inability to identify those men with an elevated PSA who truly warrant biopsy, and, for those needing biopsy, to localize aggressive tumors within the prostate, has contributed to suboptimal diagnosis and treatment strategies. This article describes how modern multi-parametric MRI of the prostate addresses such challenges and reduces both overdiagnosis and overtreatment. The central role of diffusion-weighted imaging (DWI) in contributing to MRI's current impact is described. Prostate MRI incorporating DWI achieves higher sensitivity than standard systematic biopsy for intermediate-to-high risk tumor, while having lower sensitivity for low-grade tumors that are unlikely to impact longevity. Particular applications of prostate MRI that are explored include selection of a subset of men with clinical suspicion of PCa to undergo biopsy as well as reliable confirmation of only low-risk disease in active surveillance patients. Various challenges to redefining the standard of care to incorporate solely MRI-targeted cores, without concomitant standard systematic cores, are identified. These include needs for further technical optimization of current systems for performing MRI-targeted biopsies, enhanced education and expertise in prostate MRI among radiologists, greater standardization in prostate MRI reporting across centers, and recognition of the roles of pre-biopsy MRI and MRI-targeted biopsy by payers. Ultimately, it is hoped that the medical community in the United States will embrace prostate MRI and MRI-targeted biopsy, allowing all patients with known or suspected prostate cancer to benefit from this approach.

Prostate diffusion imaging with distortion correction

PURPOSE

Diffusion imaging in the prostate is susceptible to distortion from B0 inhomogeneity. Distortion correction in prostate imaging is not routinely performed, resulting in diffusion images without accurate localization of tumors. We performed and evaluated distortion correction for diffusion imaging in the prostate.

MATERIALS AND METHODS

28 patients underwent pre-operative MRI (T2, Gadolinium perfusion, diffusion at b=800 s/mm(2)). The restriction spectrum protocol parameters included b-values of 0, 800, 1500, and 4000 s/mm(2) in 30 directions for each nonzero b-value. To correct for distortion, forward and reverse trajectories were collected at b=0 s/mm(2). Distortion maps were generated to reflect the offset of the collected data versus the corrected data. Whole-mount histology was available for correlation.

RESULTS

Across the 27 patients evaluated (excluding one patient due to data collection error), the average root mean square distortion distance of the prostate was 3.1 mm (standard deviation, 2.2mm; and maximum distortion, 12 mm).

CONCLUSION

Improved localization of prostate cancer by MRI will allow better surgical planning, targeted biopsies and image-guided treatment therapies. Distortion distances of up to 12 mm due to standard diffusion imaging may grossly misdirect treatment decisions. Distortion correction for diffusion imaging in the prostate improves tumor localization.

Multiparametric-MRI in diagnosis of prostate cancer

Multiparametric-magnetic resonance imaging (mp-MRI) has shown promising results in diagnosis, localization, risk stratification and staging of clinically significant prostate cancer. It has also opened up opportunities for focal treatment of prostate cancer. Combinations of T2-weighted imaging, diffusion imaging, perfusion (dynamic contrast-enhanced imaging) and spectroscopic imaging have been used in mp-MRI assessment of prostate cancer, but T2 morphologic assessment and functional assessment by diffusion imaging remains the mainstay for prostate cancer diagnosis on mp-MRI. Because assessment on mp-MRI can be subjective, use of the newly developed standardized reporting Prostate Imaging and Reporting Archiving Data System scoring system and education of specialist radiologists are essential for accurate interpretation. This review focuses on the present status of mp-MRI in prostate cancer and its evolving role in the management of prostate cancer.

Magnetic resonance imaging detected prostate evasive anterior tumours: Further insights

INTRODUCTION

Clinical confusion continues to exist regarding the underestimation of cancers among patients on active surveillance and among men with repeated negative prostate biopsies despite worrisome prostate-specific antigen (PSA) levels. We have previously described our initial experience with magnetic resonance imaging (MRI)-based detection of tumours in the anterior prostate gland. In this report, we update and expand our experience with these tumours in terms of multiparametric-MRI findings, staging, and grading. Furthermore, we report early treatment outcomes with these unique cancers.

METHODS

We reviewed our prostate MRI dataset of 1117 cases from January 2006 until December 2012 and identified 189 patients who fulfilled criteria for prostate evasive anterior tumors (PEATS). Descriptive analyses were performed on multiple covariates. Kaplan-Meier actuarial technique was used to plot the treatment-related outcomes from PEATS tumours.

