Patient positioning in minimally invasive gynecologic surgery: strategies to prevent injuries and improve outcomes.

Effective patient positioning is a critical factor influencing surgical outcomes, mainly in minimally invasive gynecologic surgery (MIGS) where precise positioning facilitates optimal access to the surgical field. This paper provides a comprehensive exploration of the significance of strategic patient placement in MIGS, emphasizing its role in preventing intraoperative injuries and enhancing overall surgical success. The manuscript addresses potential complications arising from suboptimal positioning and highlights the essential key points for appropriate patient positioning during MIGS, encompassing what the surgical team should or shouldn't do. In this perspective, the risk factors associated with nerve injuries, sliding, compartment syndrome, and pressure ulcers are outlined to guide clinical practice. Overall, this paper underscores the critical role of precise patient positioning in achieving successful MIGS procedures and highlights key principles for the gynecological team to ensure optimal patient outcomes.

PIAA: Pre-imaging all-round assistant for digital radiography.

BACKGROUND: In radiography procedures, radiographers' suboptimal positioning and exposure parameter settings may necessitate image retakes, subjecting patients to unnecessary ionizing radiation exposure. Reducing retakes is crucial to minimize patient X-ray exposure and conserve medical resources. OBJECTIVE: We propose a Digital Radiography (DR) Pre-imaging All-round Assistant (PIAA) that leverages Artificial Intelligence (AI) technology to enhance traditional DR. METHODS: PIAA consists of an RGB-Depth (RGB-D) multi-camera array, an embedded computing platform, and multiple software components. It features an Adaptive RGB-D Image Acquisition (ARDIA) module that automatically selects the appropriate RGB camera based on the distance between the cameras and patients. It includes a 2.5D Selective Skeletal Keypoints Estimation (2.5D-SSKE) module that fuses depth information with 2D keypoints to estimate the pose of target body parts. Thirdly, it also uses a Domain expertise (DE) embedded Full-body Exposure Parameter Estimation (DFEPE) module that combines 2.5D-SSKE and DE to accurately estimate parameters for full-body DR views. RESULTS: Optimizes DR workflow, significantly enhancing operational efficiency. The average time required for positioning patients and preparing exposure parameters was reduced from 73 seconds to 8 seconds. CONCLUSIONS: PIAA shows significant promise for extension to full-body examinations.

Effect of body position during weaning from total liquid ventilation in piglets.

OBJECTIVE: To determine if change in body position improves oxygen requirements and respiratory mechanics during the transition from total liquid ventilation (TLV) to gas ventilation. METHODS: Fourteen piglets underwent TLV, followed by a 2-hour weaning period under conventional gas ventilation. Subjects were randomized to the experimental group (Rotating - R), that was in prone position between the 10th and 30th minute of weaning, or to the static control group (Supine - S). RESULTS: Oxygenation index was lower in the R group at 30 minutes in prone position than that in the S group (1.9 [1.6; 2.8] vs 3.5 [3.1; 5.1], p = 0.001). This difference disappeared when subjects resumed the supine position (4.2 [3.8; 4.7] and 4.7 [3.8; 5.4], p = 0.4, for the R and S groups, respectively). The change in body position did not affect respiratory system compliance or inspiratory capacity. CONCLUSION: Prone position improved oxygenation during weaning from TLV. The effect disappeared once piglets returned to the supine position.

Study protocol: Optimising patient positioning for the planning of accelerated partial breast radiotherapy for the integrated magnetic resonance linear accelerator: OPRAH MRL.

