Evaluation of a novel phantom for the quality assurance of a six-degree-of-freedom couch 3D-printed at multiple centres

This study aimed to validate a bespoke 3D-printed phantom for use in quality assurance (QA) of a 6 degrees-of-freedom (6DoF) treatment couch. A novel phantom design comprising a main body with internal cube structures, was fabricated at five centres using Polylactic Acid (PLA) material, with an additional phantom produced incorporating a PLA-stone hybrid material. Correctional setup shifts were determined using image registration by 3D-3D matching of high HU cube structures between obtained cone-beam computer tomography (CBCT) images to reference CTs, containing cubes with fabricated rotational offsets of 3.5°, 1.5° and −2.5° in rotation, pitch, and roll, respectively. Average rotational setup shifts were obtained for each phantom. The reproducibility of 3D-printing was probed by comparing the internal cube size as well as Hounsfield Units between each of the uniquely produced phantoms. For the five PLA phantoms, the average rot, pitch and roll correctional differences from the fabricated offsets were −0.3 ± 0.2°, −0.2 ± 0.5° and 0.2 ± 0.3° respectively, and for the PLA hybrid these differences were −0.09 ± 0.14°, 0.30 ± 0.00° and 0.03 ± 0.10°. There was found to be no statistically significant difference in average cube size between the five PLA printed phantoms, with the significant difference (P < 0.05) in HU of one phantom compared to the others attributed to setup choice and material density. This work demonstrated the capability producing a novel 3D-printed 6DoF couch QA phantom design, at multiple centres, with each unique model capable of sub-degree couch correction

Creating a 3D-printed pelvic phantom to explore the impact of Magnetic Resonance (MR) scanner noise in radiomics analysis, a technical note.

Reproducibility of radiomics features necessitates that scanner noise be considered prior to feature extraction. Phantom research provides the opportunity for such ‘ground truth’ measurements, without the additional complication of patient-related factors. The aim of this technical note was to create a 3D printed Magnetic Resonance Imaging (MRI)-compatible pelvic phantom that can be used for subsequent analysis of the impact of scanner noise on the reproducibility of radiomics features.A 3D printed phantom of a male pelvis was created using fused deposition modelling technology. It was 3D printed using the high density MRI-compatible acrylonitrile butadiene styrene (ABS). The ‘negative’ mould created was then filled with silicone, and the prostate gland and femoral heads were also simulated.We successfully created an MRI-compatible 3D printed pelvic phantom, with a test scan. The phantom will subsequently be utilised to determine the impact of MRI scanner noise on radiomics feature reproducibility

Systemic IL-1β production as a consequence of corneal HSV-1 infection-contribution to the development of herpes simplex keratitis

This study sought to identify potential therapeutic targets in herpes simplex keratitis (HSK) patients with active and inactive infection by investigating peripheral cytokine production. Peripheral blood mononuclear cells (PBMCs) and serum were prepared from healthy controls and HSK patients during active infection or following treatment (inactive infection). Serum antibody titres were determined by ELISA. Protein expression levels were analysed by Western blot. Cytokine levels were determined by multiplex ELISA. Active corneal herpes simplex virus type 1 (HSV-1) infection resulted in significantly elevated peripheral levels of IL-1β in HSK patients compared to healthy controls, and remained significantly increased following treatment. Elevated production of IL-1β in inactive patients was associated with significantly increased levels of IRF3 and STAT1, key proteins involved in promoting anti-viral immune responses. Our data suggest that inflammation persists beyond the period that it is clinically evident and that enhanced peripheral production of IL-1β may have implications for HSV-1 viral clearance in active and inactive HSK patients