Tag Archive for: magnetic resonance imaging

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Article of the week: A clinical prediction tool to determine the need for concurrent systematic sampling at the time of MRI‐guided biopsy

Every week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an editorial written by a prominent member of the urological community. These are intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation. 

If you only have time to read one article this week, it should be this one.

A clinical prediction tool to determine the need for concurrent systematic sampling at the time of magnetic resonance imaging‐guided biopsy

Niranjan J. Sathianathen*, Christopher A. Warlick*, Christopher J. Weight*, Maria A. Ordonez*, Benjamin Spilseth, Gregory J. Metzger, Paari Muruganand Badrinath R. Konety*

 

Departments of *Urology, Radiology, and Pathology, University of Minnesota, Minneapolis, MN, USA

 

Abstract

Objective

To develop a clinical prediction tool that characterises the risk of missing significant prostate cancer by omitting systematic biopsy in men undergoing transrectal ultrasonography/magnetic resonance imaging (TRUS/MRI)‐fusion‐guided biopsy.

Patients and methods

A consecutive sample of men undergoing TRUS/MRI‐fusion‐guided biopsy with the UroNav® system (Invivo International, Best, The Netherlands) who also underwent concurrent systematic biopsy was included. By comparing the grade of cancer diagnosed on targeted and systematic biopsy cores, we identified cases where clinically significant disease (Gleason score ≥3+4) was only found on systematic and not targeted cores. Multivariable logistic regression analyses were used to identify predictive factors for finding significant cancer on systematic cores only. We then used these data to develop a nomogram and evaluated its utility using decision curve analysis.

Fig 1. Nomogram for predicting the diagnosis of clinically significant on systematic biopsy only and missed on targeted biopsy.

Results

Of the 398 men undergoing TRUS/MRI‐fusion‐guided biopsy in our study, there were 46 (11.6%) cases in which clinically significant cancer was missed on targeted biopsy and detected on systematic biopsy. The clinical setting, number of MRI lesions identified, and the highest Prostate Imaging‐Reporting and Data System (PI‐RADS) score of the lesions, were all found to be predictors of this. Our model had a good discriminative ability (concordance index = 0.70). The results from our decision curve analysis show that this model provides a higher net clinical benefit than either biopsying all men or omitting biopsy in all patients when the threshold probability is <30%.

Conclusion

We found that omitting concurrent systematic biopsy in men undergoing TRUS/MRI‐fusion‐guided biopsy would miss significant disease in more than one in 10 patients. We propose a prediction model with good discriminative ability that can be used to improve patient selection for performing concurrent systematic biopsy in order to minimise the number of missed significant cancers. It is important that our model is validated in external cohorts before being employed in routine clinical practice.

Editorial: Can systematic biopsy be safely avoided at the time of MRI/ultrasonography fusion biopsy?

In clinical practice, the need for maximising prostate cancer detection is often balanced against the theoretical risks of infection, bleeding, and pain associated with taking additional cores. In this novel study, Sathianathen et al. [1] provide a tool for measuring the oncological benefit of including concurrent systematic biopsy (SB) at the time of MRI‐guided targeted biopsy (TB). There were several key findings: (i) Amongst patients undergoing MRI‐guided biopsy (all biopsy settings), 11.6% were found to have significant cancers detected by SB alone; (ii) Amongst patients who had clinically significant cancers detected by SB alone, 52.2% were sampled within sextants outside the targeted regions of interest; (iii) According to the proposed nomogram, patients with prior negative biopsies, fewer MRI lesions, and lower Prostate Imaging‐Reporting and Data System (PI‐RADS) scores were at the lowest risk of missing significant cancer when SB was omitted.

Based on the present study, biopsy setting appears to be a key factor for deciding whether to omit SB. In the subset of patients undergoing primary biopsy, the authors found that 18.5% of cancers were detected by SB alone. These results are consistent with those of the MRI‐FIRST trial, which showed 14% of cancers were detected by SB only, 20% by TB only, and 66% by combining both techniques [2]. MRI‐FIRST concluded that in the primary biopsy setting, there was no difference between SB and TB in detection of clinically significant prostate cancer, although combining both techniques provided the highest detection rate.

Prior negative biopsy cohorts are generally at lower risk of harbouring significant cancer, as many cancers have already been ‘selected out’ by initial biopsies. In this setting, TB plays an important role in sampling tumour foci in difficult‐to‐reach regions of the prostate (e.g., anterior and apical) [3]. According to the authors’ nomogram, prior negative biopsy patients were least likely to benefit from concurrent SB. While the authors suggest a paradigm of selectively omitting SB, some authors have proposed omitting both TB and SB altogether in select patients. A previously reported multi‐institutional nomogram can be used to predict benign pathology after MRI‐guided biopsy, which can help reduce the number of unnecessary biopsies after MRI in the prior negative biopsy setting [4]. This clinical tool was further externally validated and optimised by Bjurlin et al. [5].