BACKGROUND: Accelerated partial breast irradiation (APBI) is an accepted treatment option for early breast cancer. Treatment delivered on the Magnetic Resonance integrated Linear Accelerator (MRL) provides the added assurance of improved soft tissue visibility, important in the delivery of APBI. This technique can be delivered in both the supine and prone positions, however current literature suggests that prone treatment on the MRL is infeasible due to physical limitations with bore size. This study aims to investigate the feasibility of positioning patients on a custom designed prone breast board compared with supine positioning on a personalised vacuum bag. Geometric distortion, the relative position of Organs at Risk (OAR) to the tumour bed and breathing motion (intrafraction motion) will be compared between the supine and prone positions. The study will also investigate the positional impact on dosimetry, patient experience, and position preference. METHODS: Up to 30 patients will be recruited over a 12-month period for participation in this Human Research Ethics Committee approved exploratory cohort study. Patients will be scanned on the magnetic resonance imaging (MRI) Simulator in both the supine and prone positions as per current standard of care for APBI simulation. Supine and prone positioning comparisons will all be assessed on de-identified MRI image pairs, acquired using appropriate software. Patient experience will be explored through completion of a short, anonymous electronic survey. Descriptive statistics will be used for reporting of results with categorical, parametric/non-parametric tests applied (data format dependent). Survey results will be interpreted by comparison of percentage frequencies across the Likert scales. Thematic content analysis will be used to interpret qualitative data from the open-ended survey questions. DISCUSSION: The results of this study will be used to assess the feasibility of treating patients with APBI in the prone position on a custom designed board on the MRL. It may also be used to assist with identification of patients who would benefit from this position over supine without the need to perform both scans. Patient experience and technical considerations will be utilised to develop a tool to assist in this process. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN1262400067583. Registered 28th of May 2024. https://www.anzctr.org.au/ACTRN12624000679583.aspx.

Virtual reality simulation for mastery learning of wrist radiograph technique.

INTRODUCTION: Virtual reality (VR) simulation is a technology that empowers students and radiographers to practice radiography in a virtual environment that resembles real-life clinical scenarios. The purpose of this randomised study was to examine the relationship between clinical specialty and the ability to assess and obtain a lateral wrist radiograph using a VR simulator. METHODS: Radiographers and radiography students were recruited from the EFRS Research Hub at the 2024 European Congress of Radiology. After completing a background questionnaire, participants entered a VR simulator where they assessed lateral wrist radiographs and, if necessary, attempted a retake. Fisher's exact test was used to evaluate the relationship between specialties and participants' ability to assess positioning and perform retakes. Rank-biserial correlation estimated the relationship between participants' ability to reposition the VR patient and their VR experience and self-perceived confidence in wrist radiograph positioning. RESULTS: The cohort included 173 participants from 14 specialties across 21 countries. There was a borderline significant trend between clinical specialty and correct positioning assessment (p = 0.052) and between self-perceived confidence in acquiring wrist radiographs and repositioning for a retake (p = 0.052). Neither clinical specialty (p = 0.480) nor previous VR experience (p = 0.409) correlated with ability to reposition for a retake. CONCLUSION: While results indicated a potential correlation between participants' ability to position a VR patient and both clinical specialty and confidence in wrist radiography, these trends were not statistically significant. Nevertheless, the findings suggest that VR holds promise for radiography training, though further research is necessary to explore the factors that influence performance and learning. IMPLICATIONS FOR PRACTICE: The incorporation of VR technology into standard radiography training programs could potentially improve patient outcomes by ensuring that radiography students are more skilled at acquiring quality radiographs prior to their first clinical practice. It should be noted though, that knowledge on positioning criteria and anatomy is an advantage when practicing correct positioning in a VR simulator.

Oral Care and Positioning to Prevent Ventilator-Associated Pneumonia: A Systematic Review.

Introduction: Ventilator-associated pneumonia (VAP) is one of the most common nosocomial infections in critical patients. The negative impacts of VAP on patient outcomes emphasize the importance of effective preventive measures such as oral care and patient positioning. The aim of this review was to investigate the impact of oral care and positioning on the prevention of VAP among patients in the intensive care unit. Methods: This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed. The methodological quality of included studies was appraised using Joanna Briggs Institute checklists. Results: In total 13 studies were included, all of them were randomized controlled trials. Six out of nine studies about oral care have significant results on VAP incidence. Regarding the position, Patients positioned at a 45-degree were less likely to develop VAP than those positioned at a 30-degree and those in a supine position. Conclusion: Although patients positioned at 45-degree angle were less likely to develop VAP than those at 30-degree, it is necessary to individualize this practice before recommending it, once there are some contraindications, such as neurocritical patients. Regarding oral care to prevent VAP, considering the current guidelines' recommendation not to use oral chlorexidine, further studies evaluating alternatives are needed.

