Effects of Oral ALZ-801/Valiltramiprosate on Plasma Biomarkers, Brain Hippocampal Volume, and Cognition: Results of 2-Year Single-Arm, Open-Label, Phase 2 Trial in APOE4 Carriers with Early Alzheimer's Disease.

Introduction: ALZ-801/valiltramiprosate is a small-molecule oral inhibitor of beta amyloid (Aβ) aggregation and oligomer formation being studied in a phase 2 trial in APOE4 carriers with early Alzheimer's disease (AD) to evaluate treatment effects on fluid and imaging biomarkers and cognitive assessments.

Methods: The single-arm, open-label phase 2 trial was designed to evaluate the effects of the ALZ-801 265 mg tablet taken twice daily (after 2 weeks once daily) on plasma fluid AD biomarkers, hippocampal volume (HV), and cognition over 104 weeks in APOE4 carriers. The study enrolled subjects aged 50-80 years, with early AD [Mini-Mental State Examination (MMSE) ≥ 22, Clinical Dementia Rating-Global (CDR-G) 0.

What Do Medical Physicists Do? Leadership and Challenges in Administration and Various Business Functions.

The goal of the present study was to investigate the primary role of medical physicists (MPs) in radiation oncology (RO) administration and key business functions, besides various challenges facing today. An experienced MP leader formulates a well-structured department administration and management system in RO. The essential role of MP team leaders in health care is not only limited to supervising routine department clinical works but also being substantially involved in key business functions such as leadership, operations, project management, decision making, and many more.

Quantitative Medical Physics National Job Data Distribution Analysis.

Purpose: The purpose of this study was to investigate the contemporary distribution of medical physics (MP) employment opportunities across the United States.

Methods And Materials: An annual record (2018-2019) of advertised full-time MP jobs was created using publicly available information from the American Association of Physicists in Medicine and Indeed websites. Listed jobs were categorized based on position name, work experience, job function, and geographic region.

Early Assessment of Treatment Responses During Radiation Therapy for Lung Cancer Using Quantitative Analysis of Daily Computed Tomography.

Purpose: To investigate early tumor and normal tissue responses during the course of radiation therapy (RT) for lung cancer using quantitative analysis of daily computed tomography (CT) scans.

Methods And Materials: Daily diagnostic-quality CT scans acquired using CT-on-rails during CT-guided RT for 20 lung cancer patients were quantitatively analyzed. On each daily CT set, the contours of the gross tumor volume (GTV) and lungs were generated and the radiation dose delivered was reconstructed.

Effect of diagnostic cone-beam computed tomography protocols on image quality, patient dose, and lesion detection.

Objective: To evaluate the effect of cone-beam computed tomography (CBCT) image acquisition protocols on image quality, lesion detection, delineation, and patient dose.

Methods: 100-patients and a CTDI phantom combined with an electron density phantom were examined using four different CBCT-image acquisition protocols during image-guided transarterial chemoembolization (TACE). Protocol-1 (time: 6s, tube rotation: 360°), protocol-2 (5s, 300°), protocol-3 (4s, 240°) and protocol-4 (3s, 180°) were used.

Detectability of hepatic tumors during 3D post-processed ultrafast cone-beam computed tomography.

To evaluate hepatic tumor detection using ultrafast cone-beam computed tomography (UCBCT) cross-sectional and 3D post-processed image datasets. 657 patients were examined using UCBCT during hepatic transarterial chemoembolization (TACE), and data were collected retrospectively from January 2012 to September 2014. Tumor detectability, diagnostic ability, detection accuracy and sensitivity were examined for different hepatic tumors using UCBCT cross-sectional, perfusion blood volume (PBV) and UCBCT-MRI (magnetic resonance imaging) fused image datasets.

Dual energy computed tomography thermometry during hepatic microwave ablation in an ex-vivo porcine model.

Background: Microwave thermoablation (MTA) is a treatment method used to destroy hepatic tumors.

Objective: To investigate temperature changes during MTA of ex-vivo porcine liver using dual-energy computed tomography (DECT) imaging.

