Mohammad Mehrmohammadi1, Azra Alizad2, Randall R Kinnick1, Brian J Davis3, Mostafa Fatemi1. 1. Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905. 2. Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905 and Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905. 3. Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905.
Abstract
PURPOSE: Effective permanent prostate brachytherapy (PPB) requires precise placement of radioactive seeds in and around the prostate. The impetus for this research is to examine a new ultrasound-based imaging modality, vibro-acoustography (VA), which may serve to provide a high rate of PPB seed detection while also effecting enhanced prostate imaging. The authors investigate the ability of VA, implemented on a clinical ultrasound (US) scanner and equipped with a quasi-2D (Q2D) array US transducer, to detect and localize PPB seeds in excised prostate specimens. METHODS: Nonradioactive brachytherapy seeds were implanted into four excised cadaver prostates. A clinical US scanner equipped with a Q2D array US transducer was customized to acquire both US and C-scan VA images at various depths. The VA images were then used to detect and localize the implanted seeds in prostate tissue. To validate the VA results, computed tomography (CT) images of the same tissue samples were obtained to serve as the reference by which to evaluate the performance of VA in PPB seed detection. RESULTS: The results indicate that VA is capable of accurately identifying the presence and distribution of PPB seeds with a high imaging contrast. Moreover, a large ratio of the PPB seeds implanted into prostate tissue samples could be detected through acquired VA images. Using CT-based seed identification as the standard, VA was capable of detecting 74%-92% of the implanted seeds. Additionally, the angular independency of VA in detecting PPB seeds was demonstrated through a well-controlled phantom experiment. CONCLUSIONS: Q2DVA detected a substantial portion of the seeds by using a 2D array US transducer in excised prostate tissue specimens. While VA has inherent advantages associated with conventional US imaging, it has the additional advantage of permitting detection of PPB seeds independent of their orientation. These results suggest the potential of VA as a method for PPB imaging that ultimately may allow US-based real-time intraoperative dosimetry.
PURPOSE: Effective permanent prostate brachytherapy (PPB) requires precise placement of radioactive seeds in and around the prostate. The impetus for this research is to examine a new ultrasound-based imaging modality, vibro-acoustography (VA), which may serve to provide a high rate of PPB seed detection while also effecting enhanced prostate imaging. The authors investigate the ability of VA, implemented on a clinical ultrasound (US) scanner and equipped with a quasi-2D (Q2D) array US transducer, to detect and localize PPB seeds in excised prostate specimens. METHODS: Nonradioactive brachytherapy seeds were implanted into four excised cadaver prostates. A clinical US scanner equipped with a Q2D array US transducer was customized to acquire both US and C-scan VA images at various depths. The VA images were then used to detect and localize the implanted seeds in prostate tissue. To validate the VA results, computed tomography (CT) images of the same tissue samples were obtained to serve as the reference by which to evaluate the performance of VA in PPB seed detection. RESULTS: The results indicate that VA is capable of accurately identifying the presence and distribution of PPB seeds with a high imaging contrast. Moreover, a large ratio of the PPB seeds implanted into prostate tissue samples could be detected through acquired VA images. Using CT-based seed identification as the standard, VA was capable of detecting 74%-92% of the implanted seeds. Additionally, the angular independency of VA in detecting PPB seeds was demonstrated through a well-controlled phantom experiment. CONCLUSIONS: Q2DVA detected a substantial portion of the seeds by using a 2D array US transducer in excised prostate tissue specimens. While VA has inherent advantages associated with conventional US imaging, it has the additional advantage of permitting detection of PPB seeds independent of their orientation. These results suggest the potential of VA as a method for PPB imaging that ultimately may allow US-based real-time intraoperative dosimetry.
Authors: Brian J Davis; Randall R Kinnick; Mostafa Fatemi; Eugene P Lief; Richard A Robb; James F Greenleaf Journal: Int J Radiat Oncol Biol Phys Date: 2003-11-15 Impact factor: 7.038
Authors: Glauber T Silva; Shigao Chen; Alejandro C Frery; James F Greenleaf; Mostafa Fatemi Journal: IEEE Trans Ultrason Ferroelectr Freq Control Date: 2005-11 Impact factor: 2.725
Authors: Azra Alizad; Mohammad Mehrmohammadi; Farid G Mitri; Brian J Davis; Thomas J Sebo; Lance A Mynderse; Randall R Kinnick; James F Greenleaf; Mostafa Fatemi Journal: Med Phys Date: 2013-02 Impact factor: 4.071
Authors: Brian J Davis; Eric M Horwitz; W Robert Lee; Juanita M Crook; Richard G Stock; Gregory S Merrick; Wayne M Butler; Peter D Grimm; Nelson N Stone; Louis Potters; Anthony L Zietman; Michael J Zelefsky Journal: Brachytherapy Date: 2012 Jan-Feb Impact factor: 2.362
Authors: Matthew W Urban; Carl Chalek; Bruno Haider; Kai E Thomenius; Mostafa Fatemi; Azra Alizad Journal: IEEE Trans Ultrason Ferroelectr Freq Control Date: 2013-03 Impact factor: 2.725