The ‘active surveillance (AS)’ setting typically refers to a confirmatory MRI‐guided biopsy in men with Grade Group 1 prostate cancer prior to enrollment in AS. Recently, the presence of cribriform morphology in Grade Group 2 patients was confirmed to be a key poor prognostic feature that would exclude patients from AS [6]. The present study, however, did not account for different Gleason pattern 4 morphologies in their analysis, as ‘significant cancer’ was defined by Grade Group alone. Studies by independent groups have found that TB combined with SB was more accurate than either modality alone for detecting cribriform at the time of MRI‐guided biopsy [78]. Therefore, concurrent SB is required to properly sample cribriform cancers in patients who are considering AS.

In this study, Sathianathen et al. [1] provide clinicians with a clinical tool for quantifying the added oncological value of concurrent SB. However, concurrent SB is probably prudent for most patients, particularly for those considering AS or focal therapy for which accurate determination of whole gland grade, cancer volume, and cribriform status are essential. As reducing the number of cores has not yet been shown to reduce biopsy‐related complications, are we willing to suboptimise cancer sampling without proven compensation?

by Matthew Truong

References

  1. Sathianathen, NJWarlick, CAWeight, CJ et al. A clinical prediction tool to determine the need for concurrent systematic sampling at the time of magnetic resonance imaging‐guided biopsy. BJU 2019123612– 7
  2. Salami, SSBen‐Levi, EYaskiv, O et al. In patients with a previous negative prostate biopsy and a suspicious lesion on magnetic resonance imaging, is a 12‐core biopsy still necessary in addition to a targeted biopsy? BJU Int 2015115562– 70
  3. Truong, MWang, BGordetsky, JB et al. Multi‐institutional nomogram predicting benign prostate pathology on magnetic resonance/ultrasound fusion biopsy in men with a prior negative 12‐core systematic biopsy. Cancer 2018124278– 85
  4. Bjurlin, MARenson, ARais‐Bahrami, S et al. Predicting benign prostate pathology on magnetic resonance imaging/ultrasound fusion biopsy in men with a prior negative 12‐core systematic biopsy: external validation of a prognostic nomogram. Eur Urol Focus 2018. [Epub ahead of print] https://doi.org/10.1016/j.euf.2018.05.005
  5. Kweldam, CFKümmerlin, IPNieboer, D et al. Presence of invasive cribriform or intraductal growth at biopsy outperforms percentage grade 4 in predicting outcome of Gleason score 3+4=7 prostate cancer. Mod Pathol 2017301126– 32
  6. Truong, MFeng, CHollenberg, G et al. A comprehensive analysis of cribriform morphology on magnetic resonance imaging/ultrasound fusion biopsy correlated with radical prostatectomy specimens. J Urol 2018199106– 13
  7. Prendeville, SGertner, MMaganti, M et al. Role of magnetic resonance imaging targeted biopsy in detection of prostate cancer harboring adverse pathological features of intraductal carcinoma and invasive cribriform carcinoma. J Urol 2018200104– 13

 

 

Article of the week: Ultrasound characteristics of regions identified as suspicious by MRI predict the likelihood of clinically significant cancer on MRI–ultrasound fusion‐targeted biopsy

Every week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an editorial written by a prominent member of the urological community, and a video made by the authors. These are intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation. 

If you only have time to read one article this week, it should be this one.

 

The ultrasound characteristics of regions identified as suspicious by magnetic resonance imaging (MRI) predict the likelihood of clinically significant cancer on MRI–ultrasound fusion‐targeted biopsy

Benjamin Press*, Andrew B. Rosenkrantz, Richard Huang and Samir S. Taneja§ 
 
*Rutgers New Jersey Medical School, Newark, NJ, Department of Radiology, Department of Urology, and §Departments of Urology and Radiology, NYU Langone Health, New York, NY, USA
 

Abstract

Objective

To determine whether the presence of an ultrasound hypoechoic region at the site of a region of interest (ROI) on magnetic resonance imaging (MRI) results in improved prostate cancer (PCa) detection and predicts clinically significant PCa on MRI–ultrasonography fusion‐targeted prostate biopsy (MRF‐TB).