RESULTS

Among the 189 patients who had MRI-detectable anterior tumours, 148 had biopsy proven disease in the anterior zone. Among these tumours, the average PSA was 18.3 ng/mL and most cancers were Gleason 7. In total, 68 patients chose surgical therapy. Among these men, most of their cancers had extra prostatic extension and 46% had positive surgical margins. Interestingly, upgrading of tumours that were biopsy Gleason 6 in the anterior zone was common, with 59% exhibiting upgrading to Gleason 7 or higher. Biochemical-free survival among men who elected surgery was not ideal, with 20% failing by 20 months.

CONCLUSION

PEATS tumours are found late and are disproportionally high grade tumours. Careful consideration to MRI testing should be given to men at risk for PEATS.

Multiparametric MRI for detection of radiorecurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images

BACKGROUND

Multiparametric magnetic resonance imaging (mp-MRI) is increasingly advocated for prostate cancer detection. There are limited reports of its use in the setting of radiorecurrent disease. Our aim was to assess mp-MRI for detection of radiorecurrent prostate cancer and examine the added value of its functional sequences.

METHODS

Thirty-seven men with mean age of 69.7 (interquartile range, 66-74) with biochemical failure after external beam radiotherapy underwent mp-MRI (T2-weighted, high b-value, multi-b-value apparent diffusion coefficient (ADC) and dynamic contrast-enhanced (DCE) imaging); then transperineal systematic template prostate mapping (TPM) biopsy. Using a locked sequential read paradigm (with the sequence order above), two experienced radiologists independently reported mp-MRI studies using score 1-5. Radiologist scores were matched with TPM histopathology at the hemigland level (n=74). Accuracy statistics were derived for each reader. Interobserver agreement was evaluated using kappa statistics.

RESULTS

Receiver-operator characteristic area under curve (AUC) for readers 1 and 2 increased from 0.67 (95% confidence interval (CI), 0.55-0.80) to 0.80 (95% CI, 0.69-0.91) and from 0.67 (95% CI, 0.55-0.80) to 0.84 (95% CI, 0.76-0.93), respectively, between T2-weighted imaging alone and full mp-MRI reads. Addition of ADC maps and DCE imaging to the examination did not significantly improve AUC for either reader (P=0.08 and 0.47 after adding ADC, P=0.90 and 0.27 after adding DCE imaging) compared with T2+high b-value review. Inter-reader agreement increased from k=0.39 to k=0.65 between T2 and full mp-MRI review.

CONCLUSIONS

mp-MRI can detect radiorecurrent prostate cancer. The optimal examination included T2-weighted imaging and high b-value DWI; adding ADC maps and DCE imaging did not significantly improve the diagnostic accuracy.

Multiparametric magnetic resonance imaging predicts the presence of prostate cancer in patients with negative prostate biopsy

OBJECTIVE

To assess the ability of multiparametric prostate magnetic resonance imaging (mpMRI) to detect prostate cancer in patients with prior negative transrectal prostate biopsy (TPB).

MATERIAL AND METHODS

mpMRI (TSE-T2-w, DWI and DCE sequences) was performed on 1.5T (Magnetom Avanto; Siemens Healthcare Solutions) in 150 patients suspicious of prostate cancer and with negative TPB. European Society of Urogenital Radiology (ESUR) criteria were used (score 1: clinically significant disease is highly unlikely to be present; score 2: clinically significant cancer is unlikely to be present; score 3: clinically significant cancer is equivocal; score 4: clinically significant cancer is likely to be present; score 5: clinically significant cancer is highly likely to be present). PSA measurement (total and free), digital rectal examination (DRE), transrectal ultrasound (TRU) and a second TPB (at least 14 cylinders) were performed in all patients. Variables were submitted for independent blind analysis. The accuracy of each test was measured. Stepwise selection model for prediction of prostate cancer in second TPB was developed.

RESULTS

Mean age was 66.2± 5 years (51-77), mean PSA 11.3± 9.6ng/mL (0.9-75) and mean prostatic volume 82.2±42 (20-250) cc. DRE was suspicious in 11 (7.3%) patients. The mean number of cylinders per patient sampled in second TRB was 17.6±2.7(14-22). Second TRB was positive in 28 patients (18.7%). mpMRI was positive (score 3-5) in 102 (68%), test sensibility was 92.9% and the NPV was 95.8%. The risk of prostate cancer diagnosis in second TPB is modified by: PSA velocity > 0.75 (OR 1.04 [0.99-1.08]; P=0.06), free/total ratio PSA <15% (OR 0.37 [0.13-1.05]; P=0.06), each cc. of prostate volume (OR 0.98 [0.97-1]; P=0.017) and mpMRI 3-5 (OR 7.87 [1.78-34.7]; P=0.006). Multivariate analysis reveals that mpMRI (OR 7.41 [1.65-33.28]; P=0.009) and prostatic volume (OR 0.31 [0.12-0.78]; P=0.01) are independent risk predictors of prostate cancer.