Methods: Three MTA experiments were performed using ex-vivo porcine liver (15 × 15 × 15 cm(3)) and DECT imaging with 80/Sn140 kVp spectral and 0.

Ultrafast cone-beam computed tomography: a comparative study of imaging protocols during image-guided therapy procedure.

Objective: To evaluate two ultrafast cone-beam CT (UF-CBCT) imaging protocols with different acquisition and injection parameters regarding image quality and required contrast media during image-guided hepatic transarterial chemoembolization (TACE).

Methods: In 80 patients (male: 46, female: 34; mean age: 56.8 years; range: 33-83) UF-CBCT was performed during TACE for intraprocedural guidance.

Cone-beam computed tomography imaging: therapeutic staff dose during chemoembolisation procedure.

Cone-beam computed tomography (CBCT) imaging is an important requirement to perform real-time therapeutic image-guided procedures on patients. The purpose of this study is to estimate the personal-doseequivalent and annual-personal-dose from CBCT imaging during transarterial chemoembolisation (TACE). Therapeutic staff doses (therapeutic and assistant physician) were collected during 200 patient (65 ± 15 years, range: 40–86) CBCT examinations over six months.

Ablation therapy of hepatocellular carcinoma: a comparative study between radiofrequency and microwave ablation.

Purpose: The aim of the study is to retrospectively evaluate and compare the therapeutic response of Radiofrequency (RF) and Microwave (MW) ablation therapy of hepatocellular carcinoma (HCC).

Materials And Methods: 53 consecutive patients (42 males, 11 females; mean age 59 years, range: 40-68, SD: 4.2) underwent CT-guided percutaneous RF and MW ablation of 68 HCC liver lesions.

Image-guided microwave thermoablation of hepatic tumours using novel robotic guidance: an early experience.

Objective: To evaluate and compare novel robotic guidance and manual approaches based on procedural accuracy, procedural time, procedural performance, image quality as well as patient dose during image-guided microwave thermoablation.

Method: The study was prospectively performed between June 2013 and December 2013 using 70 patients. Forty randomly selected patients (group 1) were treated with manual guidance and 30 patients (group 2) were treated using a novel robotic guidance.

CT chest and gantry rotation time: does the rotation time influence image quality?

Background: Computed tomography (CT) gantry rotation time is one factor influencing image quality. Until now, there has been no report investigating the influence of gantry rotation time on chest CT image quality.

Purpose: To investigate the influence of faster gantry rotation time on image quality and subjective and objective image parameters in chest CT imaging.

Ultrafast cone-beam computed tomography imaging and postprocessing data during image-guided therapeutic practice.

Objective: Our objective was to evaluate ultrafast cone-beam computed tomography (u-CBCT) image data using cross-sectional images, perfusion blood volume (PBV), and image fusion during tumour detection at the course of transarterial chemoembolization.

Methods: One hundred and fifty patients (63 ± 20 years; 33-82) were examined from February to October 2013 with u-CBCT. Tumour delineation and conspicuity were determined using u-CBCT cross-sectional PBV and u-CBCT-magnetic resonance imaging (MRI) fused data sets for hyperenhanced (HYET), heterogeneously enhanced (HEET), and unenhanced (UET) tumour categories.

Oncological applications of dual-energy computed tomography imaging.

Dual-energy computed tomography (DECT) imaging is a promising method used in oncology for accurate detection/diagnosis of malignant and benign lesions. Use of dual-energy spectral, weighted average, color-coded map, and virtual unenhanced images provides increased visual detection and easy lesion delineation. Lesion detectability, sensitivity, and conspicuity are significantly improved using DECT.

Dual-energy CT spectral and energy weighted data sets: carotid stenosis and plaque detection.

Rationale And Objectives: To evaluate dual-energy computed tomography spectral and energy weighted (W) image data sets concerning carotid stenosis and calcified plaque detection.

Materials And Methods: Ninety patients were evaluated using contrast media injection. Energy used for dual-energy computed tomography was tin filter with 140/80 kiloVoltage and effective milli Ampere second was 147.