Materials and Methods

Between July 2011 and June 2017, 1058 men who underwent MRF‐TB, with or without systematic biopsy, by a single surgeon were prospectively entered into an institutional review board‐approved database. Each MRI ROI was identified and scored for suspicion by a single radiologist, and was prospectively evaluated for presence of a hypoechoic region at the site by the surgeon and graded as 0, 1 or 2, representing none, a poorly demarcated ROI‐HyR, or a well demarcated ROI‐HyR, respectively. The interaction of MRI suspicion score (mSS) and ultrasonography grade (USG), and the prediction of cancer detection rate by USG, were evaluated through univariate and multivariate analysis.

Results

For 672 men, the overall and Gleason score (GS) ≥7 cancer detection rates were 61.2% and 39.6%, respectively. The cancer detection rates for USGs 0, 1 and 2 were 46.2%, 58.6% and 76.0% (P < 0.001) for any cancer, and 18.7%, 35.2% and 61.1% (P < 0.001) for GS ≥7 cancer, respectively. For MRF‐TB only, the GS ≥7 cancer detection rates for USG 0, 1 and 2 were 12.8%, 25.7% and 52.0%, respectively (P < 0.001). On univariate analysis, in men with mSS 2–4, USG was predictive of GS ≥7 cancer detection rate. Multivariable regression analysis showed that USG, prostate‐specific antigen density and mSS were predictive of GS ≥7 PCa on MRF‐TB.

Conclusions

Ultrasonography findings at the site of an MRI ROI independently predict the likelihood of GS ≥7 PCa, as men with a well‐demarcated ROI‐HyR at the time of MRF‐TB have a higher risk than men without.

Editorial: Is transrectal ultrasonography of the prostate obsolete in the MRI era?

Sampling of prostate tissue to confirm pathologically a clinical suspicion of cancer has undergone an exponential change. The random systematic prostate biopsy technique was the only method used for many decades, initially guided by the finger but, since 1989, performed with TRUS guidance. Now, within the space of only a few years, we have entered the era of performing prostate biopsies on the basis of high‐tech three‐dimensional multiparametric MRI images, including software that can track the exact course of the biopsy needle [1]. While new technical developments in general lead to better, more individually directed healthcare, there is always the risk of abandoning ‘old’ but well developed and extensively tested techniques too soon. In this issue of the BJUI, Press et al. [2] looked at the added value of the presence of an ‘old‐fashioned’ TRUS‐detected lesion in cancer‐suspicious regions on MRI to better predict the presence of clinically significant prostate cancer (csPCa) defined as Gleason score ≥7. In their study comprising 1058 men, it was shown that a well‐demarcated abnormal TRUS finding noted at the time of MRI‐TRUS fusion‐guided prostate biopsy coincides with an increased risk of csPCa detection, independent of MRI suspicion (Prostate Imaging Reporting and Data System [PI‐RADS] score).

Increasing PI‐RADS score is correlated with an increased percentage of csPCa after targeted biopsy, both at initial and repeat biopsy. In a review based on data from 8252 men, it was shown that there is a gradual increase in the detection of csPCa from PI‐RADS 3 to PI‐RADS 4 to PI‐RADS 5 index lesions. For example, at first biopsy, the overall rate of PCa detection and the percentage of csPCa were 39%, 62% and 92% and 54%, 63% and 76% for PI‐RADS 3, 4 and 5 lesions, respectively. This means that in men with PI‐RADS 3 lesions, representing approximately one‐third of men deemed eligible for further assessment, only 39% will be diagnosed with PCa and half of the PCa detected will be potentially indolent Gleason 6 PCa [3]. This makes this group of men extremely interesting for further risk stratification before biopsy. Multivariable risk stratification in which PSA density plays an important role has been shown to be of value in these men [4] but further refinement could potentially be made by including suspicious lesions identified at TRUS.

Apart from the added value of TRUS findings in terms of risk stratification, the performance of the MRI‐targeted biopsy itself could be improved by visual guidance of hypoechoic lesions. In the present study by Press et al [2], a hypoechoic TRUS lesion was present at or near the location of two‐thirds of cancer‐suspicious lesions on MRI. The authors more or less advise to direct the targeted biopsy cores not only to the MRI suspicious lesion, but also the TRUS suspicious lesion, both of which often do not fully overlay in a software‐assisted MRI‐TRUS fusion model. The extent to which this ‘correction for misregistration’ is already included during targeted biopsy in current clinical practice is unknown. Although feasible and seemingly important during software‐assisted fusion targeted biopsy, TRUS lesions in cancer‐suspicious MRI regions might be more frequently targeted during cognitive fusion‐targeted biopsy. Two recent studies underline the important message of the present study, and show that a considerable proportion of csPCa is missed in and around MRI‐suspicious lesions by targeted biopsies, as a result of sampling errors related to both misregistration and intra‐tumour heterogeneity [56]. As suggested by these studies, visual guidance by hypoechoic lesions and ‘focal saturation’ biopsy by additional (peri‐)lesional cores might improve the detection of csPCa.

