The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

Theo H. Van Der Kwast - One of the best experts on this subject based on the ideXlab platform.

  • Detection of prostate cancer: a comparative study of the diagnostic efficacy of Sextant transrectal versus Sextant transperineal biopsy.
    Urology, 2000
    Co-Authors: André N. Vis, Michiel O Boerma, Stefano Ciatto, Robert F. Hoedemaeker, Fritz H. Schröder, Theo H. Van Der Kwast
    Abstract:

    Objectives. The optimal biopsy strategy for the detection of prostate cancer still needs to be established, since a considerable proportion of clinically significant cancers remains undiagnosed on routine Sextant transrectal biopsy. To assess the efficacy of transperineal biopsy to detect prostate cancer, we compared this approach to systematic Sextant transrectal biopsy in a simulation experiment. Methods. Ultrasound-guided Sextant transverse (transrectal) biopsy and subsequent Sextant longitudinal (transperineal) biopsy were performed on 40 radical prostatectomy specimens of patients with (transrectal) biopsy-detected prostate cancer. Conditions were simulative and may not be completely analogous to clinical settings. Ultrasound-determined prostate volume, biopsy tumor involvement, number of cores with cancer, and tumor volume were determined. Detailed mapping of radical prostatectomy specimens provided insight into the representativeness of the biopsy techniques. Results. Of 40 cancers, 33 (82.5%) were redetected by the transperineal approach; 29 (72.5%) were detected by repeated transrectal biopsies. For both approaches, the tumor volume of the undiagnosed cancers was significantly smaller (P

  • detection of prostate cancer a comparative study of the diagnostic efficacy of Sextant transrectal versus Sextant transperineal biopsy
    Urology, 2000
    Co-Authors: André N. Vis, Michiel O Boerma, Stefano Ciatto, Robert F. Hoedemaeker, Fritz H. Schröder, Theo H. Van Der Kwast
    Abstract:

    Objectives. The optimal biopsy strategy for the detection of prostate cancer still needs to be established, since a considerable proportion of clinically significant cancers remains undiagnosed on routine Sextant transrectal biopsy. To assess the efficacy of transperineal biopsy to detect prostate cancer, we compared this approach to systematic Sextant transrectal biopsy in a simulation experiment. Methods. Ultrasound-guided Sextant transverse (transrectal) biopsy and subsequent Sextant longitudinal (transperineal) biopsy were performed on 40 radical prostatectomy specimens of patients with (transrectal) biopsy-detected prostate cancer. Conditions were simulative and may not be completely analogous to clinical settings. Ultrasound-determined prostate volume, biopsy tumor involvement, number of cores with cancer, and tumor volume were determined. Detailed mapping of radical prostatectomy specimens provided insight into the representativeness of the biopsy techniques. Results. Of 40 cancers, 33 (82.5%) were redetected by the transperineal approach; 29 (72.5%) were detected by repeated transrectal biopsies. For both approaches, the tumor volume of the undiagnosed cancers was significantly smaller (P <0.01) and the prostate volume was significantly larger (P <0.01) than in the redetected ones. Between the two approaches, no difference was found for either of the variables determined in the redetected cancers. Prostate maps clarified that transperineal undiagnosed tumors were either small (0.2 cm3 or less) or notably located at the prostatic base. Conclusions. The biopsy procedure in which the biopsy needles enter the prostate at the apex for a longitudinal direction may efficiently sample the prostatic peripheral zone. Since the experiment was artificial in design, caution should be observed in extrapolating these results to patient settings.

Manolis Koubarakis - One of the best experts on this subject based on the ideXlab platform.

  • Sextant: Visualizing time-evolving linked geospatial data
    Journal of Web Semantics, 2015
    Co-Authors: Charalampos Nikolaou, Kostis Kyzirakos, George Garbis, Kallirroi Dogani, Manos Karpathiotakis, Konstantina Bereta, Manolis Koubarakis
    Abstract:

    The linked open data cloud is constantly evolving as datasets get continuously updated with newer versions. As a result, representing, querying, and visualizing the temporal dimension of linked data is crucial. This is especially important for geospatial datasets that form the backbone of large scale open data publication efforts in many sectors of the economy (e.g., the public sector, the Earth Observation sector). Although there has been some work on the representation and querying of linked geospatial data that change over time, to the best of our knowledge, there is currently no tool that offers spatio-temporal visualization of such data. This is in contrast with the existence of many tools for the visualization of the temporal evolution of geospatial data in the GIS area. In this article, we present Sextant, a Web-based system for the visualization and exploration of time-evolving linked geospatial data and the creation, sharing, and collaborative editing of “temporally-enriched” thematic maps which are produced by combining different sources of such data. We present the architecture of Sextant, give examples of its use and present applications in which we have deployed it.

