- Email: [email protected]
Will all patients with suspicion of prostate cancer undergo multiparametric MRI before biopsy in the future?
Diagnostic and Interventional Imaging (2016) 97, 389—391
EDITORIAL
Will all patients with suspicion of prostate cancer undergo multiparametric MRI before biopsy in the future?
After an initial period of skepticism [1], urologists are increasingly ordering multiparametric magnetic resonance imaging (mpMRI) before prostate biopsy. Although comparisons to prostatectomy specimens have shown, without any doubt, that mpMRI can detect aggressive prostate cancer (PCa) with excellent sensitivity [2—4], its diagnostic yield as compared to systematic biopsies must be evaluated with care to avoid over-prescription and unnecessary health costs. Current evidence suggests that mpMRI is useful to guide prostate biopsy, but its added value differs from one population of patients to another.
Patients with no history of PCa A recent meta-analysis showed that targeted biopsies based on mpMRI findings (TBx) had a higher detection rate of clinically significant PCa compared to systematic biopsy (sensitivity of 0.91 [95% confidence interval (CI): 0.87—0.94] versus 0.76 [95% CI: 0.64—0.84]) and a lower rate of detection of insignificant PCa (sensitivity of 0.44 [95% CI: 0.26—0.64] versus 0.83 [95% CI: 0.77—0.87]) (5). However, the added value of TBx in detecting clinically significant PCa was marked in the subgroup of patients with previous negative biopsies (relative sensitivity of 1.54 [95% CI: 1.05—2.57]) but not in the subgroup of biopsy-naïve patients (relative sensitivity of 1.10 [95% CI: 1.00—1.22]). There was a trend for TBx to detect less clinically non-significant cancers in both subgroups (relative sensitivity of 0.82 [95% CI: 0.03—21.4] and 0.51 [95% CI: 0.25—1.04] respectively) but the difference was not significant. Another systematic review also concluded that Tbx improved detection rates in the repeat biopsy setting, but not at initial biopsy [6]. These results can be explained by the fact that the proportion of tumors in locations easily missed by systematic biopsies (e.g., anterior tumors) is higher in the repeat biopsy setting. The impact of pre-biopsy mpMRI is therefore easier to demonstrate in this population. As a result, the 2016 European Association of Urology guidelines on prostate cancer recommend obtaining a mpMRI before repeat biopsy [7]. The precise role of mpMRI in biopsy-naïve patients remains to be defined. Two prospective randomized trials gave contradictory results [8,9]. Several multicentric controlled studies are currently ongoing in this population. http://dx.doi.org/10.1016/j.diii.2016.03.007 2211-5684/© 2016 Published by Elsevier Masson SAS on behalf of the Éditions françaises de radiologie.
390
Editorial
Active surveillance
Disclosure of interest
MpMRI can significantly predict the presence of aggressive cancers in patients suitable for active surveillance (AS) but treated by radical prostatectomy [10]. At the start of AS, a positive mpMRI significantly predicts the presence of aggressive cancer at repeat biopsy [5]. However, there is a need for well-designed prospective multicentric studies to definitively assess the added value of TBx as compared to systematic biopsy at the start of AS. The potential role of mpMRI during AS remains unclear. There are currently no validated radiological criteria of progression that could to trigger follow-up biopsy.
The author has not supplied his declaration of competing interest.
Biochemical recurrence In patients with biochemical recurrence, the role of mpMRI will probably depend upon the initial treatment. There is increasing evidence that mpMRI can accurately detect local recurrences after radiotherapy [11—13], as shown by the study of Alonzo et al. [14] published in this issue of Diagnostic and Interventional Imaging. Local recurrence after radiotherapy is a serious condition associated with a substantial risk of death [15]. It is mandatory to detect it early, at least in patients fit enough for salvage therapy. MpMRI should improve this early detection and be recommended before prostate biopsy in a near future. The role of mpMRI in the detection of local relapse after radical prostatectomy is less clear. To be useful, mpMRI should detect local recurrences when the prostate specific antigen (PSA) value is < 0.5 ng/mL, so that a boost of salvage radiotherapy could be performed on foci of recurrence. Some studies suggest it might be the case [16,17], but robust data is lacking.
The issue of the negative predictive value of mpMRI In theory, mpMRI could be used in two different ways before biopsy: either to trigger TBx in addition to systematic biopsy, or to select patients who should undergo biopsy. In this latter case, mpMRI could help reduce the number of negative and unnecessary biopsies. However, to act as a triage test, mpMRI must show excellent negative predictive value for aggressive cancer. This issue is more complex than it appears since the negative predictive value depends on the prevalence of the disease in the population. Here again, it will be necessary to carefully assess each specific population of patients that may undergo mpMRI. In conclusion, there is an urgent need to better define the populations in which mpMRI positive findings may help sensitize the detection of aggressive cancer at biopsy and, even more importantly, the populations in which a negative mpMRI (alone or in combination with biochemical and clinical data) may avoid unnecessary biopsy. There is no doubt that the next few years will be pivotal in answering these questions.