In summary, ‘good old’ TRUS could be of value in those patients who are virtually always present in scenarios in which a grading system is being used, i.e. patients belonging to the so‐called grey zone. The challenge of risk stratification (i.e. personalized medicine) is to nibble at both sides of the grey zone by implementing new techniques or, more likely by implementing a combination of all available and relevant knowledge.

by Monique J. Roobol, Frank-Jan H. Drost and Arnout R. Alberts

References

  1. Verma, SChoyke, PLEberhardt, SC et al. The current state of MR imaging‐targeted biopsy techniques for detection of prostate cancer. Radiology 201728534356
  2. Press, BRosenkrantz, ABHuang, RTaneja, SSThe ultrasound characteristics of MRI suspicious regions predict the likelihood of clinically significant cancer on MRI‐ultrasound fusion targeted biopsy. BJUI 201912343946.
  3. Schoots, IGMRI in early prostate cancer detection: how to manage indeterminate or equivocal PI‐RADS 3 lesions? Transl Androl Urol 201877082
  4. Alberts, ARSchoots, IGBokhorst, LPLeenders, GJBangma, CHRoobol, MJRisk‐based patient selection for magnetic resonance imaging‐targeted prostate biopsy after negative transrectal ultrasound‐guided random biopsy avoids unnecessary magnetic resonance imaging scans. Eur Urol 201669112934
  5. Simmons, LAMKanthabalan, AArya, M et al. Accuracy of transperineal targeted prostate biopsies, visual estimation and image fusion in men needing repeat biopsy in the PICTURE trial. J Urol 2018200122734
  6. Leest, M, Cornel, EIsrael, B et al. Head‐to‐head comparison of transrectal ultrasound‐guided prostate biopsy versus multiparametric prostate resonance imaging with subsequent magnetic resonance‐guided biopsy in biopsy‐naive men with elevated prostate‐specific antigen: a large prospective multicenter clinical study. Eur Urol 2018; [Epub ahead of print]. https://doi.org/10.1016/j.eururo.2018.11.023.

 

Residents’ podcast: Implementation of mpMRI technology for evaluation of PCa in the clinic

Giulia Lane M.D. is a Fellow in Neuro-urology and Pelvic Reconstruction in the Department of Urology at the University of Michigan; Kyle Johnson is a Urology Resident in the same department.

In this podcast they discuss the following BJUI Article of the Month:

Implementation of multiparametric magnetic resonance imaging technology for evaluation of patients with suspicion for prostate cancer in the clinical practice setting

Abstract

Objectives

To investigate the impact of implementing magnetic resonance imaging (MRI) and ultrasonography fusion technology on biopsy and prostate cancer (PCa) detection rates in men presenting with clinical suspicion for PCa in the clinical practice setting.

Patients and Methods

We performed a review of 1 808 consecutive men referred for elevated prostate‐specific antigen (PSA) level between 2011 and 2014. The study population was divided into two groups based on whether MRI was used as a risk stratification tool. Univariable and multivariable analyses of biopsy rates and overall and clinically significant PCa detection rates between groups were performed.

Results

The MRI and PSA‐only groups consisted of 1 020 and 788 patients, respectively. A total of 465 patients (45.6%) in the MRI group and 442 (56.1%) in the PSA‐only group underwent biopsy, corresponding to an 18.7% decrease in the proportion of patients receiving biopsy in the MRI group (P < 0.001). Overall PCa (56.8% vs 40.7%; P < 0.001) and clinically significant PCa detection (47.3% vs 31.0%; P < 0.001) was significantly higher in the MRI vs the PSA‐only group. In logistic regression analyses, the odds of overall PCa detection (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.29–2.35; P < 0.001) and clinically significant PCa detection (OR 2.04, 95% CI 1.48–2.80; P < 0.001) were higher in the MRI than in the PSA‐only group after adjusting for clinically relevant PCa variables.

Conclusion

Among men presenting with clinical suspicion for PCa, addition of MRI increases detection of clinically significant cancers while reducing prostate biopsy rates when implemented in a clinical practice setting.

BJUI Podcasts now available on iTunes, subscribe here https://itunes.apple.com/gb/podcast/bju-international/id1309570262

 

Article of the month: Implementation of multiparametric MRI technology for evaluation of PCa in the clinic

Every month, the Editor-in-Chief selects an Article of the Month from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an editorial written by a prominent member of the urological community, and a podcast produced by our current Resident Podcasters. These are intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation. 

