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Brian J Davis

Publications and source records attributed to Brian J Davis.

22 records · Page 2Linked to original sources
PubMedDate not supplied

3D visualization, analysis, and treatment of the prostate using trans-urethral ultrasound.

In the year 2000, it is estimated that over 20,000 men underwent transperineal interstitial permanent prostate brachytherapy (TIPPB) for treatment of prostate cancer. Trans-urethral ultrasound (TUUS) is a new interactive, real-time 3D imaging method that may be effective in therapy-guidance during and after TIPPB. TUUS provides higher resolution than trans-rectal ultrasound (TRUS). TUUS can be used to accurately localize radioactive seeds and therefore contribute to more accurate determination of radiation dose distribution throughout the tissue after the completion of the procedure, similar to information currently provided by expensive and offline CT scans. A TUUS catheter can be used to acquire 2D section images or 3D volume images for detailed analyses of the prostate and associated tissue. Initial development of TUUS imaging was carried out on an ultrasound-equivalent prostate phantom with cylindrical dummy radiation sources. This was followed by preliminary studies in animals and then in patients. Both CT and TRUS data were acquired in these studies for comparative purposes. Segmentation of the prostate capsule and radioactive seeds was carried out using several semi-automated 3D algorithms and image processing techniques. Presentation of the data to the clinician is provided by a variety of complementary 2D and 3D display methods. In comparison with the CT data, TUUS data provided both greater spatial resolution and better soft tissue differentiation. In comparison to the TRUS data, TUUS data provided greater resolution and better seed localization. Combining these advantages suggests the possibility of TUUS becoming the exclusive imaging method in prostate cancer brachytherapy.

Humans↗
PubMedDate not supplied

Prostate volume before and after permanent prostate brachytherapy in patients receiving neoadjuvant androgen suppression.

PURPOSE: Limited duration neoadjuvant cytoreductive hormonal therapy (NHT) is used before the definitive radiotherapeutic management of prostate cancer to decrease target volume size and/or to decrease urinary obstructive symptoms. The purpose of this study is to examine the effect of NHT on prostate volume before permanent prostate brachytherapy (PPB) and on prostatic edema after PPB. METHODS AND MATERIALS: Between May 1998 and February 2004, 408 patients underwent PPB at our institution and provided research authorization for the use of their records. Of these, 122 (30%) underwent NHT. Of the 122, 78 (64%) underwent transrectal ultrasound before the start of NHT. Patients undergoing PPB who received NHT were compared with a similar non-NHT group (N = 286). Detailed measurements of prostate volume were performed by transrectal ultrasound before and after NHT, if applicable. In addition, intraoperative preimplantation transrectal ultrasound and post-implantation transrectal ultrasound were also performed. Post-implantation computed tomography was per formed within 1 day of PPB. RESULTS: The mean duration of NHT was 4.0 +/- 1.1 months (range, 1-8 months). The mean prostate volume before NHT was 63.3 +/- 22.8 cc (range, 19-138 cc), and after NHT (before PPB), it was 41.6 +/- 16.4 cc (18-98 cc). The median prostate volume decrease after NHT was 22.7 cc or 34.9%. There was no significant difference in the degree of postimplantation prostate edema, as measured by the postimplantation to preimplantation ratio (1.18 +/- 0.05 [range, 0.8-1.9]) for the NHT group and 1.21 +/- 0.03 (range, 0.8-1.9) for the non-NHT group (P = 0.5). CONCLUSIONS: Prostate volume decreased by approximately one third after 4 months of NHT. NHT did not affect the degree of post-PPB prostatic edema.

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