References [1] Heidenreich A. Consensus criteria for the use of magnetic resonance imaging in the diagnosis and staging of prostate cancer: not ready for routine use. Eur Urol 2011;59:495—7. [2] Bratan F, Niaf E, Melodelima C, et al. Influence of imaging and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study. Eur Radiol 2013;23:2019—29. [3] Turkbey B, Mani H, Shah V, et al. Multiparametric 3T prostate magnetic resonance imaging to detect cancer: histopathological correlation using prostatectomy specimens processed in customized magnetic resonance imaging based molds. J Urol 2011;186:1818—24. [4] Barral M, Cornud F, Neuzillet Y, et al. Characteristics of undetected prostate cancer on diffusion-weighted MR Imaging at 3-Tesla with a b-value of 2000s/mm(2): imaging-pathologic correlation. Diagn Interv Imaging 2015;96:923—9. [5] Schoots IG, Petrides N, Giganti F, et al. Magnetic resonance imaging in active surveillance of prostate cancer: a systematic review. Eur Urol 2015;67:627—36. [6] van Hove A, Savoie PH, Maurin C, et al. Comparison of image-guided targeted biopsies versus systematic randomized biopsies in the detection of prostate cancer: a systematic literature review of well-designed studies. World J Urol 2014;32:847—58. [7] Mottet N, Bellmunt J, Briers E, et al. Guidelines on prostate cancer. http://uroweb.org/wp-content/uploads/09-ProstateCancer LR.pdf. [Update March 2015; last accessed on March 2016]. [8] Panebianco V, Barchetti F, Sciarra A, et al. Multiparametric magnetic resonance imaging vs. standard care in men being evaluated for prostate cancer: a randomized study. Urol Oncol 2015;33:17 [e1—7]. [9] Baco E, Rud E, Eri LM, et al. A Randomized controlled trial to assess and compare the outcomes of two-core prostate biopsy guided by fused magnetic resonance and transrectal ultrasound images and traditional 12-core systematic biopsy. Eur Urol 2016;69:149—56. [10] Turkbey B, Mani H, Aras O, et al. Prostate cancer: can multiparametric MR imaging help identify patients who are candidates for active surveillance? Radiology 2013;268: 144—52. [11] Rouviere O, Vitry T, Lyonnet D. Imaging of prostate cancer local recurrences: why and how? Eur Radiol 2010;20: 1254—66. [12] Donati OF, Jung SI, Vargas HA, et al. Multiparametric prostate MR imaging with T2-weighted, diffusionweighted, and dynamic contrast-enhanced sequences: are all pulse sequences necessary to detect locally recurrent prostate cancer after radiation therapy? Radiology 2013;268: 440—50. [13] Abd-Alazeez M, Ramachandran N, Dikaios N, et al. Multiparametric MRI for detection of radio-recurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images. Prostate Cancer Prostatic Dis 2015;18:128—36. [14] Alonzo F, Melodelima C, Bratan F, et al. Detection of locally radio-recurrent prostate cancer at multiparametric MRI: can
Editorial dynamic contrast-enhanced imaging be omitted? Diagn Interv Imaging 2016;97:431—9. [15] Zelefsky MJ, Reuter VE, Fuks Z, Scardino P, Shippy A. Influence of local tumor control on distant metastases and cancer related mortality after external beam radiotherapy for prostate cancer. J Urol 2008;179:1368—73. [16] Liauw SL, Pitroda SP, Eggener SE, et al. Evaluation of the prostate bed for local recurrence after radical prostatectomy using endorectal magnetic resonance imaging. Int J Radiat Oncol Biol Phys 2013;85:378—84. [17] Linder BJ, Kawashima A, Woodrum DA, et al. Early localization of recurrent prostate cancer after prostatectomy by endorectal coil magnetic resonance imaging. Can J Urol 2014;21: 7283—9.
391 O. Rouvière a,b,c,d,∗ a
Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Hôpital Édouard-Herriot, 5, place d’Arsonval, 69437 Lyon, France b Université de Lyon, 69003 Lyon, France c Université Lyon 1, Faculté de médecine Lyon Est, 69003 Lyon, France d Inserm, U1032, LabTau, 69003 Lyon, France ∗ Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Hôpital Édouard-Herriot, 5, place d’Arsonval, 69437 Lyon, France.