CONCLUSIONS

According to ESUR guidelines and in patients with prior negative prostate biopsy, mpMRI is a valuable tool for the prediction of prostate cancer in second TPB. Lower prostate volume, the higher reliability.

Can Clinically Significant Prostate Cancer Be Detected with Multiparametric Magnetic Resonance Imaging? A Systematic Review of the Literature

CONTEXT

Detection of clinically significant prostate cancer (PCa) is a major challenge. It has been shown that multiparametric magnetic resonance imaging (mpMRI) facilitates localisation of PCa and can help in targeting prostate biopsy.

OBJECTIVE

To systematically review the literature to determine the diagnostic accuracy of mpMRI in the detection of clinically significant PCa.

EVIDENCE ACQUISITION

The Pubmed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from January 1, 2000 to September 30, 2014, using the search criteria "prostate OR Pca OR PSA OR prostatic OR prostate cancer" AND "MR OR NMR OR NMRI OR MRI OR magnetic resonance OR ADC OR DWI OR DCE OR diffusion weighted OR dynamic contrast OR multiparametric OR MRSI OR MR spectroscopy". Two reviewers independently assessed 1729 records. Two independent reviewers assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) 2 tool.

EVIDENCE SYNTHESIS

Twelve articles were eventually selected. Patients had a median age of 62-65 yr (range 39-83 yr), a median prostate-specific antigen (PSA) level of 5.1-13.4 ng/ml (range 1.2-228 ng/ml), and Gleason score of 6-10. Various definitions of clinical significance were used, mainly based on maximum cancer core length and grade at biopsy, number of positive cores, and PSA. Detection of clinically significant PCa using mpMRI ranged from 44% to 87% in biopsy-naïve males and men with prior negative biopsies using prostate biopsy or definitive pathology of a radical prostatectomy specimen as the reference standard. The negative predictive value for exclusion of significant disease ranged from 63% to 98%.

CONCLUSIONS

mpMRI is able to detect significant PCa in biopsy-naïve males and men with prior negative biopsies. The negative predictive value of mpMRI is important to the clinician because mpMRI could be used to rule out significant disease. This may result in fewer or no systematic or targeted biopsies in patients with PSA suspicious for prostate cancer.

PATIENT SUMMARY

We reviewed the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI) for the detection of clinically significant prostate cancer (PCa). We conclude that mpMRI is able to detect significant PCa and may used to target prostate biopsies.

Novel technique for characterizing prostate cancer utilizing MRI restriction spectrum imaging: proof of principle and initial clinical experience with extraprostatic extension

BACKGROUND

Standard magnetic resonance imaging (MRI) of the prostate lacks sensitivity in the diagnosis and staging of prostate cancer (PCa). To improve the operating characteristics of prostate MRI in the detection and characterization of PCa, we developed a novel, enhanced MRI diffusion technique using restriction spectrum imaging (RSI-MRI).

METHODS

We compared the efficacy of our novel RSI-MRI technique with standard MRI for detecting extraprostatic extension (EPE) among 28 PCa patients who underwent MRI and RSI-MRI prior to radical prostatectomy, 10 with histologically proven pT3 disease. RSI cellularity maps isolating the restricted isotropic water fraction were reconstructed based on all b-values and then standardized across the sample with z-score maps. Distortion correction of the RSI maps was performed using the alternating phase-encode technique.

RESULTS

27 patients were evaluated, excluding one patient where distortion could not be performed. Preoperative standard MRI correctly identified extraprostatic the extension in two of the nine pT3 (22%) patients, whereas RSI-MRI identified EPE in eight of nine (89%) patients. RSI-MRI correctly identified pT2 disease in the remaining 18 patients.

CONCLUSIONS

In this proof of principle study, we conclude that our novel RSI-MRI technology is feasible and shows promise for substantially improving PCa imaging. Further translational studies of prostate RSI-MRI in the diagnosis and staging of PCa are indicated.

