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Re: Transition Zone Prostate Cancer: Detection and Localization with 3-T Multiparametric MR Imaging
IMAGING
881
Imaging Re: Transition Zone Prostate Cancer: Detection and Localization with 3-T Multiparametric MR Imaging C. M. Hoeks, T. Hambrock, D. Yakar, C. A. Hulsbergen-van de Kaa, T. Feuth, J. A. Witjes, J. J. Fütterer and J. O. Barentsz Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Radiology 2013; 266: 207–217.
Abstract available at http://jurology.com/ Editorial Comment: This is a retrospective study comparing 3 T multiparametric magnetic resonance (MR) imaging and radical prostatectomy for transitional zone prostate cancer. On T2-weighted images the transition zone is often lumpy and heterogeneous secondary to benign prostatic hyperplasia, making prostate cancers difficult to discern. A larger, more geographic area of low signal intensity, ill defined margins and lenticular shape are features suggestive of transitional zone prostate cancer. A total of 28 patients with transitional zone cancer were selected and 35 patients with a peripheral zone cancer were included as controls. Patients with prior radiation therapy or prior transurethral prostatectomy were excluded from the study. MR consisted of T2, diffusion and dynamic contrast enhancement sequences. The radiologist scored the transition zone from 1 to 5, with 1 being definite absence of transitional zone cancer and 5 being definite presence of transitional zone cancer. The authors found that the overall accuracy in detection of Gleason grade 4 to 5 transitional zone prostate cancer was 79% for T2 weighting and 72% for T2 weighting plus diffusion, apparent diffusion coefficient and dynamic contrast enhancement. For patients with lower Gleason grade (2 to 3) the accuracy for T2-weighted imaging was 66%. When diffusion, apparent diffusion coefficient and dynamic contrast enhancement were added, the accuracy was decreased to 62%. The authors conclude that multiparametric MR did not add to the accuracy for detection of transitional zone tumors. One of the reasons why dynamic contrast enhancement may not provide additional benefit is due to the heterogeneous enhancement seen in benign prostatic hyperplasia. A few take home points about this study are that 1) radiologists need to be on the lookout for tumors in the transition zone, 2) T2-weighted images are the main sequence to identify these tumors and 3) dynamic contrast enhancement might not help. Cary Siegel, M.D.
881
Imaging Re: Transition Zone Prostate Cancer: Detection and Localization with 3-T Multiparametric MR Imaging C. M. Hoeks, T. Hambrock, D. Yakar, C. A. Hulsbergen-van de Kaa, T. Feuth, J. A. Witjes, J. J. Fütterer and J. O. Barentsz Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Radiology 2013; 266: 207–217.
Abstract available at http://jurology.com/ Editorial Comment: This is a retrospective study comparing 3 T multiparametric magnetic resonance (MR) imaging and radical prostatectomy for transitional zone prostate cancer. On T2-weighted images the transition zone is often lumpy and heterogeneous secondary to benign prostatic hyperplasia, making prostate cancers difficult to discern. A larger, more geographic area of low signal intensity, ill defined margins and lenticular shape are features suggestive of transitional zone prostate cancer. A total of 28 patients with transitional zone cancer were selected and 35 patients with a peripheral zone cancer were included as controls. Patients with prior radiation therapy or prior transurethral prostatectomy were excluded from the study. MR consisted of T2, diffusion and dynamic contrast enhancement sequences. The radiologist scored the transition zone from 1 to 5, with 1 being definite absence of transitional zone cancer and 5 being definite presence of transitional zone cancer. The authors found that the overall accuracy in detection of Gleason grade 4 to 5 transitional zone prostate cancer was 79% for T2 weighting and 72% for T2 weighting plus diffusion, apparent diffusion coefficient and dynamic contrast enhancement. For patients with lower Gleason grade (2 to 3) the accuracy for T2-weighted imaging was 66%. When diffusion, apparent diffusion coefficient and dynamic contrast enhancement were added, the accuracy was decreased to 62%. The authors conclude that multiparametric MR did not add to the accuracy for detection of transitional zone tumors. One of the reasons why dynamic contrast enhancement may not provide additional benefit is due to the heterogeneous enhancement seen in benign prostatic hyperplasia. A few take home points about this study are that 1) radiologists need to be on the lookout for tumors in the transition zone, 2) T2-weighted images are the main sequence to identify these tumors and 3) dynamic contrast enhancement might not help. Cary Siegel, M.D.