If you only have time to read one article this week, it should be this one.

Implementation of multiparametric magnetic resonance imaging technology for evaluation of patients with suspicion for prostate cancer in the clinical practice setting

Paras H. Shah*, Vinay R. Patel, Daniel M. Moreira, Arvin K. George§, Manaf Alom*, Zachary Kozel, Vidhu Joshi*, Eran Ben-Levi**, Robert Villani**, Oksana Yaskiv††Louis R. Kavoussi, Manish Vira, Carl O. Olsson‡‡ and Ardeshir R. Rastinehad

 

*Department of Urology, Mayo Clinic, Rochester, MN, Department of Urology, Icahn Smith Institute for Urology, Northwell Health, New York, NY, Department of Urology, University of Illinois at Chicago, Chicago, IL, §Department of Urology, University of Michigan, Ann Arbor, MI, Department of Urology, Smith Institute for Urology, Northwell Health, **Department of Radiology, Hofstra Northwell School of Medicine, ††Department of Pathology, Hofstra Northwell School of Medicine, New Hyde Park, and ‡‡Integrated Medical Professionals, Melville, NY, USA

 

Abstract

Objectives

To investigate the impact of implementing magnetic resonance imaging (MRI) and ultrasonography fusion technology on biopsy and prostate cancer (PCa) detection rates in men presenting with clinical suspicion for PCa in the clinical practice setting.

Patients and Methods

We performed a review of 1 808 consecutive men referred for elevated prostate‐specific antigen (PSA) level between 2011 and 2014. The study population was divided into two groups based on whether MRI was used as a risk stratification tool. Univariable and multivariable analyses of biopsy rates and overall and clinically significant PCa detection rates between groups were performed.

Results

The MRI and PSA‐only groups consisted of 1 020 and 788 patients, respectively. A total of 465 patients (45.6%) in the MRI group and 442 (56.1%) in the PSA‐only group underwent biopsy, corresponding to an 18.7% decrease in the proportion of patients receiving biopsy in the MRI group (P < 0.001). Overall PCa (56.8% vs 40.7%; P < 0.001) and clinically significant PCa detection (47.3% vs 31.0%; P < 0.001) was significantly higher in the MRI vs the PSA‐only group. In logistic regression analyses, the odds of overall PCa detection (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.29–2.35; P < 0.001) and clinically significant PCa detection (OR 2.04, 95% CI 1.48–2.80; P < 0.001) were higher in the MRI than in the PSA‐only group after adjusting for clinically relevant PCa variables.

Conclusion

Among men presenting with clinical suspicion for PCa, addition of MRI increases detection of clinically significant cancers while reducing prostate biopsy rates when implemented in a clinical practice setting.

 

Editorial: Multiparametric MRI for prostate cancer detection: do clinical trial findings reflect real‐world practice?

‘First, do no harm’; with this in mind, researchers in urology strive to minimize the burden of overdiagnosis and overtreatment of prostate cancer. A promising tool in this arena is multiparametric (mp)MRI, which has been shown in a large‐scale randomized clinical trial to enhance the ability of prostate biopsy to detect clinically significant prostate cancer [1]. The extent to which findings from an idealized trial protocol extend to ‘real‐world’ clinical practice, however, remains largely unknown.

In this issue of BJUI, Shah et al. [2] aimed to fill this knowledge gap by investigating the impact of mpMRI‐guided biopsy on the detection rates of clinically significant prostate cancer in two large academic centres. The authors studied men with an elevated PSA presenting over a 3‐year span (2011–2014); 1020 men underwent mpMRI and 788 did not. Those in the MRI group had higher detection rates of both overall and clinically significant prostate cancer, defined as any Gleason score ≥7 on fusion or standard 12‐core TRUS biopsies, Gleason 6 with a lesion volume >0.5 cm3 volume on MRI, or Gleason 6 with >2 cores positive and/or >50% of any core involved with cancer on biopsy according to Epstein’s criteria, as well as a lower detection rate of clinically insignificant cancer.

The study provides timely implications for both patients and physicians, providing further insight into how findings from clinical trials [1,3] compare with real‐life practice. In fairness, the bulk of patients and clinicians do not follow strict study protocols for both decision‐making and interpretation of results, but rather assess very individual situations. A recent study by Bukavina et al. [4] showed that urologists and radiation oncologists largely perceive mpMRI guidance for targeted biopsies as valuable tools to improve prostate cancer stratification, but only a quarter of respondents reported implementation into their own clinical practice. This underlines some of the challenges of widespread implementation of mpMRI despite strong belief in its value.

