Objective: To study the effectiveness of diffusion weighted magnetic resonance imaging(DW-MRI) without the use an endo-rectal coil on detecting prostate zones with ma-lignancy prior to prostate biopsies and to see whether the method can serve as a guide pri-or to transrectal ultrasound guided prostate bi-opsies.
Materials and Methods: Between July 2010-August 2011, 34 patients with an indica-tion for a prostate biopsy with no positive fin-dings on digital rectal examination underwent DW-MRI. The lowest limit for PSA was 2,5ng/ml. The zones of biopsy were marked as: “a(1-6)” for the right side and “b(1-6)” for the left side. 2 biopsy cores were taken from every zone and the specimens for every zone were sent to pathology separately in 12 tubes. Pathologic findings were matched with the prebiopsy DW-MRI findings for a possible correlation.
Results: The mean PSA value for patients with prostate cancer (PCa) was 7,0 ± 2,6. PCa was detected in 9/34 patients(26%). Out of the 9 patients with a malignant biopsy, 6 had po-sitive correlation in terms of Pca findings on DW-MRI (67%), whereas 8/9(88,8%) patients were only organ specific. Positive predictive va-lue was 8/20(40%) and negative predictive value was 13/14(92,8%) with an overall predictive va-lue of 21/34(61,8%).
Conclusion: DW-MRI without endorectal coil needs more de-velopment before acting as a guide for TRUSG guided prostate bi-opsies. We believe that, in order to find the ideal method to diagno-se the tumors most efficiently and with the least complication rates, more expanded studies with larger series have to be done.
Key Words: Prostate cancer, diagnosis, radiology, MRI
Abstract
Objective: To study the effectiveness of diffusion weighted magnetic resonance imaging(DW-MRI) without the use an endo-rectal coil on detecting prostate zones with ma-lignancy prior to prostate biopsies and to see whether the method can serve as a guide pri-or to transrectal ultrasound guided prostate bi-opsies.
Materials and Methods: Between July 2010-August 2011, 34 patients with an indica-tion for a prostate biopsy with no positive fin-dings on digital rectal examination underwent DW-MRI. The lowest limit for PSA was 2,5ng/ml. The zones of biopsy were marked as: “a(1-6)” for the right side and “b(1-6)” for the left side. 2 biopsy cores were taken from every zone and the specimens for every zone were sent to pathology separately in 12 tubes. Pathologic findings were matched with the prebiopsy DW-MRI findings for a possible correlation.
Results: The mean PSA value for patients with prostate cancer (PCa) was 7,0 ± 2,6. PCa was detected in 9/34 patients(26%). Out of the 9 patients with a malignant biopsy, 6 had po-sitive correlation in terms of Pca findings on DW-MRI (67%), whereas 8/9(88,8%) patients were only organ specific. Positive predictive va-lue was 8/20(40%) and negative predictive value was 13/14(92,8%) with an overall predictive va-lue of 21/34(61,8%).
Conclusion: DW-MRI without endorectal coil needs more de-velopment before acting as a guide for TRUSG guided prostate bi-opsies. We believe that, in order to find the ideal method to diagno-se the tumors most efficiently and with the least complication rates, more expanded studies with larger series have to be done.
Key Words: Prostate cancer, diagnosis, radiology, MRI