Adaptive assessment based on fractional CBCT images for cervical cancer.

Purpose: Anatomical and other changes during radiotherapy will cause inaccuracy of dose distributions, therefore the expectation for online adaptive radiation therapy (ART) is high in effectively reducing uncertainties due to intra-variation. However, ART requires extensive time and effort. This study investigated an adaptive assessment workflow based on fractional cone-beam computed tomography (CBCT) images.

Dosimetric comparison of coplanar and noncoplanar volumetric modulated arc therapy for hippocampal-sparing whole-brain radiation therapy.

Whole brain radiation therapy with hippocampal-sparing (HS-WBRT) is a novel treatment of brain metastases, which can relieve symptoms reduce recurrence in the central nervous system, and spare the hippocampus without compromising target coverage. This study aims to find out the superior combination of the treatment planning system and linear accelerator between Eclipse (version 15.6) with TrueBeam and uRT-TPOIS (vision R001.

Dosimetric comparison of deformable image registration and synthetic CT generation based on CBCT images for organs at risk in cervical cancer radiotherapy.

Objective: Anatomical variations existing in cervical cancer radiotherapy treatment can be monitored by cone-beam computed tomography (CBCT) images. Deformable image registration (DIR) from planning CT (pCT) to CBCT images and synthetic CT (sCT) image generation based on CBCT are two methods for improving the quality of CBCT images. This study aims to compare the accuracy of these two approaches geometrically and dosimetrically in cervical cancer radiotherapy.

A Comparison Study Between CNN-Based Deformed Planning CT and CycleGAN-Based Synthetic CT Methods for Improving iCBCT Image Quality.

Purpose: The aim of this study is to compare two methods for improving the image quality of the Varian Halcyon cone-beam CT (iCBCT) system through the deformed planning CT (dpCT) based on the convolutional neural network (CNN) and the synthetic CT (sCT) generation based on the cycle-consistent generative adversarial network (CycleGAN).

Methods: A total of 190 paired pelvic CT and iCBCT image datasets were included in the study, out of which 150 were used for model training and the remaining 40 were used for model testing. For the registration network, we proposed a 3D multi-stage registration network (MSnet) to deform planning CT images to agree with iCBCT images, and the contours from CT images were propagated to the corresponding iCBCT images through a deformation matrix.

A modified delineation method of para-aortic nodal clinical target volume in patients with locally advanced cervical cancer.

Purpose: To validate the nodal center coverage (NCC) of the three mainstream delineation methods of para-aortic nodal clinical target volume (CTV) and propose a modified delineation method of para-aortic nodal CTV in prophylactic extended-field irradiation (EFI) of cervical cancer.

Methods: A total of 106 patients with para-aortic lymph nodes (PALNs) identified on PET/CT were included at Peking Union Medical College Hospital between 2011 and 2020. PALNs were classified as left lateral para-aortic (LLPA), aorto-caval (AC), and right para-caval (RPC).

Higher Dose to Organs at Risk: The Unintended Consequences of Intravenous Contrast Use in Computed Tomography Simulation for Cervical Cancer.

Purpose: To compare the volumes of interest and doses to the organs at risk on contrast and noncontrast scans in patients with cervical cancer who underwent prophylactic extended-field radiation therapy (EFRT).

Methods And Materials: We reviewed twenty cervical cancer patients treated with prophylactic EFRT at Peking Union Medical College Hospital between March 2021 and April 2021. Each patient underwent noncontrast and contrast scans during simulation.

Reliability of Radiomic Features Across Multiple Abdominal CT Image Acquisition Settings: A Pilot Study Using ACR CT Phantom.

We studied the reliability of radiomic features on abdominal computed tomography (CT) images reconstructed with multiple CT image acquisition settings using the ACR (American College of Radiology) CT Phantom. Twenty-four sets of CT images of the ACR CT phantom were attained from a GE Discovery 750HD scanner using 24 different image acquisition settings, combinations of 4 tube currents (25, 50, 100, 200 Effective mAs), 3 slice thicknesses (1.25, 2.

Mumps caused by paraquat-induced poisoning: A case report.

Paraquat (PQ) is a highly toxic herbicide that harms the liver, kidney, lungs and heart, and results in a variety of complications. The majority of patients with severe PQ poisoning may succumb to multiple organ failure, and the mortality rate is high. Although a large number of studies have been performed investigating PQ poisoning, cases of mumps caused by PQ-induced poisoning are rare.

Volumetry of low-contrast liver lesions with CT: Investigation of estimation uncertainties in a phantom study.

Purpose: To evaluate the performance of lesion volumetry in hepatic CT as a function of various imaging acquisition parameters.

Methods: An anthropomorphic abdominal phantom with removable liver inserts was designed for this study. Two liver inserts, each containing 19 synthetic lesions with varying diameter (6-40 mm), shape, contrast (10-65 HU), and both homogenous and mixed-density were designed to have background and lesion CT values corresponding to arterial and portal-venous phase imaging, respectively.

A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube.

Purpose: To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube.

Methods: A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other.

Establishing a threshold for 131I bioassay in nuclear medicine personnel.

Since the late 1970's, manufacturers in nuclear medicine have reformulated the I solution to reduce the volatility of the iodine. There has also been an increase in use of the iodide in encapsulated form. Per the requirement of the current U.

GafChromic XR-QA film in testing panoramic dental radiography.

The location and field size of the incident X-ray beam in panoramic dental radiography cannot be ascertained visually most of the time. However, these parameters are needed for quality control and dosimetry determination. To alleviate this problem, we tested GafChromic XR-QA film on two panoramic systems.

Controlled synthesis of rod-like LiVMoO(6) nanocrystals for application in lithium-ion batteries.

This paper reports a newly developed method for the shape and size control of transition metal composite oxides, such as LiVMoO(6), to obtain significantly enhanced electrode properties for lithium-ion batteries. Rod-like LiVMoO(6) nanocrystals were synthesized through a designed route of partial reduction, self-assembly and re-oxidation. V(5+) and Mo(6+) ions were used with low-grade starting materials to get a mixed valence of V and Mo.