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Dawn R Comstock - One of the best experts on this subject based on the ideXlab platform.
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incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletes across 3 national surveillance systems
Journal of Athletic Training, 2019Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn R ComstockAbstract:Context Although sport-related Internal Organ injuries among athletes are relatively infrequent, combining data sources enables a more comprehensive examination of their incidence. Objective To des...
Ben J M Heijmen - One of the best experts on this subject based on the ideXlab platform.
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detection of Internal Organ movement in prostate cancer patients using portal images
Medical Physics, 2000Co-Authors: J Stroom, Marco Kroonwijk, Kasper L Pasma, Peter C M Koper, Erik B Van Dieren, Ben J M HeijmenAbstract:Previous research has indicated that the appearance of large gas pockets in portal images of prostate cancer patients might imply Internal prostate motion. This was verified with simulations based on multiple computed tomography (CT) data for 15 patients treated in supine position. Apart from the planning CT scan, three extra scans were made during treatment. The clinical target volume (CTV) and the rectum were outlined in all scans. Lateral portal images were simulated from the CT data and difference images were calculated for all possible combinations of CT scans per patient; each scan was used both as reference and repeat scan but gas pockets in the reference scan were removed. Gas pockets in a repeat CT scan then show up as black areas in a difference image. Due to gravity, they normally appear in the ventral part of the rectum. The distances between the ventral edge of a gas pocket in a difference image and the projection of the delineated ventral rectum wall in the reference scan were calculated. These distances were correlated with the "true" rectum wall shifts (determined from direct comparison of the rectum delineations in reference and repeat scan) and with CTV movements determined by three-dimensional chamfer matching. Gas pockets occurred in 23% of cases. Nevertheless, about 50% of rectum wall shifts larger than 5 mm could be detected because they were associated with gas pockets with a lateral diameter > 2 cm. When gas pockets were visible in the repeat scan, rectum wall shifts could be accurately detected by the ventral gas pocket edge in the difference images (r= 0.97). The shift of the rectum wall as detected from gas pockets also correlated significantly with the anterior-posterior shift of the center of mass of the CTV (r=0.88). In conclusion, the simulations showed that lateral pelvic images contain more information than the bony structures that are normally used for setup verification. If large gas pockets appear in those images, a quantitative estimate of the position of prostate and rectum wall can be obtained by determination of the ventral edge of the gas pocket.
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Internal Organ motion in prostate cancer patients treated in prone and supine treatment position
Radiotherapy and Oncology, 1999Co-Authors: J Stroom, Peter C M Koper, Gert A Korevaaar, Marjolein Janssen, Hans C J De Boer, Peter C Levendag, Ben J M HeijmenAbstract:Abstract Background and Purpose : To compare supine and prone treatment positions for prostate cancer patients with respect to Internal prostate motion and the required treatment planning margins. Materials and Methods : Fifteen patients were treated in supine and fifteen in prone position. For each patient, a planning computed tomography (CT) scan was used for treatment planning. Three repeat CT scans were made in weeks 2, 4, and 6 of the radiotherapy treatment. Only for the planning CT scan, laxation was used to minimise the rectal content. For all patients, the clinical target volume (CTV) consisted of prostate and seminal vesicles. Variations in the position of the CTV relative to the bony anatomy in the four CT scans of each patient were assessed using 3D chamfer matching. The overall variations were separated into variations in the mean CTV position per patient (i.e. the systematic component) and the average ‘day-to-day' variation (i.e. the random component). Required planning margins to account for the systematic and random variations in Internal Organ position and patient set-up were estimated retrospectively using coverage probability matrices. Results : The observed overall variation in the Internal CTV position was larger for the patients treated in supine position. For the supine and prone treatment positions, the random components of the variation along the anterior-posterior axis (i.e. towards the rectum) were 2.4 and 1.5 mm (1 standard deviation (1 SD)), respectively; the random rotations around the left-right axis were 3.0 and 2.9 degrees (1 SD). The systematic components of these motions (1 SD) were larger: 2.6 and 3.3 mm, and 3.7 and 5.6 degrees, respectively. The set-up variations were similar for both treatment positions. Despite the smaller overall variations in CTV position for the patients in prone position, the required planning margin is equal for both groups (about 1 cm except for 0.5 cm in lateral direction) due to the larger impact of the systematic variations. However, significant time trends cause a systematic ventral-superior shift of the CTV in supine position only. Conclusions : For Internal prostate movement, it is important to distinguish systematic from random variations. Compared to patients in supine position, patients in prone position had smaller random but somewhat larger systematic variations in the most important coordinates of the Internal CTV position. The estimated planning margins to account for the geometrical uncertainties were therefore similar for the two treatment positions.