Unilateral Compressive Peroneal Neuropathy in Intensive Care Settings During the COVID-19 Pandemic: A Series of Three Cases.

Peroneal nerve entrapment, typically associated with behaviors like cross-legged sitting or squatting, can also occur from extended periods of lying down where the lower limbs usually assume a position of hip external rotation and knee flexion. In such positions, the fibular head's prominence can exert sustained pressure on the peroneal nerve. We report three cases of unilateral peroneal neuropathy in intensive care unit (ICU) patients during the coronavirus disease (COVID-19) pandemic, highlighting the possible role of prolonged supine or lateral decubitus positions in the development of this condition. Electrophysiological studies confirmed peroneal nerve palsy in all cases, with two patients achieving full recovery, while the third required a permanent ankle foot orthosis for mobility due to a lack of neurological recovery. The COVID-19 pandemic has challenged ideal nursing care, including in ICU settings, leading to suboptimal nursing care standards and compromised frequent positioning regimes.

Efficacy of D33 Sealed Foam in Preventing Skin Injury from Surgical Positioning: Randomized Clinical Trial.

Objective: To evaluate the efficacy of density-33 (D33) sealed foam in preventing skin injuries from surgical positioning. Approach: The study, reported according to the Consolidated Standards of Reporting Trials, is characterized as a randomized clinical trial, double mask, with 64 adult patients undergoing elective surgery, 35 allocated to the control group (CG), positioned on a conventional surgical table, and 29 to the experimental group (EG), positioned on a conventional surgical table overlaid with a D33 sealed foam support surface (SS) in the occipital, sacral, and heel regions. Simple randomization was carried out, as was masking of the researcher who evaluated the skin of the patient and the statistician. Data collection was carried out immediately preoperatively, intraoperatively, and postoperatively until the third day or until patient discharge. Statistical analysis included measures of association in contingency tables, χ2, and relative risk to compare the incidence of injuries between groups. Results: Skin injuries were greater in the CG, with blanchable erythema being the main injury. The use of D33 sealed foam reduced the incidence of injury in the EG by 61.2% (relative risk: 0.39; 95% confidence interval: 0.220-0.684; p < 0.001). Innovation: One of the first clinical studies to demonstrate that using a D33 sealed foam SS decreased the incidence of blanchable erythema from surgical positioning. Conclusion: D33 sealed foam was effective in preventing skin injury from surgical positioning in patients undergoing elective surgeries.

Facedown Positioning in Macular Hole Surgery: A Systematic Review and Individual Participant Data Meta-Analysis.

