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We assessed correlation between hazard ratios of imaging-based intermediate endpoints (IBIEs) and overall survival among 28 Prostate Cancer Working Group 2-based phase II-III randomized trials evaluating systemic treatments in 16,511 metastatic castration-resistant prostate cancer patients. The overall correlation was good (R2 = 0.57). Trials using radiographic progression-free survival showed higher correlation than those using a composite IBIE (including clinical factors in the definition of progression): R2 = 0.58 vs. 0.00. Introduction/Background: Radiographic progression-free survival (rPFS) based on Prostate Cancer Working Group 2 (PCWG2) has been increasingly used as a meaningful imaging-based intermediate endpoint (IBIE) for overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC). In randomized phase III trials, rPFS showed good correlation with OS at the individual trial level. We aimed to assess the correlation between the hazard ratios (HR) of IBIE and OS among PCWG2-based randomized trials. Materials and Methods: PubMed and EMBASE databases were systematically searched for randomized trials evaluating systemic treatments on mCRPC using PCWG2 up to April 15, 2020. Hazard ratios for OS and IBIEs were extracted and their correlation was assessed using weighted linear regression. Subgroup analyses were performed according to var ious clinical settings: pr ior chemotherapy, dr ug category, type of IBIE (rPFS vs. composite IBIE, latter defined as progression by imaging and one or a combination of PSA, pain, skeletal-related events, and performance status), and publication year. Results: Twenty-eight phase II-III randomized trials (16,511 patients) were included. Correlation between OS and IBIE was good (R² = 0.57, 95% confidence interval [CI], 0.35-0.78). Trials using rPFS showed substantially higher correlation than those using a composite IBIE (R² = 0.58, 95% CI, 0.32-0.82 vs. 0.00, 95% CI, -0.01 to 0.01). Correlations between OS and IBIE in other subgroups were at least moderate in nearly all subgroups (R² = 0.32-0.91). Conclusion: IBIEs in the era of PCWG2 correlate well with OS in randomized trials for systemic drugs in patients with mCRPC. PCWG2-based rPFS should be used instead of a composite IBIE that includes PSA and other clinical variables. [ABSTRACT FROM AUTHOR]

Purpose: To assess the intraobserver reproducibility of shear wave elastography (SWE) in the prostate. Materials and methods: This study was institutional review board approved with waiver of informed consent. Eighty men (mean age, 66.2±9.2 years) with suspected prostate cancer underwent SWE. Young modulus (kPa) was measured at 24 locations in the prostate (superficial and deep locations in paramedian and lateral aspects at the base, mid-gland, and apex levels). The intraobserver reproducibility of two repeated measurements was determined using intraclass correlation coefficients (ICC) and was compared among measurement location, prostate volume, age, and prostate-specific antigen level. Results: The overall intraobserver reproducibility was excellent (ICC=0.876). In addition, intraobserver reproducibility was excellent for all specified subgroups according to location, prostate volume, and clinical variables (ICC=0.826-0.917).With regard to location, SWE measurements showed substantially higher ICC values in the mid-gland than in the base and apex, in the paramedian prostate than in the lateral prostate, and in superficial locations than in deeper locations. No substantial differences in ICC values were observed according to the prostate volume and clinical variables. Conclusion: Intraobserver reproducibility of SWE measurements in the prostate gland was excellent. There was variability in the intraobserver reproducibility according to location within the prostate, and the operator should be aware of this and take extra caution when performing SWE in these areas. [ABSTRACT FROM AUTHOR]

Artificial crystals synthesized by atomic-scale epitaxy provide the ability to control the dimensions of the quantum phases and associated phase transitions via precise thickness modulation. In particular, the reduction in dimensionality via quantized control of atomic layers is a powerful approach to revealing hidden electronic and magnetic phases. Here, we demonstrate a dimensionality-controlled and induced metal-insulator transition (MIT) in atomically designed superlattices by synthesizing a genuine two-dimensional (2D) SrRuO3 crystal with highly suppressed charge transfer. The tendency to ferromagnetically align the spins in an SrRuO3 layer diminishes in 2D as the interlayer exchange interaction vanishes, accompanying the 2D localization of electrons. Furthermore, electronic and magnetic instabilities in the two SrRuO3 unit cell layers induce a thermally driven MIT along with a metamagnetic transition. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms. Methods: To address the accuracy of the transducer, hydrophones in a water chamber were used to assess the generation of sonic fields. An animal study was also performed in five pigs by ablating in vivo thighs by single-point sonication (n=10) or volume sonication (n=10) and ex vivo kidneys by single-point sonication (n=10). Histological and statistical analyses were performed. Results: In the hydrophone study, peak voltages were detected within 1.0 mm from the targets on the y- and z-axes and within 2.0-mm intervals along the x-axis (z-axis, direction of ultrasound propagation; y- and x-axes, perpendicular to the direction of ultrasound propagation). Twentynine of 30 HIFU sessions successfully created ablations at the target. The in vivo porcine thigh study showed only a small discrepancy (width, 0.5-1.1 mm; length, 3.0 mm) between the planning ultrasonograms and the pathological specimens. Inordinate thermal damage was not observed in the adjacent tissues or sonic pathways in the in vivo thigh and ex vivo kidney studies. Conclusion: Our study suggests that this new USg-HIFU system may be a safe and accurate technique for ablating soft tissues and encapsulated organs. [ABSTRACT FROM AUTHOR]