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in vivo dosimetry for prostate cancer patients using an electronic portal imaging device epid demonstration of Internal Organ motion
Radiotherapy and Oncology, 1998Co-Authors: Marco Kroonwijk, Kasper L Pasma, S Quint, Peter C M Koper, A G Visser, Ben J M HeijmenAbstract:Purpose: To investigate the use of a commercially available video-based EPID for in vivo dosimetry during treatment of prostate cancer patients. Methods: For 10 prostate cancer patients, the inter-fraction variation within measured portal dose images (PDIs) was assessed and measured PDIs were compared with corresponding predicted PDIs based on the planning CT scan of the patient. Results: For the lateral fields, the average standard deviation in the measured on-axis portal doses during the course of a treatment was 0.9%; for the anterior fields this standard deviation was 2.2%. The difference between the average on-axis measured portal dose and the predicted portal dose was 0:3 ^ 2:1% (1 SD) for the lateral fields and 0:7 ^ 3:4% (1 SD) for the anterior fields. Off-axis differences between measured and predicted portal doses were regularly much larger (up to 15%) and were caused by frequently occurring gas pockets inside the rectum of the patients during treatment or during acquisition of the planning CT scan. The detected gas pockets did sometimes extend into the gross tumour volume (GTV) area as outlined in the planning CT scans, implying a shift of the anterior rectum wall and prostate in the anterior direction (Internal Organ motion). Conclusions: The developed procedures for measurement and prediction of PDIs allow accurate dosimetric quality control of the treatment of prostate cancer patients. Comparing measured PDIs with predicted PDIs can reveal Internal Organ motion. q 1998 Elsevier Science Ireland Ltd. All rights reserved.
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in vivo dosimetry for prostate cancer patients using an electronic portal imaging device epid demonstration of Internal Organ motion
Radiotherapy and Oncology, 1998Co-Authors: Marco Kroonwijk, Kasper L Pasma, S Quint, Peter C M Koper, A G Visser, Ben J M HeijmenAbstract:Purpose: To investigate the use of a commercially available video-based EPID for in vivo dosimetry during treatment of prostate cancer patients. Methods: For 10 prostate cancer patients, the inter-fraction variation within measured portal dose images (PDIs) was assessed and measured PDIs were compared with corresponding predicted PDIs based on the planning CT scan of the patient. Results: For the lateral fields, the average standard deviation in the measured on-axis portal doses during the course of a treatment was 0.9%; for the anterior fields this standard deviation was 2.2%. The difference between the average on-axis measured portal dose and the predicted portal dose was 0:3 ^ 2:1% (1 SD) for the lateral fields and 0:7 ^ 3:4% (1 SD) for the anterior fields. Off-axis differences between measured and predicted portal doses were regularly much larger (up to 15%) and were caused by frequently occurring gas pockets inside the rectum of the patients during treatment or during acquisition of the planning CT scan. The detected gas pockets did sometimes extend into the gross tumour volume (GTV) area as outlined in the planning CT scans, implying a shift of the anterior rectum wall and prostate in the anterior direction (Internal Organ motion). Conclusions: The developed procedures for measurement and prediction of PDIs allow accurate dosimetric quality control of the treatment of prostate cancer patients. Comparing measured PDIs with predicted PDIs can reveal Internal Organ motion. q 1998 Elsevier Science Ireland Ltd. All rights reserved.