Use of the Prostate Imaging Reporting and Data System (PI-RADS) for Prostate Cancer Detection with Multiparametric Magnetic Resonance Imaging: A Diagnostic Meta-analysis

CONTEXT

In 2012, an expert panel of the European Society of Urogenital Radiology (ESUR) published the Prostate Imaging Reporting and Data System (PI-RADS) for prostate cancer (PC) detection with multiparametric magnetic resonance imaging (mp-MRI). Since then, many centers have reported their experiences.

PURPOSE

To review the diagnostic accuracy of PI-RADS for PC detection with mp-MRI.

EVIDENCE ACQUISITION

We searched Medline and Embase up to March 20, 2014. We included diagnostic accuracy studies since 2012 that used PI-RADS with mp-MRI for PC detection in men, using prostatectomy or biopsy as the reference standard. The methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool by two independent reviewers. Data necessary to complete 2×2 contingency tables were obtained from the included studies, and test characteristics including sensitivity and specificity were calculated. Results were pooled and plotted in a summary receiver operating characteristics plot.

EVIDENCE SYNTHESIS

Fourteen studies (1785 patients) could be analyzed. The pooled data showed sensitivity of 0.78 (95% confidence interval [CI] 0.70-0.84) and specificity of 0.79 (95% CI 0.68-0.86) for PC detection, with negative predictive values ranging from 0.58 to 0.95. Sensitivity analysis revealed pooled sensitivity of 0.82 (95% CI 0.72-0.89) and specificity of 0.82 (95% CI 0.67-0.92) in studies with correct use of PI-RADS (ie, clear description in the methodology and no adjustment of criteria). For studies with a less strict or adjusted use of PI-RADS criteria, or unclear description of the methodology, had pooled sensitivity of 0.73 (95% CI 0.62-0.82) and specificity of 0.75 (95% CI 0.61-0.84).

CONCLUSIONS

In patients for whom PC is suspected, PI-RADS appears to have good diagnostic accuracy in PC detection, but no recommendation regarding the best threshold can be provided because of heterogeneity.

PATIENT SUMMARY

Pooling of results from all previous studies that used a relatively new 5-point scoring system for prostate magnetic resonance imaging showed that this scoring system appears to be able to detect prostate cancer accurately.

Will Multi-Parametric Magnetic Resonance Imaging be the Future Tool to Detect Clinically Significant Prostate Cancer?

Multi-parametric magnetic resonance imaging is an emerging imaging modality for diagnosis, staging, characterization, and treatment planning of prostate cancer. In this report, we reviewed the literature for studies assessing the accuracy of multi-parametric magnetic resonance imaging in detecting clinically significant prostate cancer, and we critically examined the future role of this imaging tool in various clinical diagnostic settings. There is accumulating evidence suggesting a high accuracy of multi-parametric magnetic resonance imaging in ruling out clinically significant disease. Although definition for clinically significant disease widely varies, the negative predictive value is very high at up to 98%. Multi-parametric magnetic resonance imaging should, thus, be further evaluated for application in different clinical scenarios in which it is desirable to reduce the proportion of unnecessary prostate biopsies and to limit the detection of indolent disease, such as opportunistic screening, persistent prostate cancer suspicion in men with previous negative prostate biopsies, and eligibility for active surveillance. Continued improvement in standardization of technical parameters, functional sequences, and image reporting systems is a pre-requisite for a rapid and successful dissemination of this imaging modality.

[Radiological diagnostics in CUP syndrome]

CLINICAL/METHODICAL ISSUE

Imaging plays an essential role in the therapeutic management of cancer of unknown primary (CUP) patients for localizing the primary tumor, for the identification of tumor entities for which a dedicated therapy regimen is available and for the characterization of clinicopathological subentities that direct the subsequent diagnostic and therapeutic strategy.

STANDARD RADIOLOGICAL METHODS

Modalities include conventional x-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound as well as positron emission tomography (PET)-CT and MRI-PET.

PERFORMANCE

In whole body imaging CT has a high sensitivity for tumor entities which frequently present as a metastasized cancer illness. According to the current literature CT is diagnostic in 86% of patients with pancreatic carcinoma, in 36% of patients with colon carcinoma and in 74% of patients with lung carcinoma. Additionally a meta-analysis showed that for patients with squamous cell carcinoma and cervical lymph node metastases a positive diagnosis was possible in 22% of the cases using CT, in 36% using MRI and in 28-57% using 18F-fluorodeoxyglucose PET-CT ((18)F-FDG PET-CT). In addition, MRI plays an important role in the localization of primary occult tumors (e.g. breast and prostate) because of its high soft tissue contrast and options for functional imaging.