TOPIC: To assess the anatomic and visual effects of facedown positioning (FDP) advice in patients undergoing vitrectomy with gas tamponade for idiopathic full-thickness macular holes (FTMHs) and to explore differential treatment effects by macular hole size and FDP duration. CLINICAL RELEVANCE: The necessity and duration of FDP for FTMH closure remain contentious, with no consensus guidelines. METHODS: Prospectively registered systematic review and individual patient data (IPD) meta-analysis of randomized controlled trials comparing FDP with no FDP (nFDP) across the MEDLINE, Embase, and Cochrane Library databases and clinical trial registries from January 2000 to March 2023 (CRD42023395152). All adults with idiopathic FTMHs undergoing vitrectomy with gas tamponade were included. The main outcomes were primary macular hole closure and postoperative visual acuity at 6 months or nearest time point. RESULTS: Of 8 eligible trials, 5 contributed IPD for 379 eyes and were included in our analysis. The adjusted odds ratio (OR) for primary closure with FDP versus nFDP was 2.41 (95% confidence interval [CI], 0.98-5.93, P = 0.06; low-certainty evidence), translating to a risk ratio (RR) of 1.08 (1.00-1.11) and a number needed to treat (NNT) of 15. The FDP group exhibited a mean improvement in postoperative visual acuity of -0.08 logarithm of the minimum angle of resolution (logMAR) (-0.13 to -0.02, P = 0.006; low-certainty evidence) compared with the nFDP group. Benefits were more certain in participants with larger holes of minimum linear diameter ≥ 400 µm: adjusted OR for closure ranged from 1.13 to 10.12 (P = 0.030) (NNT 12), with a mean visual acuity improvement of -0.18 to -0.01 logMAR (P = 0.022). Each additional day of FDP was associated with improved odds of anatomic success (adjusted OR, 1.02-1.41, RR, 1.00-1.02, P = 0.026) and visual acuity improvement (-0.02 logMAR, -0.03 to -0.01, P = 0.002), possibly plateauing at 3 days. CONCLUSIONS: This study provides low-certainty evidence that FDP improves the anatomic and visual outcomes of macular hole surgery modestly and indicates that the effect may be more substantial for macular holes exceeding 400 µm. The findings support recommending FDP for patients with macular holes exceeding 400 µm pending further investigation. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Ramped versus sniffing position for Ambu® AuraGainTM insertion in patients with obesity: a randomized controlled study.

BACKGROUND: The ramped position facilitates mask ventilation and endotracheal intubation in patients with obesity. This study aimed to determine whether the ramped position improves supraglottic airway (SGA) insertion in patients with obesity. METHODS: In this prospective, randomized, single-center trial, 48 obese patients undergoing elective surgery were randomized into either ramped or sniffing position groups. The Ambu® AuraGainTM (Ambu A/S), a second-generation SGA, was used. The primary outcome was the time required for the AuraGain insertion. Secondary outcomes included ease and number of insertion attempts, oropharyngeal leak pressure (OLP), and complications. The number needed to treat (NNT) was calculated to ensure ease of insertion. RESULTS: The time required for the AuraGain insertion was significantly shorter in the ramped group than in the sniffing group (13.0 [11.0, 16.0] vs. 24.0 [21.0, 28.0], P < 0.001). The insertion was easier in the ramped group than in the sniffing group (23/24 vs. 13/24, NNT = 2.4 [95% CI, 1.6, 5.0], P = 0.003). The first-attempt success rate was higher in the ramped group than in the sniffing group, although the difference was not statistically significant (22/24 vs. 18/24, P = 0.319). The OLP and postoperative complication rates were not significantly different between the groups. CONCLUSIONS: The ramped position reduced the time required for the AuraGain insertion in obese patients while providing comparable airway sealing without increasing adverse events. Therefore, a ramped position may be a more suitable option for SGA insertion in this population.

Surface-guided radiotherapy systems in locoregional deep inspiration breath hold radiotherapy for breast cancer - a multicenter study on the setup accuracy.

Background: Daily image-guided radiotherapy (IGRT) and deep inspiration breath hold (DIBH) technique are recommended for locoregional RT of breast cancer. The optimal workflow for a combination of surface-guided RT (SGRT) with DIBH technique is of current clinical interest. Materials and methods: The setup accuracy at three hospitals was evaluated using different SGRT workflows. A total of 150 patients (2269 image pairs) were analyzed in three groups: patient setup with the AlignRT® SGRT system in Tampere (Site 1, n = 50), the Catalyst™ SGRT system in Turku (Site 2, n = 50) and the Catalyst™ SGRT system in Jönköping (Site 3, n = 50). Each site used their routine workflow with SGRT-based setup and IGRT positioning. Residual errors of the bony chest wall, thoracic vertebra (Th 1) and humeral head were evaluated using IGRT images. Results: Systematic residual errors in the cranio-caudal (CC) direction and in pitch were generally larger at Site 2 than those at Sites 1 and 3 (p = 0.01-0.7). With daily IGRT, only a small difference (p = 0.01-0.9) was observed in residual random errors of bony structures in other directions between sites. Conclusion: The introduction of SGRT and the use of daily IGRT lead to small residual errors when combining the best workflow practices from different hospitals. Our multicenter evaluation led to improved workflow by tightening the SGRT tolerances on Site 2 and fixation modification. Because of mainly small random errors, systematic posture errors in the images need to be corrected after posture correction with new setup surfaces. We recommend tight SGRT tolerances, good fixation and correction of systematic errors.