E-mail address: [email protected]
EDITORIAL
Will all patients with suspicion of prostate cancer undergo multiparametric MRI before biopsy in the future?
After an initial period of skepticism [1], urologists are increasingly ordering multiparametric magnetic resonance imaging (mpMRI) before prostate biopsy. Although comparisons to prostatectomy specimens have shown, without any doubt, that mpMRI can detect aggressive prostate cancer (PCa) with excellent sensitivity [2—4], its diagnostic yield as compared to systematic biopsies must be evaluated with care to avoid over-prescription and unnecessary health costs. Current evidence suggests that mpMRI is useful to guide prostate biopsy, but its added value differs from one population of patients to another.
Patients with no history of PCa A recent meta-analysis showed that targeted biopsies based on mpMRI findings (TBx) had a higher detection rate of clinically significant PCa compared to systematic biopsy (sensitivity of 0.91 [95% confidence interval (CI): 0.87—0.94] versus 0.76 [95% CI: 0.64—0.84]) and a lower rate of detection of insignificant PCa (sensitivity of 0.44 [95% CI: 0.26—0.64] versus 0.83 [95% CI: 0.77—0.87]) (5). However, the added value of TBx in detecting clinically significant PCa was marked in the subgroup of patients with previous negative biopsies (relative sensitivity of 1.54 [95% CI: 1.05—2.57]) but not in the subgroup of biopsy-naïve patients (relative sensitivity of 1.10 [95% CI: 1.00—1.22]). There was a trend for TBx to detect less clinically non-significant cancers in both subgroups (relative sensitivity of 0.82 [95% CI: 0.03—21.4] and 0.51 [95% CI: 0.25—1.04] respectively) but the difference was not significant. Another systematic review also concluded that Tbx improved detection rates in the repeat biopsy setting, but not at initial biopsy [6]. These results can be explained by the fact that the proportion of tumors in locations easily missed by systematic biopsies (e.g., anterior tumors) is higher in the repeat biopsy setting. The impact of pre-biopsy mpMRI is therefore easier to demonstrate in this population. As a result, the 2016 European Association of Urology guidelines on prostate cancer recommend obtaining a mpMRI before repeat biopsy [7]. The precise role of mpMRI in biopsy-naïve patients remains to be defined. Two prospective randomized trials gave contradictory results [8,9]. Several multicentric controlled studies are currently ongoing in this population. http://dx.doi.org/10.1016/j.diii.2016.03.007 2211-5684/© 2016 Published by Elsevier Masson SAS on behalf of the Éditions françaises de radiologie.
390
Editorial
Active surveillance
Disclosure of interest
MpMRI can significantly predict the presence of aggressive cancers in patients suitable for active surveillance (AS) but treated by radical prostatectomy [10]. At the start of AS, a positive mpMRI significantly predicts the presence of aggressive cancer at repeat biopsy [5]. However, there is a need for well-designed prospective multicentric studies to definitively assess the added value of TBx as compared to systematic biopsy at the start of AS. The potential role of mpMRI during AS remains unclear. There are currently no validated radiological criteria of progression that could to trigger follow-up biopsy.
The author has not supplied his declaration of competing interest.
Biochemical recurrence In patients with biochemical recurrence, the role of mpMRI will probably depend upon the initial treatment. There is increasing evidence that mpMRI can accurately detect local recurrences after radiotherapy [11—13], as shown by the study of Alonzo et al. [14] published in this issue of Diagnostic and Interventional Imaging. Local recurrence after radiotherapy is a serious condition associated with a substantial risk of death [15]. It is mandatory to detect it early, at least in patients fit enough for salvage therapy. MpMRI should improve this early detection and be recommended before prostate biopsy in a near future. The role of mpMRI in the detection of local relapse after radical prostatectomy is less clear. To be useful, mpMRI should detect local recurrences when the prostate specific antigen (PSA) value is < 0.5 ng/mL, so that a boost of salvage radiotherapy could be performed on foci of recurrence. Some studies suggest it might be the case [16,17], but robust data is lacking.
The issue of the negative predictive value of mpMRI In theory, mpMRI could be used in two different ways before biopsy: either to trigger TBx in addition to systematic biopsy, or to select patients who should undergo biopsy. In this latter case, mpMRI could help reduce the number of negative and unnecessary biopsies. However, to act as a triage test, mpMRI must show excellent negative predictive value for aggressive cancer. This issue is more complex than it appears since the negative predictive value depends on the prevalence of the disease in the population. Here again, it will be necessary to carefully assess each specific population of patients that may undergo mpMRI. In conclusion, there is an urgent need to better define the populations in which mpMRI positive findings may help sensitize the detection of aggressive cancer at biopsy and, even more importantly, the populations in which a negative mpMRI (alone or in combination with biochemical and clinical data) may avoid unnecessary biopsy. There is no doubt that the next few years will be pivotal in answering these questions.