ACHIEVEMENTS

At the beginning of the diagnostic algorithm stands the search for a possible primary tumor and CT of the neck, thorax and abdomen is most frequently used for whole body staging. Subsequent organ-specific imaging examinations follow, e.g. mammography in women with axillary lymphadenopathy. For histological and immunohistochemical characterization of tumor tissue, imaging is also applied to identify the most accessible and representative tumor manifestation for biopsy. Tumor biopsy may be guided by CT, MRI or ultrasound and MRI also plays a central role in the localization of primary occult tumors because of superior soft tissue contrast and options for functional imaging (perfusion, diffusion), e.g. investigation of breast carcinoma or prostate carcinoma.

PRACTICAL RECOMMENDATIONS

Whole body staging stands at the beginning of the diagnostic algorithm in CUP syndrome to localize a potential primary tumor. Clinically, contrast-enhanced CT of the neck, thorax and abdomen is frequently applied; however, many studies have demonstrated augmented sensitivity of (18)F-FDG PET-CT for the detection of primary tumors and metastatic tumor manifestations.

Diagnostic accuracy of magnetic resonance imaging (MRI) prostate imaging reporting and data system (PI-RADS) scoring in a transperineal prostate biopsy setting

OBJECTIVES

To determine the sensitivity and specificity of multiparametric magnetic resonance imaging (mpMRI) for significant prostate cancer with transperineal sector biopsy (TPSB) as the reference standard.

PATIENTS AND METHODS

The study included consecutive patients who presented for TPSB between July 2012 and November 2013 after mpMRI (T2- and diffusion-weighted images, 1.5 Tesla scanner, 8-channel body coil). A specialist uro-radiologist, blinded to clinical details, assigned qualitative prostate imaging reporting and data system (PI-RADS) scores on a Likert-type scale, denoting the likelihood of significant prostate cancer as follows: 1, highly unlikely; 3, equivocal; and 5, highly likely. TPSBs sampled 24-40 cores (depending on prostate size) per patient. Significant prostate cancer was defined as the presence of Gleason pattern 4 or cancer core length ≥6 mm.

RESULTS

A total of 201 patients were included in the analysis. Indications were: a previous negative transrectal biopsy with continued suspicion of prostate cancer (n = 103); primary biopsy (n = 83); and active surveillance (n = 15). Patients' mean (±sd) age, prostate-specific antigen and prostate volumes were 65 (±7) years, 12.8 (±12.4) ng/mL and 62 (±36) mL, respectively. Overall, biopsies were benign, clinically insignificant and clinically significant in 124 (62%), 20 (10%) and 57 (28%) patients, respectively. Two of 88 men with a PI-RADS score of 1 or 2 had significant prostate cancer, giving a sensitivity of 97% (95% confidence interval [CI] 87-99) and a specificity of 60% (95% CI 51-68) at this threshold. Receiver-operator curve analysis gave an area under the curve of 0.89 (95% CI 0.82-0.92). The negative predictive value of a PI-RADS score of ≤2 for clinically significant prostate cancer was 97.7%

CONCLUSION

We found that PI-RADS scoring performs well as a predictor for biopsy outcome and could be used in the decision-making process for prostate biopsy.

Multimodal imaging for improved diagnosis and treatment of cancers

The authors review methods for image-guided diagnosis and therapy that increase precision in the detection, characterization, and localization of many forms of cancer to achieve optimal target definition and complete resection or ablation. A new model of translational, clinical, image-guided therapy research is presented, and the Advanced Multimodality Image-Guided Operating (AMIGO) suite is described. AMIGO was conceived and designed to allow for the full integration of imaging in cancer diagnosis and treatment. Examples are drawn from over 500 procedures performed on brain, neck, spine, thorax (breast, lung), and pelvis (prostate and gynecologic) areas and are used to describe how they address some of the many challenges of treating brain, prostate, and lung tumors. Cancer 2015;121:817-827. © 2014 American Cancer Society.

Multiparametric MRI in the PSA screening era

Prostate cancer remains significant public health concern amid growing controversies regarding prostate specific antigen (PSA) based screening. The utility of PSA has been brought into question, and alternative measures are investigated to remedy the overdetection of indolent disease and safeguard patients from the potential harms resulting from an elevated PSA. Multiparametric MRI of the prostate has shown promise in identifying patients at risk for clinically significant disease but its role within the current diagnostic and treatment paradigm remains in question. The current review focuses on recent applications of MRI in this pathway.