  • Sextant visualizing time evolving linked geospatial data
    International Semantic Web Conference, 2013
    Co-Authors: Konstantina Bereta, Kostis Kyzirakos, Charalampos Nikolaou, Manos Karpathiotakis, Manolis Koubarakis
    Abstract:

    We present Sextant, a Web-based system for the visualization and exploration of time-evolving linked geospatial data and the creation, sharing, and collaborative editing of "temporally-enriched" thematic maps which are produced by combining different sources of such data.

André N. Vis - One of the best experts on this subject based on the ideXlab platform.

  • Detection of prostate cancer: a comparative study of the diagnostic efficacy of Sextant transrectal versus Sextant transperineal biopsy.
    Urology, 2000
    Co-Authors: André N. Vis, Michiel O Boerma, Stefano Ciatto, Robert F. Hoedemaeker, Fritz H. Schröder, Theo H. Van Der Kwast
    Abstract:

    Objectives. The optimal biopsy strategy for the detection of prostate cancer still needs to be established, since a considerable proportion of clinically significant cancers remains undiagnosed on routine Sextant transrectal biopsy. To assess the efficacy of transperineal biopsy to detect prostate cancer, we compared this approach to systematic Sextant transrectal biopsy in a simulation experiment. Methods. Ultrasound-guided Sextant transverse (transrectal) biopsy and subsequent Sextant longitudinal (transperineal) biopsy were performed on 40 radical prostatectomy specimens of patients with (transrectal) biopsy-detected prostate cancer. Conditions were simulative and may not be completely analogous to clinical settings. Ultrasound-determined prostate volume, biopsy tumor involvement, number of cores with cancer, and tumor volume were determined. Detailed mapping of radical prostatectomy specimens provided insight into the representativeness of the biopsy techniques. Results. Of 40 cancers, 33 (82.5%) were redetected by the transperineal approach; 29 (72.5%) were detected by repeated transrectal biopsies. For both approaches, the tumor volume of the undiagnosed cancers was significantly smaller (P

  • detection of prostate cancer a comparative study of the diagnostic efficacy of Sextant transrectal versus Sextant transperineal biopsy
    Urology, 2000
    Co-Authors: André N. Vis, Michiel O Boerma, Stefano Ciatto, Robert F. Hoedemaeker, Fritz H. Schröder, Theo H. Van Der Kwast
    Abstract:

    Objectives. The optimal biopsy strategy for the detection of prostate cancer still needs to be established, since a considerable proportion of clinically significant cancers remains undiagnosed on routine Sextant transrectal biopsy. To assess the efficacy of transperineal biopsy to detect prostate cancer, we compared this approach to systematic Sextant transrectal biopsy in a simulation experiment. Methods. Ultrasound-guided Sextant transverse (transrectal) biopsy and subsequent Sextant longitudinal (transperineal) biopsy were performed on 40 radical prostatectomy specimens of patients with (transrectal) biopsy-detected prostate cancer. Conditions were simulative and may not be completely analogous to clinical settings. Ultrasound-determined prostate volume, biopsy tumor involvement, number of cores with cancer, and tumor volume were determined. Detailed mapping of radical prostatectomy specimens provided insight into the representativeness of the biopsy techniques. Results. Of 40 cancers, 33 (82.5%) were redetected by the transperineal approach; 29 (72.5%) were detected by repeated transrectal biopsies. For both approaches, the tumor volume of the undiagnosed cancers was significantly smaller (P <0.01) and the prostate volume was significantly larger (P <0.01) than in the redetected ones. Between the two approaches, no difference was found for either of the variables determined in the redetected cancers. Prostate maps clarified that transperineal undiagnosed tumors were either small (0.2 cm3 or less) or notably located at the prostatic base. Conclusions. The biopsy procedure in which the biopsy needles enter the prostate at the apex for a longitudinal direction may efficiently sample the prostatic peripheral zone. Since the experiment was artificial in design, caution should be observed in extrapolating these results to patient settings.

Nikolaus T. Schmeller - One of the best experts on this subject based on the ideXlab platform.