Another strength of the study by Shah et al. is the exclusion of men who underwent mpMRI after negative biopsy in the PSA‐only group. This allows the isolation of the impact of mpMRI on downstream biopsy outcomes. A previous study that investigated targeted vs non‐targeted biopsies enrolled a cohort of men who all underwent mpMRI [5], which precludes any assessment of how mpMRI may impact the detection of clinically significant prostate cancer. Shah et al. [2] also astutely tracked detection rates of clinically significant and insignificant prostate cancer. Since the process of diagnosing prostate cancer is not without morbidity, it is crucial to understand the extent to which mpMRI can prevent the diagnosis of clinically indolent cancers.

Important questions regarding the challenges of widespread implementation of mpMRI for prostate cancer detection remain unanswered by the study of Shah et al. The study participants were gathered from large academic centres with readily available equipment, infrastructure and physician expertise to maximize favourable detection outcomes; however, these results may not be representative of the community setting. Additionally, >20% of men who did not undergo mpMRI did not do so because of a lack of insurance approval. This may reflect socio‐economic differences between the groups and also relates to the high costs of mpMRI that make routine implementation difficult [6]. Lastly, the presented findings mostly apply to positive mpMRI scans; the number of underdiagnosed men with negative scans may only be speculated upon, given the lack of follow‐up data in this population. It remains fundamentally important to improve the management of men with elevated PSA levels and negative findings on MRI.

Nonetheless, the present study demonstrates that research findings find their way into clinical practice. In essence, we are doing well, but we can do better.

by Marieke J. Krimphove, Sean A. Fletcher and Quoc‐Dien Trinh

 

References

  1. Kasivisvanathan V, Rannikko AS, Borghi M et al. MRI‐targeted or standard biopsy for prostate‐cancer diagnosis. N Engl J Med 2018378: 1767–77
  2. Shah PH, Patel VR, Moreira DM et al. Implementation of multiparametric magnetic resonance imaging technology for evaluation of patients with suspicion for prostate cancer in the clinical practice setting. BJU Int 2019123: 239–45
  3. Ahmed HU, El‐Shater Bosaily A, Brown LC et al. Diagnostic accuracy of multi‐parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet 2017389: 815–22
  4. Bukavina L, Tilburt JC, Konety B et al. Perceptions of prostate MRI and fusion biopsy of radiation oncologists and urologists for patients diagnosed with prostate cancer: results from a national survey. Eur Urol Focus 2018; [Epub ahead of print]
  5. Pokorny MR, de Rooij M, Duncan E et al. Prospective study of diagnostic accuracy comparing prostate cancer detection by transrectal ultrasound–guided biopsy versus magnetic resonance (MR) imaging with subsequent MR‐guided biopsy in men without previous prostate biopsies. Eur Urol 201466: 22–9
  6. Kim SJ, Vickers AJ, Hu JC. Challenges in adopting level 1 evidence for multiparametric magnetic resonance imaging as a biomarker for prostate cancer screening. JAMA Oncol 2018; [Epub ahead of print]

 

Article of the Week: Cost‐effectiveness of MRI and targeted fusion biopsy for early detection of prostate cancer

Every Week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Cost‐effectiveness of magnetic resonance imaging and targeted fusion biopsy for early detection of prostate cancer

Christine L. Barnett* , Matthew S. Davenport, Jeffrey S. Montgomery, John T. WeiJames E. Montie‡ and Brian T. Denton*

 

*Departments of Industrial and Operations Engineering, Radiology, and Urology, University of Michigan, Ann Arbor, MI, USA

 

Objective

To determine how best to use magnetic resonance imaging (MRI) and targeted MRI/ultrasonography fusion biopsy for early detection of prostate cancer (PCa) in men with elevated prostate‐specific antigen (PSA) concentrations and whether it can be cost‐effective.

Methods

A Markov model of PCa onset and progression was developed to estimate the health and economic consequences of PCa screening with MRI. Patients underwent PSA screening from ages 55 to 69 years. Patients with elevated PSA concentrations (>4 ng/mL) underwent MRI, followed by targeted fusion or combined (standard + targeted fusion) biopsy on positive MRI, and standard or no biopsy on negative MRI. Prostate Imaging Reporting and Data System (PI‐RADS) score on MRI was used to determine biopsy decisions. Deaths averted, quality‐adjusted life‐years (QALYs), cost and incremental cost‐effectiveness ratio (ICER) were estimated for each strategy.


