Effectiveness of Initial Fixation of a Grasping Pin for Proximal Femoral Fractures

We developed a grasping pin with a hook for osteosynthesis of proximal femoral fractures and compared its performance with that of a lag screw. Cyclic compressive tests were performed to simulate cut-outs, and quasi-static torsion, tests were conducted to simulate rotational displacement in polyurethane model bones and femoral heads collected after hip replacement surgery, and cadaveric femoral heads. In the polyurethane model bones and femoral head collected after hip replacement surgery, implant displacement was increased in the cut-out simulation test in both the grasping pin group and lag screw group, deformation was less in the grasping pin group than in the lag screw group. In polyurethane bones and cadaveric bones, the grasping pins showed higher rotational resistance compared with the lag screws in the quasi-static torsion test because of the high compression force generated during implantation. In contrast, in the collected femoral head after hip replacement surgery model, the lag screws destroyed bone tissue, the lag screw group exhibited a higher rotational resistance and a lower risk of rotational displacement than the grasping pin model. The depth of cadaveric femoral heads was 60mm compared with 30mm for femoral heads obtained after surgery; therefore, the pins could be completely inserted up to the octagonal portion in the cadaveric bones, resulting in higher rotational resistance

Evaluation of image quality of pituitary dynamic contrast-enhanced MRI using time-resolved angiography with interleaved stochastic trajectories (TWIST) and iterative reconstruction TWIST (IT-TWIST)

Background: Time‐resolved angiography with interleaved stochastic trajectories (TWIST) is a keyhole imaging with frequent sampling of central k‐space data and view‐sharing for the peripheral k‐space of dynamic phases. IT‐TWIST is a technique to reconstruct images with a smaller temporal footprint using the same raw data obtained with TWIST by iterative reconstruction. Purpose: To compare image quality between TWIST and IT‐TWIST in 3D pituitary DCE‐MRI. Study Type: Retrospective observation study. Population: Fifty‐one patients (23 men, 28 women) who underwent 3D pituitary DCE‐MRI using TWIST between July 2016 and April 2017. Field Strength/Sequence: 3T/TWIST and IT‐TWIST. Assessment: Visual evaluation was conducted for image quality of delineation of the pituitary stalk and posterior lobe during the early arterial phase, cerebral white matter near the sella turcica, and the mass lesion. Bolus sharpness of the pituitary stalk, posterior lobe, and bilateral cavernous sinus was evaluated on the enhancement slope map calculated from TWIST and IT‐TWIST. Temporal stability of intensity of the nonenhanced area was evaluated on temporal standard deviation (SD) maps calculated from TWIST and IT‐TWIST. Statistical Tests: Paired t‐test or Wilcoxon rank‐sum test was used to test the differences between TWIST and IT‐TWIST in both visual evaluation and region of interest evaluation. Results: Scores of visual evaluations for IT‐TWIST were significantly better than those for TWIST (P < 0.001) in all items. Enhancement slope for IT‐TWIST was significantly higher than that for TWIST in posterior lobe, and right and left cavernous sinus (P < 0.001). Temporal SD for IT‐TWIST was significantly lower than that for TWIST in all items, with statistical significance (P < 0.001). Data Conclusion: IT‐TWIST yielded better visualization, and better enhancement slope, and less temporal SD compared with TWIST in 3D pituitary DCE‐MRI

Efficacy and Safety of High-Dose-Rate Brachytherapy of Single Implant with Two Fractions Combined with External Beam Radiotherapy for Hormone-Naïve Localized Prostate Cancer

The purpose of this study was to evaluate the efficacy and safety of high-dose-rate (HDR) brachytherapy of a single implant with two fractions plus external beam radiotherapy (EBRT) for hormone-naïve prostate cancer in comparison with radical prostatectomy. Of 150 patients with localized prostate cancer (T1c–T2c), 59 underwent HDR brachytherapy plus EBRT, and 91 received radical prostatectomy. The median follow-up of patients was 62 months for HDR brachytherapy plus EBRT, and 64 months for radical prostatectomy. In patient backgrounds between the two cohorts, the frequency of T2b plus T2c was greater in HDR brachytherapy cohort than in prostatectomy cohort (27% versus 12%, p = 0.029). Patients in HDR brachytherapy cohort first underwent 3D conformal RT with four beams to the prostate to an isocentric dose of 50 Gy in 25 fractions and then, a total of 15–18 Gy in two fractions at least 5 hours apart. We prescribed 9 Gy/fraction for target (prostate gland plus 3 mm lateral outside margin and seminal vesicle) using CT image method for radiation planning. The total biochemical failure-free control rates (BF-FCR) at 3 and 5 years for the HDR brachytherapy cohort, and for the prostatectomy cohort were 92% and 85%, and 72% and 72%, respectively (significant difference, p = 0.0012). The 3-and 5-year BF-FCR in the HDR brachytherapy cohort and in the prostatectomy cohort by risk group was 100 and 100%, and 80 and 80%, respectively, for the low-risk group (p = 0.1418); 92 and 92%, 73 and 73%, respectively, for the intermediate-risk group (p = 0.0492); and 94 and 72%, 45 and 45%, respectively, for the high-risk group (p = 0.0073). After HDR brachytherapy plus EBRT, no patient experienced Grade 2 or greater genitourinay toxicity. The rate of late Grade 1 and 2 GI toxicity was 6% (n = 4). No patient experienced Grade 3 GI toxicity. HDR brachytherapy plus EBRT is useful for treating patients with hormone-naïve localized prostate cancer, and has low GU and GI toxicities