  • One 10-core prostate biopsy is superior to two sets of Sextant prostate biopsies.
    BJU international, 2003
    Co-Authors: Klaus G. Fink, Georg Hutarew, Brigitte Esterbauer, Akos Pytel, Andreas Jungwirth, Otto Dietze, Nikolaus T. Schmeller
    Abstract:

    OBJECTIVES To compare the efficiency of different transrectal ultrasonography (TRUS)-guided prostate biopsy techniques for detecting prostate cancer. MATERIALS AND METHODS In all, 81 prostates from radical prostatectomy were used and two consecutive sets of Sextant biopsies and one 10-core biopsy taken in each specimen. The 10-core biopsy consisted of a Sextant biopsy and four cores from the far lateral areas of the prostate. To simulate a transrectal biopsy procedure, all biopsies were taken under TRUS guidance. RESULTS In the first set of Sextant biopsies 44 prostate cancers (54%) were detected and in the second set 51 (63%). Combining both sets of Sextant biopsies 57 (70%) of the carcinomas were detected. One set of 10-core biopsies detected 66 (82%) of all prostate cancers. Overall, with the 10-core biopsies 16% more prostate tumours were diagnosed than with two consecutive sets of Sextant biopsies. To find the same number of prostate cancers as with the 10-core technique, 14% of patients undergoing Sextant biopsy would require a second set and 11% at least a third set of biopsies. CONCLUSIONS The 10-core prostate biopsy technique is superior to the commonly used Sextant technique and could spare patients unnecessary repeated biopsy. Even after including a second set of Sextant biopsies, the total detection rate with these 12 biopsies was inferior to the 10-core technique.

  • Evaluation of transition zone and lateral Sextant biopsies for prostate cancer detection after initial Sextant biopsy
    Urology, 2003
    Co-Authors: Klaus G. Fink, Georg Hutarew, Brigitte Esterbauer, Akos Pytel, Andreas Jungwirth, Otto Dietze, Nikolaus T. Schmeller
    Abstract:

    Abstract Objectives To assess the value of transition zone and lateral Sextant biopsies for the detection of prostate cancer after a previous Sextant biopsy was negative. Methods A total of 74 prostates after radical prostatectomy were used to perform biopsies ex vivo. First, a Sextant biopsy was taken, then two different rebiopsy techniques were performed. Rebiopsy technique A consisted of a laterally placed Sextant biopsy and two cores per side of the transition zones only. Rebiopsy technique B included a standard Sextant biopsy and two cores per side from the lateral areas of the prostate. The biopsies were taken using ultrasound guidance to sample the areas of interest precisely. Results The initial Sextant biopsy found 39 prostate cancers. Rebiopsy technique A found 12 cancers (34%). In this group, a laterally placed Sextant biopsy found 12 cancers; transition zone biopsies revealed cancer in 5 cases, but no additional tumor was found. Rebiopsy technique B detected 23 prostate cancers (66%). Fourteen tumors were found after a second standard Sextant biopsy, and nine additional tumors were found in the lateral areas. Conclusions Sextant biopsy has a low sensitivity of only 53%. A biopsy including the transition zones is not the ideal technique for detecting the remaining tumors. Therefore, transition zone biopsies should be reserved for patients with multiple previous negative biopsies of the peripheral zone. A subsequent Sextant biopsy with additional cores from the lateral areas of the prostate is favorable if rebiopsy is necessary after a negative Sextant biopsy.

John N Kabalin - One of the best experts on this subject based on the ideXlab platform.

  • routine transition zone and seminal vesicle biopsies in all patients undergoing transrectal ultrasound guided prostate biopsies are not indicated
    The Journal of Urology, 1997
    Co-Authors: Martha K. Terris, Tien Q Pham, Muta M. Issa, John N Kabalin
    Abstract:

    ABSTRACTPurpose: Transrectal ultrasound guided biopsies of the transition zone and seminal vesicles have been useful in select patients. More widespread use of these additional biopsies has been proposed. The efficacy of routine transition zone and seminal vesicle biopsies was examined.Materials and Methods: From January 1988 to October 1994, 736 transrectal ultrasound guided systematic Sextant biopsies were performed. From October 1994 to July 1995, 161 consecutive patients underwent transrectal ultrasound with systematic Sextant, transition zone and seminal vesicle biopsies.Results: Of the 736 patients undergoing only Sextant biopsies 309 (42.0%) had cancer and 24 (3.3%) required repeat biopsy, compared to 55 (34.2%) and 4 (2.5%) of 161 undergoing combined Sextant, transition zone and seminal vesicle biopsies. Prostate cancer was found only in the systematic Sextant biopsies in 43 of the former 55 patients (78.2%), and in the transition zone and systematic Sextant biopsies in 11 (20.0%). One patient (1....