Results

With a negative MRI, standard biopsy was more expensive and had lower QALYs than performing no biopsy. The optimum screening strategy (ICER $23 483/QALY) recommended combined biopsy for patients with PI‐RADS score ≥3 and no biopsy for patients with PI‐RADS score <3, and reduced the number of screening biopsies by 15%. Threshold analysis suggests MRI continues to be cost‐effective when the sensitivity and specificity of MRI and combined biopsy are simultaneously reduced by 19 percentage points.

Conclusions

Our analysis suggests MRI followed by targeted MRI/ultrasonography fusion biopsy can be a cost‐effective approach to the early detection of PCa.

Editorial: MRI with targeted fusion biopsy: is the time now?

The current standard of performing TRUS‐guided systematic biopsy in men with a PSA of 4–10 ng/mL results in a considerable number of unnecessary prostate biopsies and overtreatment of clinically indolent disease, both of which are costly from the patient and healthcare system perspectives [1]. Two recent studies document that incorporating multiparametric (mp)MRI into prostate cancer screening has the potential to reduce overdiagnosis and overtreatment. Ahmed et al. [2] performed mpMRI followed by TRUS biopsy and template prostate mapping biopsy in 576 men with a PSA level of 4–14 ng/mL or an abnormal DRE. They found that using mpMRI to triage men would result in 27% fewer men undergoing biopsy while diagnosing 5% fewer clinically insignificant cancers. Furthermore, if subsequent TRUS biopsies were directed by mpMRI findings, 18% more cases of clinically significant cancer might be detected compared with traditional screening biopsies. Using a similar randomized study design, Kasivisvanathan et al. [3] found the use of mpMRI for screening reduced the biopsy rate by 28%, while lowering the rate of clinically insignificant cancer by 13% and improving the detection rate of clinically significant cancer by 12% [3]. While the addition of mpMRI to the screening armamentarium clearly provides clinical value, it also adds considerable increased costs, begging the question: is it worth it?

In the current issue of BJUI, Barnett et al. [1] evaluated the cost‐effectiveness of prostate MRI in a screening setting in order to determine whether MRI may be able to mitigate prostate biopsies in biopsy‐naïve men with a negative imaging study. They found that, when using the generally accepted threshold of $100 000/quality‐adjusted life year (QALY), the most cost‐efficient strategy consisted of obtaining prostate MRI in men with PSA >4 mg/mL. This was followed by either systematic and targeted fusion biopsy if the MRI showed a Prostate Imaging Reporting and Data System (PI‐RADS) score ≥3 lesion or continued observation if the MRI did not show a PI‐RADS score ≥3 lesion. Altogether, this strategy resulted in 5.9 prostate cancer deaths averted, 60.7 QALYs gained, and 72.6 life‐years gained for every 1000 patients screened. The number‐needed‐to‐treat to prevent one prostate cancer death with this approach was 169.

While the results are informative, the reader should interpret the study’s findings carefully as there is not agreement among policy makers on what is the optimal incremental willingness‐to‐pay threshold to determine what is truly cost‐effective. Furthermore, this study does not address the potential negative impact that detection of clinically insignificant prostate cancer may have on health‐state utilities and quality of life. Barnett et al. also predominantly obtained costs from Medicare data, but as previously reported, these costs are often rough estimates that are derived more from revenue or reimbursement than from the true cost of treating the disease process. The cost‐effectiveness estimates presented in this report, therefore, will probably vary from country to country. To examine the true cost, Laviana et al. [4] previously explored the cost of prostate MRI using time‐driven activity‐based costing and found the cost of MRI and mpMRI/TRUS to be $670 and $1,072 US dollars, respectively. These are significantly cheaper than the Medicare reported costs of $964.21 and $3,019.35 for MRI and mpMRI/TRUS, respectively. This implies that MRI and targeted biopsy may actually be even more cost‐effective than reported in the present study.

We must remember that, while the present study shows that MRI in prostate cancer screening may be cost‐effective, the base case population only included men with a PSA >4 mg/mL. This study does not address the cost‐effectiveness of a screening MRI in the larger population of all men at risk of prostate cancer, although previous data by Nam et al. [5] suggest MRI may be a potentially better primary screening tool than PSA. Of course, population‐wide prostate MRI screening would result in greatly increased upfront costs and, as such, the strategy would first need to be proven cost‐effective before MRI could replace PSA as the front‐line test in prostate cancer screening.

In conclusion, Burnett et al. elegantly demonstrate that an upfront MRI, in men with a PSA of >4 ng/mL, may ultimately be a cost‐effective approach depending on your willingness‐to‐pay threshold. Policymakers and payers worldwide should recognize that prostate MRI is here to stay and should be made more widely available to those with a PSA >4 ng/mL who are at risk of prostate cancer.