Magnetic resonance temperature imaging of laser-induced thermotherapy: assessment of fast sequences in ex vivo porcine liver.

Aim: To evaluate magnetic resonance sequences for T(1) and proton resonance frequency (PRF) thermometry during laser-induced thermotherapy (LITT) in liver tissue.

Materials & Methods: During LITT (1064 nm; 30 W; 3-cm diffuser; 2-3 min) in ex vivo porcine liver, temperature was measured (25-70°C) utilizing a fiberoptic thermometer and MRI was performed with a 1.5-T scanner through the following sequences: segmented echo planar imaging (seg-EPI) for the PRF method; fast low-angle shot (FLASH), inversion-recovery turbo FLASH (IRTF), saturation-recovery turbo FLASH (SRTF) and true-fast imaging (TRUFI) for the T(1) method.

Radiation dose to procedural personnel and patients from an X-ray volume imaging system.

Objective: To evaluate the radiation dose received by procedural personnel and patients from an X-ray volume imaging (XVI) system during interventional procedures.

Methods: Forty patients were examined using catheter angiography (group A), digital subtraction angiography (group B) and cone-beam CT (CBCT, group C). Doses to procedural personnel (using thermo-luminescent dosimeters, TLDs) and patients were estimated.

Effect of contrast material on radiation dose in an adult cardiac dual-energy CT using retrospective ECG-gating.

The purpose of this study was to determine the effect of contrast material and retrospective ECG-gating on radiation dose in an adult cardiac dual-energy computed tomography (DECT). Sixty-two patients underwent CT cardiac examination with a Somatom Definition Flash DECT using tube voltages of 100 kV without filter and 140 kV with a tin filter (mean effective mA s: arterial 72.39 and 62.

Temperature imaging of laser-induced thermotherapy (LITT) by MRI: evaluation of different sequences in phantom.

The purpose of this study was to evaluate magnetic resonance (MR) temperature imaging of the laser-induced thermotherapy (LITT) comparing the proton resonance frequency (PRF) and T 1 thermometry methods. LITT was applied to a liver-mimicking acrylamide gel phantom. Temperature rise up to 70 °C was measured using a MR-compatible fiber-optic thermometer.

Repetitive chemoembolization of hypovascular liver metastases from the most common primary sites.

Aim: To evaluate tumor response in patients with hypovascular liver metastases from the most common primary sites treated with chemoembolization.

Materials & Methods: Chemoembolization was performed in 190 patients (five groups) who had hypovascular liver metastases from the colon (n = 66), breast (n = 40), uveal malignant melanoma (n = 20), pancreas (n = 48) and stomach (n = 16). Surgical resection of primary sites had been performed for all included patients.

Dual-source 128-slice MDCT neck: radiation dose and image quality estimation of three different protocols.

Purpose: To estimate the radiation dose and image quality of single-source (SSCT), high-pitch (HPCT), and dual-energy (DECT) protocols of a dual-source CT (DSCT) system for the examination of neck.

Materials And Methods: 180 patients were randomized to one of the three protocols: 60 patients (age: 55.4 ± 12 years; range: 44-84 years) were examined with a SSCT, other 60 (59.

Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy.

Objective: Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems.

Methods: A total of 126 patients were examined using three XVI systems (groups 1-3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF).

Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT.

Purpose: To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation.

Materials And Methods: Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.

Effect of contrast material on image noise and radiation dose in adult chest computed tomography using automatic exposure control: a comparative study between 16-, 64- and 128-slice CT.

Purpose: To determine the difference in radiation dose between non-enhanced (NECT) and contrast-enhanced (CECT) chest CT examinations contributed by contrast material with different scanner generations with automatic exposure control (AEC).

Methods & Materials: Each 42 adult patients received a NECT and CECT of the chest in one session on a 16-, 64- or 128-slice CT scanner with the same scan protocol settings. However, AEC technology (Care Dose 4D, Siemens) underwent upgrades in each of the three scanner generations.