Kristen L Kucera - One of the best experts on this subject based on the ideXlab platform.
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incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletes across 3 national surveillance systems
Journal of Athletic Training, 2019Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn R ComstockAbstract:Context Although sport-related Internal Organ injuries among athletes are relatively infrequent, combining data sources enables a more comprehensive examination of their incidence. Objective To des...
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54 incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletic participants across three national surveillance systems
Injury Prevention, 2017Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn ComstockAbstract:Purpose Describe the incidence and characteristics of sport-related Internal Organ injuries due to direct contact mechanisms among high school (HS) and collegiate athletic participants from 2005/06–2014/15. Methods Data from three national sports injury surveillance systems were analysed: High School Reporting Information Online (RIO; HS), National Collegiate Athletic Association Injury Surveillance Program (ISP; college), and the National Centre for Catastrophic Sport Injury Research (NCCSIR; college and HS). Internal Organ injuries were defined as: affecting the Internal Organs (e.g., kidney, lung); due to direct contact mechanism; resulting in medical care and time loss of 1 or more days (RIO and ISP) or temporary or permanent disability or death (NCCSIR). Descriptive statistics (stratified by surveillance system) included frequencies and incidence rates per 1,000,000 athlete-exposures and 95% confidence intervals (IR: 95% CI). Results During the ten-year period, 174 Internal Organ injuries were captured across the three systems: 124 HS (RIO); 41 collegiate (ISP); and 9 catastrophic (NCCSIR). Most non-catastrophic Internal Organ injuries occurred among males (85% RIO; 89% ISP), in football (65% RIO; 58% ISP), during competition (67% RIO; 49% ISP) and due to player-player contact (78% RIO; 68% ISP). The highest rates of injury were in male contact sports: RIO: HS football (IR=11.7: 9.1–14.2), HS lacrosse (IR=10.0: 3.1–16.9); ISP: college football (IR=8.3: 5.0–11.6), college ice hockey (IR=7.9: 1.0–14.7). A quarter of Internal Organ injuries were season-ending (25% RIO; 23% ISP). Of the 9 catastrophic injuries (NCCSIR), most occurred in high school (7/9) and football (7/9) and were due to player-player contact (6/9). Four resulted in death and 5 resulted in disability. Conclusions Direct contact Internal Organ injuries occur infrequently, yet when they do occur, may result in severe outcomes. Significance These findings suggest early recognition and a better understanding of the activities associated with the event and use/non-use of protective equipment is needed.
Erin B Wasserman - One of the best experts on this subject based on the ideXlab platform.
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incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletes across 3 national surveillance systems
Journal of Athletic Training, 2019Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn R ComstockAbstract:Context Although sport-related Internal Organ injuries among athletes are relatively infrequent, combining data sources enables a more comprehensive examination of their incidence. Objective To des...