Aaron A. Laviana* and David F. Penson*
*Department of Urological Surgery, Vanderbilt University, and VA Tennessee Valley Geriatric Research, Education and Clinical Centre, Nashville, TN, USA

 

References
  1. Barnett C, Davenport M, Montgomery J et al. Cost‐effectiveness of magnetic resonance imaging and targeted fusion biopsy for early detection of prostate cancer. BJU Int 2018122: 50–8
  2. Ahmed HU, El‐Shater BA, Brown LC et al. Diagnostic accuracy of multi‐parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet 2017389: 815–22
  3. Kasivisvanathan V, Rannikko AS, Borghi M et al. MRI‐targeted or standard biopsy for prostate‐cancer diagnosis. N Engl J Med 2018; 378: 1767-77
  4. Laviana AA, Ilg AM, Veruttipong D et al. Utilizing time‐driven activity‐based costing to understand the short‐ and long‐term costs of treating localized, low‐risk prostate cancer. Cancer 2016122: 447–55
  5. Nam RK, Wallis CJD, Stojcic‐Bendavid J et al. A pilot study to evaluate the role of magnetic resonance imaging for prostate cancer screening in the general population. J Urol 2016192: 361–6

 

Article of the Month: MRI supported transperineal prostate biopsy

Every Month, the Editor-in-Chief selects an Article of the Month from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Multicentre evaluation of magnetic resonance imaging supported transperineal prostate biopsy in biopsy‐naïve men with suspicion of prostate cancer

 

Nienke L. Hansen*1, Tristan Barrett*, Claudia Kesch, Lana Pepdjonovic§, David Bonekamp, Richard OSullivan**, Florian Distler, Anne Warren*††, Christina Samel‡‡Boris Hadaschik2, Jeremy Grummet§ and Christof Kastner*§§
*CamPARI Clinic, Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, UK, Department of Urology, University Hospital Heidelberg, Heidelberg, Germany, §Australian Urology Associates and Department of Surgery, Central Clinical School, Monash University, Melbourne, Vic., Australia, Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, **Healthcare Imaging and Monash University, Melbourne, Vic., Australia, ††Department of Pathology, Addenbrookes Hospital and University of Cambridge, Cambridge, UK, ‡‡Institute of Medical Statistics, Informatics and Epidemiology, University Hospital Cologne, Cologne, Germany, and §§Department of Urology, Addenbrookes Hospital and University of Cambridge, Cambridge, UK 

 

Current addresses: 1Department of Diagnostic and Interventional Radiology University Hospital Cologne Cologne Germany, 2Department of Urology University Hospital Essen Essen Germany. 

 

B.H., J.G., and C.K. contributed equally to this work.

 

Abstract

Objectives

To analyse the detection rates of primary magnetic resonance imaging (MRI)‐fusion transperineal prostate biopsy using combined targeted and systematic core distribution in three tertiary referral centres.

Patients and Methods

In this multicentre, prospective outcome study, 807 consecutive biopsy‐naïve patients underwent MRI‐guided transperineal prostate biopsy, as the first diagnostic intervention, between 10/2012 and 05/2016. MRI was reported following the Prostate Imaging‐Reporting and Data System (PI‐RADS) criteria. In all, 236 patients had 18–24 systematic transperineal biopsies only, and 571 patients underwent additional targeted biopsies either by MRI‐fusion or cognitive targeting if PI‐RADS ≥3 lesions were present. Detection rates for any and Gleason score 7–10 cancer in targeted and overall biopsy were calculated and predictive values were calculated for different PI‐RADS and PSA density (PSAD) groups.

Results

Cancer was detected in 68% of the patients (546/807) and Gleason score 7–10 cancer in 49% (392/807). The negative predictive value of 236 PI‐RADS 1–2 MRI in combination with PSAD of <0.1 ng/mL/mL for Gleason score 7–10 was 0.91 (95% confidence interval ± 0.07, 8% of study population). In 418 patients with PI‐RADS 4–5 lesions using targeted plus systematic biopsies, the cancer detection rate of Gleason score 7–10 was significantly higher at 71% vs 59% and 61% with either approach alone (P < 0.001). For 153 PI‐RADS 3 lesions, the detection rate was 31% with no significant difference to systematic biopsies with 27% (P > 0.05). Limitations include variability of multiparametric MRI (mpMRI) reading and Gleason grading.

Conclusion

MRI‐based transperineal biopsy performed at high‐volume tertiary care centres with a significant experience of prostate mpMRI and image‐guided targeted biopsies yielded high detection rates of Gleason score 7–10 cancer. Prostate biopsies may not be needed for men with low PSAD and an unsuspicious MRI. In patients with high probability lesions, combined targeted and systematic biopsies are recommended.

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