Characteristics of detection accuracy of the patient setup using InBore optical patient positioning system.

This study aimed to evaluate the detection accuracy of the AlignRT-InBore system in surface-guided radiation therapy using a phantom and to determine the feasibility of the system by conducting a comparative analysis with cone-beam computed tomography (CBCT) registration. The AlignRT-InBore system integrated with the ETHOS Therapy was used. A phantom and a QUASAR phantom were employed to examine the specific areas of interest relevant to clinical cases.

Short-time-window Patlak imaging using a population-based arterial input function and optimized Bayesian penalized likelihood reconstruction: a feasibility study.

Background: To explore the feasibility of short-time-window Ki imaging using a population-based arterial input function (IF) and optimized Bayesian penalized likelihood (BPL) reconstruction as a practical alternative to long-time-window Ki imaging with an individual patient-based IF. Myocardial Ki images were generated from 73 dynamic F-FDG-PET/CT scans of 30 patients with cardiac sarcoidosis. For each dynamic scan, the Ki images were obtained using the IF from each individual patient and a long time window (10-60 min).

[Basic Research on Comparative Evaluation of Calculated Dose Distribution Using Monte Carlo Algorithm-equipped Treatment Planning Systems in Volumetric Modulated Arc Therapy].

Purpose: The purpose was to study comparative evaluation of calculated dose distribution by X-ray Voxel Monte Carlo (XVMC) for dose calculation in Acuros XB (AXB). The dose commissioning and head and neck volumetric modulated arc therapy (VMAT) clinical cases were compared for AXB in Eclipse and XVMC in Monaco.

Methods: For TrueBeam at 6 MV, we compared the dose commissioning for simple rectangle, heterogeneity correction, and multileaf collimator (MLC) characteristics.

[Evaluation of Stability and Reliability of the Measurement of Absorbed Dose-to-water for an HDR Ir Sandwich Setup Phantom].

Purpose: In this study, we evaluated the stability and reliability of absorbed dose-to-water for an HDR Ir sandwich setup phantom method by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.

Methods: The sandwich setup phantom was designed with a dedicated device for two ion chamber measurements of absorbed dose-to-water for a mHDR-v2r Ir brachytherapy source is presented. To test the reliability of sandwich setup phantom of measurements with absorbed dose-to-water, we were compared with values based on AAPM TG-43 protocol and evaluated temporal variations of the measurement, intra-rater reliability.

Conspicuity of Malignant Liver Tumors on Diffusion-Weighted Imaging With Short tau Inversion Recovery After Gadolinium Ethoxybenzyl Diethylenetriaminepentaacetic Acid Administration.

Background: Diffusion-weighted imaging (DWI) has been used for the detection and characterization of liver tumors because it has excellent contrast resolution. DWI using short tau inversion recovery (STIR) can improve tumor-to-liver contrast after gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) administration that shortens the T relaxation of liver parenchyma.

Purpose: To quantitatively and qualitatively compare the conspicuity of malignant liver tumors on DWI after Gd-EOB-DTPA administration between STIR and chemical shift selective (CHESS) sequences.

Secondary use of hospital information system data for safe bedside radiography in terms of patient factors.

Objective:: The purpose of this study was to use patient data gathered by a hospital information system (HIS) to improve the safe performance of bedside radiography.

Method:: Hierarchical cluster analysis was used to investigate the factors of hospitalised patients who had undergone radiography in the X-ray room or at the bedside. Logistic regression analysis was then performed to quantify patient factors and calculate the probability of undergoing general radiography or bedside radiography.

[A Proposal for Evaluating the Positional Accuracy of Add-on Six-degrees-of-freedom Radiotherapy Couch in Couch Rotation for Image-guided Radiotherapy].

Purpose: In this study, we proposed and evaluated position correction accuracy assessment method with a phantom for IGRT system with add-on six-degrees-of-freedom radiotherapy (6D) couches in couch rotation.

Methods And Materials: A phantom was used in a self-build phantom. We were scanned with computed tomography (CT) for radiotherapy planning and planned treatment isocenter to fall in line with CT center by treatment planning system.

COMPARISON OF THE PERIPHERAL DOSES FROM DIFFERENT IMRT TECHNIQUES FOR PEDIATRIC HEAD AND NECK RADIATION THERAPY.

Intensity-modulated radiation therapy (IMRT) can deliver high and homogeneous doses to the target area while limiting doses to organs at risk. We used a pediatric phantom to simulate the treatment of a head and neck tumor in a child. The peripheral doses were examined for three different IMRT techniques [dynamic multileaf collimator (DMLC), segmental multileaf collimator (SMLC) and volumetric modulated arc therapy (VMAT)].

Investigation of whether in-room CT-based adaptive intracavitary brachytherapy for uterine cervical cancer is robust against interfractional location variations of organs and/or applicators.

This study investigates whether in-room computed tomography (CT)-based adaptive treatment planning (ATP) is robust against interfractional location variations, namely, interfractional organ motions and/or applicator displacements, in 3D intracavitary brachytherapy (ICBT) for uterine cervical cancer. In ATP, the radiation treatment plans, which have been designed based on planning CT images (and/or MR images) acquired just before the treatments, are adaptively applied for each fraction, taking into account the interfractional location variations. 2D and 3D plans with ATP for 14 patients were simulated for 56 fractions at a prescribed dose of 600 cGy per fraction.