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54 incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletic participants across three national surveillance systems
Injury Prevention, 2017Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn ComstockAbstract:Purpose Describe the incidence and characteristics of sport-related Internal Organ injuries due to direct contact mechanisms among high school (HS) and collegiate athletic participants from 2005/06–2014/15. Methods Data from three national sports injury surveillance systems were analysed: High School Reporting Information Online (RIO; HS), National Collegiate Athletic Association Injury Surveillance Program (ISP; college), and the National Centre for Catastrophic Sport Injury Research (NCCSIR; college and HS). Internal Organ injuries were defined as: affecting the Internal Organs (e.g., kidney, lung); due to direct contact mechanism; resulting in medical care and time loss of 1 or more days (RIO and ISP) or temporary or permanent disability or death (NCCSIR). Descriptive statistics (stratified by surveillance system) included frequencies and incidence rates per 1,000,000 athlete-exposures and 95% confidence intervals (IR: 95% CI). Results During the ten-year period, 174 Internal Organ injuries were captured across the three systems: 124 HS (RIO); 41 collegiate (ISP); and 9 catastrophic (NCCSIR). Most non-catastrophic Internal Organ injuries occurred among males (85% RIO; 89% ISP), in football (65% RIO; 58% ISP), during competition (67% RIO; 49% ISP) and due to player-player contact (78% RIO; 68% ISP). The highest rates of injury were in male contact sports: RIO: HS football (IR=11.7: 9.1–14.2), HS lacrosse (IR=10.0: 3.1–16.9); ISP: college football (IR=8.3: 5.0–11.6), college ice hockey (IR=7.9: 1.0–14.7). A quarter of Internal Organ injuries were season-ending (25% RIO; 23% ISP). Of the 9 catastrophic injuries (NCCSIR), most occurred in high school (7/9) and football (7/9) and were due to player-player contact (6/9). Four resulted in death and 5 resulted in disability. Conclusions Direct contact Internal Organ injuries occur infrequently, yet when they do occur, may result in severe outcomes. Significance These findings suggest early recognition and a better understanding of the activities associated with the event and use/non-use of protective equipment is needed.
Zachary Y Kerr - One of the best experts on this subject based on the ideXlab platform.
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incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletes across 3 national surveillance systems
Journal of Athletic Training, 2019Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn R ComstockAbstract:Context Although sport-related Internal Organ injuries among athletes are relatively infrequent, combining data sources enables a more comprehensive examination of their incidence. Objective To des...
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54 incidence of sport related Internal Organ injuries due to direct contact mechanisms among high school and collegiate athletic participants across three national surveillance systems
Injury Prevention, 2017Co-Authors: Kristen L Kucera, Dustin W Currie, Erin B Wasserman, Zachary Y Kerr, Leah C Thomas, Stephen Paul, Dawn ComstockAbstract:Purpose Describe the incidence and characteristics of sport-related Internal Organ injuries due to direct contact mechanisms among high school (HS) and collegiate athletic participants from 2005/06–2014/15. Methods Data from three national sports injury surveillance systems were analysed: High School Reporting Information Online (RIO; HS), National Collegiate Athletic Association Injury Surveillance Program (ISP; college), and the National Centre for Catastrophic Sport Injury Research (NCCSIR; college and HS). Internal Organ injuries were defined as: affecting the Internal Organs (e.g., kidney, lung); due to direct contact mechanism; resulting in medical care and time loss of 1 or more days (RIO and ISP) or temporary or permanent disability or death (NCCSIR). Descriptive statistics (stratified by surveillance system) included frequencies and incidence rates per 1,000,000 athlete-exposures and 95% confidence intervals (IR: 95% CI). Results During the ten-year period, 174 Internal Organ injuries were captured across the three systems: 124 HS (RIO); 41 collegiate (ISP); and 9 catastrophic (NCCSIR). Most non-catastrophic Internal Organ injuries occurred among males (85% RIO; 89% ISP), in football (65% RIO; 58% ISP), during competition (67% RIO; 49% ISP) and due to player-player contact (78% RIO; 68% ISP). The highest rates of injury were in male contact sports: RIO: HS football (IR=11.7: 9.1–14.2), HS lacrosse (IR=10.0: 3.1–16.9); ISP: college football (IR=8.3: 5.0–11.6), college ice hockey (IR=7.9: 1.0–14.7). A quarter of Internal Organ injuries were season-ending (25% RIO; 23% ISP). Of the 9 catastrophic injuries (NCCSIR), most occurred in high school (7/9) and football (7/9) and were due to player-player contact (6/9). Four resulted in death and 5 resulted in disability. Conclusions Direct contact Internal Organ injuries occur infrequently, yet when they do occur, may result in severe outcomes. Significance These findings suggest early recognition and a better understanding of the activities associated with the event and use/non-use of protective equipment is needed.