References [1] Heidenreich A. Consensus criteria for the use of magnetic resonance imaging in the diagnosis and staging of prostate cancer: not ready for routine use. Eur Urol 2011;59:495—7. [2] Bratan F, Niaf E, Melodelima C, et al. Influence of imaging and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study. Eur Radiol 2013;23:2019—29. [3] Turkbey B, Mani H, Shah V, et al. Multiparametric 3T prostate magnetic resonance imaging to detect cancer: histopathological correlation using prostatectomy specimens processed in customized magnetic resonance imaging based molds. J Urol 2011;186:1818—24. [4] Barral M, Cornud F, Neuzillet Y, et al. Characteristics of undetected prostate cancer on diffusion-weighted MR Imaging at 3-Tesla with a b-value of 2000s/mm(2): imaging-pathologic correlation. Diagn Interv Imaging 2015;96:923—9. [5] Schoots IG, Petrides N, Giganti F, et al. Magnetic resonance imaging in active surveillance of prostate cancer: a systematic review. Eur Urol 2015;67:627—36. [6] van Hove A, Savoie PH, Maurin C, et al. Comparison of image-guided targeted biopsies versus systematic randomized biopsies in the detection of prostate cancer: a systematic literature review of well-designed studies. World J Urol 2014;32:847—58. [7] Mottet N, Bellmunt J, Briers E, et al. Guidelines on prostate cancer. http://uroweb.org/wp-content/uploads/09-ProstateCancer LR.pdf. [Update March 2015; last accessed on March 2016]. [8] Panebianco V, Barchetti F, Sciarra A, et al. Multiparametric magnetic resonance imaging vs. standard care in men being evaluated for prostate cancer: a randomized study. Urol Oncol 2015;33:17 [e1—7]. [9] Baco E, Rud E, Eri LM, et al. A Randomized controlled trial to assess and compare the outcomes of two-core prostate biopsy guided by fused magnetic resonance and transrectal ultrasound images and traditional 12-core systematic biopsy. Eur Urol 2016;69:149—56. [10] Turkbey B, Mani H, Aras O, et al. Prostate cancer: can multiparametric MR imaging help identify patients who are candidates for active surveillance? Radiology 2013;268: 144—52. [11] Rouviere O, Vitry T, Lyonnet D. Imaging of prostate cancer local recurrences: why and how? Eur Radiol 2010;20: 1254—66. [12] Donati OF, Jung SI, Vargas HA, et al. Multiparametric prostate MR imaging with T2-weighted, diffusionweighted, and dynamic contrast-enhanced sequences: are all pulse sequences necessary to detect locally recurrent prostate cancer after radiation therapy? Radiology 2013;268: 440—50. [13] Abd-Alazeez M, Ramachandran N, Dikaios N, et al. Multiparametric MRI for detection of radio-recurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images. Prostate Cancer Prostatic Dis 2015;18:128—36. [14] Alonzo F, Melodelima C, Bratan F, et al. Detection of locally radio-recurrent prostate cancer at multiparametric MRI: can
Editorial dynamic contrast-enhanced imaging be omitted? Diagn Interv Imaging 2016;97:431—9. [15] Zelefsky MJ, Reuter VE, Fuks Z, Scardino P, Shippy A. Influence of local tumor control on distant metastases and cancer related mortality after external beam radiotherapy for prostate cancer. J Urol 2008;179:1368—73. [16] Liauw SL, Pitroda SP, Eggener SE, et al. Evaluation of the prostate bed for local recurrence after radical prostatectomy using endorectal magnetic resonance imaging. Int J Radiat Oncol Biol Phys 2013;85:378—84. [17] Linder BJ, Kawashima A, Woodrum DA, et al. Early localization of recurrent prostate cancer after prostatectomy by endorectal coil magnetic resonance imaging. Can J Urol 2014;21: 7283—9.
391 O. Rouvière a,b,c,d,∗ a
Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Hôpital Édouard-Herriot, 5, place d’Arsonval, 69437 Lyon, France b Université de Lyon, 69003 Lyon, France c Université Lyon 1, Faculté de médecine Lyon Est, 69003 Lyon, France d Inserm, U1032, LabTau, 69003 Lyon, France ∗ Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Hôpital Édouard-Herriot, 5, place d’Arsonval, 69437 Lyon, France.
E-mail address: [email protected]