Sex-specific associations of serum testosterone with gray matter volume and cerebral blood flow in midlife individuals at risk for Alzheimer's disease.

Testosterone, an essential sex steroid hormone, influences brain health by impacting neurophysiology and neuropathology throughout the lifespan in both genders. However, human research in this area is limited, particularly in women. This study examines the associations between testosterone levels, gray matter volume (GMV) and cerebral blood flow (CBF) in midlife individuals at risk for Alzheimer's disease (AD), according to sex and menopausal status.

Evaluation of ion recombination and polarity effect on photon depth dose measurements using mini- and micro-ion chamber.

Purpose: To investigate the effect of ion recombination ( ) and polarity ( ) correction factors on percentage depth dose (PDD) curves for three ion chambers, using flat and flattening filter free (FFF) beams, across different broad field sizes. A method to assess these effects and their corresponding corrections is proposed.

Methods: and were evaluated following the IAEA TRS-398 protocol for three ion chambers: PTW Semiflex-3D-31021, PinPoint-3D-31022, and Semiflex-31010.

Machine learning and lean six sigma for targeted patient-specific quality assurance of volumetric modulated arc therapy plans.

Background And Purpose: Radiotherapy plans with excessive complexity exhibit higher uncertainties and worse patient-specific quality assurance (PSQA) results, while the workload of measurement-based PSQA can impact the efficiency of the radiotherapy workflow. Machine Learning (ML) and Lean Six Sigma, a process optimization method, were implemented to adopt a targeted PSQA approach, aiming to reduce workload, risk of failures, and monitor complexity.

Materials And Methods: Lean Six Sigma was applied using DMAIC (define, measure, analyze, improve, and control) steps.

STRILL: Phase I Trial Evaluating Stereotactic Body Radiotherapy (SBRT) Dose Escalation for Re-Irradiation of Inoperable Peripheral Lung Lesions.

Few data are available on the role of SBRT re-irradiation for isolated recurrences. We designed a prospective phase I study to evaluate the maximum tolerated dose (MTD) of SBRT for thoracic re-irradiation, for peripheral lung lesions. RT was delivered with a dose escalation design from 30 Gy in five fractions up to 50 Gy in five fractions.

In vivo brain estrogen receptor density by neuroendocrine aging and relationships with cognition and symptomatology.

17β-estradiol, the most biologically active estrogen, exerts wide-ranging effects in brain through its action on estrogen receptors (ERs), influencing higher-order cognitive function and neurobiological aging. However, our knowledge of ER expression and regulation by neuroendocrine aging in the living human brain is limited. This in vivo brain F-fluoroestradiol (F-FES) Positron Emission Tomography (PET) study of healthy midlife women reveals progressively higher ER density over the menopause transition in estrogen-regulated networks.