Thomassen McLean (lunchshadow5)
Studies investigating biomechanical risk factors for knee injuries in sport-specific tasks are needed. To investigate the association between change of direction (COD) biomechanics in a 180-degree pivot turn and knee injury risk among youth team sport players. Cohort study; Level of evidence, 2. A total of 258 female and male basketball and floorball players (age range, 12-21 years) participated in the baseline COD test and follow-up. Complete data were obtained from 489 player-legs. Injuries, practice, and game exposure were registered for 12 months. The COD test consisted of a quick ball pass before and after a high-speed 180-degree pivot turn on the force plates. The following variables were analyzed peak vertical ground-reaction force (N/kg); peak trunk lateral flexion angle (degree); peak knee flexion angle (degree); peak knee valgus angle (degree); peak knee flexion moment (N·m/kg); peak knee abduction moment (N·m/kg); and peak knee internal and external rotation moments (N·m/kg). Legs were analgated variables was associated with knee injury risk in youth basketball and floorball players. Female players were at increased risk of knee and ACL injury compared with male players. Female players performed the 180-degree pivot turn with significantly larger knee valgus compared with male players. However, none of the investigated variables was associated with knee injury risk in youth basketball and floorball players. The most commonly used dose for prostate cancer stereotactic body radiotherapy (SBRT) is 5 × 7.25 Gy. The aim of this study was to evaluate the dosimetric feasibility of a 5 × 9 Gy SBRT regimen while still limiting the dose to the urethra to 5 × 7.25 Gy. This dosimetric study is part of the groundwork for a future Phase III randomized trial. The prostate, the urethra and the tumors were delineated on 20 dosimetric CT-scans with MRI-registration. The planning target volume (PTVp) was defined as a 5 mm expansion (3 mm posteriorly) of the prostate. The planning at risk volume (PRVu) was defined as a 2 mm expansion of the urethra. The tumors were delineated on the MRI (GTVt) and a 3 mm-margin was added to create a tumoral planning target volume (PTVt). IMRT plans were optimized to deliver 5 × 9 Gy to the PTVp, limiting the dose to the PRVu to 5 × 7.25 Gy. Results are presented using average (range) values. PTVp doses were D98% = 36.2 Gy (35.6-36.8), D2% = 46.9 Gy (46.5-47.5) and mean dose = 44.1 Gy (43.8-44.5). The dose to the PRVu was within tolerance limits for all 20 patients V34.4Gy = 99.8% (99.2-100) and D5% = 38.7 Gy (38.6-38.8). Dose coverage of PTV-PRVu was D95% = 40.6 Gy (40.5-40.9), D5% = 46.6 Gy (46.2-47.2) and mean dose = 44.6 Gy (44.3-44.9). Dose to the PTVt reached 44.6 Gy (41.2-45.9). Doses to the OAR were respected, except V36Gy ≤1 cc for the rectum. A SBRT dose-escalation to 5 × 9 Gy on the prostate while sparing the urethra + 2 mm at 36.25 Gy is feasible without compromising dose coverage to the tumor. This radiation regimen will be used for a Phase-III trial. In prostate SBRT, dose optimization on the urethra is feasible and could decrease urinary toxicities. In prostate SBRT, dose optimization on the urethra is feasible and could decrease urinary toxicities. MR-guided daily-adaptive radiotherapy is improving the accuracy in the planning and delivery phases of the treatment. Rectal hydrogel-spacer may help in mitigating organ motion, but few data are currently available. We aimed to assess any potential impact of the device on seminal vesicles motion by measuring translational and rotational shifts between the pre- and post-treatment MRI scans of a total of 50 fractions in the first 10 patients who underwent MR-guided prostate SBRT (35 Gy/5 fx). Of them, five patients received the hydrogel-spacer. The comparative analysis was performed using the Mann-Whitney U-test. Me