Impact of the spatial orientation of the patient's head, metal artifact reduction, and tube current on cone-beam computed tomography artifact expression adjacent to a dental implant: A laboratory study using a simulated surgical guide.

Purpose: The aim of this study was to evaluate image artifacts in the vicinity of dental implants in cone-beam computed tomography (CBCT) scans obtained with different spatial orientations, tube current levels, and metal artifact reduction algorithm (MAR) conditions. Materials and Methods: One dental implant and 2 tubes filled with a radiopaque solution were placed in the posterior region of a mandible using a surgical guide to ensure parallel alignment. CBCT scans were acquired with the mandible in 2 spatial orientations in relation to the X-ray projection plane (standard and modified) at 3 tube current levels: 5, 8, and 11 mA. CBCT scans were repeated without the implant and were reconstructed with and without MAR. The mean voxel and noise values of each tube were obtained and compared using multi-way analysis of variance and the Tukey test (α=0.05). Results: Mean voxel values were significantly higher and noise values were significantly lower in the modified orientation than in the standard orientation (P<0.05). MAR activation and tube current levels did not show significant differences in most cases of the modified spatial orientation and in the absence of the dental implant (P>0.05). Conclusion: Modifying the spatial orientation of the head increased brightness and reduced spatial orientation noise in adjacent regions of a dental implant, with no influence from the tube current level and MAR.

Surgical Tips: Managing the Orthopedic Traction Table on Gritti-Stokes Amputated Patients.

Introduction: Closed anatomical reduction of per-trochanteric fractures requires 3-axis control of the orthopedic traction table (OTT) which is challenging in patients having suffered a previous ipsilateral Gritti-Stokes amputation. Case Report: A 52-year-old man, known by Gritti-Stokes amputated (GSA) 10 years before, was admitted to our trauma center after a fall from his height. We describe a simple method for positioning a previously ipsilateral GSA patient in an OTT to reduce displaced a femoral per-trochanteric fracture site and to maintain it during surgery. The proposed method attaches non-adhesive bands to the stump, reinforced by the wire guide package to increase rigidity and allow 3-axis control of the OTT. Conclusion: This method can be performed in a standard trauma operating room, it only uses materials that were planned to be used during surgery, and consequently, it does not increase operative costs.

Guideline on positioning and early mobilisation in the critically ill by an expert panel.

A scientific panel was created consisting of 23 interdisciplinary and interprofessional experts in intensive care medicine, physiotherapy, nursing care, surgery, rehabilitative medicine, and pneumology delegated from scientific societies together with a patient representative and a delegate from the Association of the Scientific Medical Societies who advised methodological implementation. The guideline was created according to the German Association of the Scientific Medical Societies (AWMF), based on The Appraisal of Guidelines for Research and Evaluation (AGREE) II. The topics of (early) mobilisation, neuromuscular electrical stimulation, assist devices for mobilisation, and positioning, including prone positioning, were identified as areas to be addressed and assigned to specialist expert groups, taking conflicts of interest into account. The panel formulated PICO questions (addressing the population, intervention, comparison or control group as well as the resulting outcomes), conducted a systematic literature review with abstract screening and full-text analysis and created summary tables. This was followed by grading the evidence according to the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence and a risk of bias assessment. The recommendations were finalized according to GRADE and voted using an online Delphi process followed by a final hybrid consensus conference. The German long version of the guideline was approved by the professional associations. For this English version an update of the systematic review was conducted until April 2024 and recommendation adapted based on new evidence in systematic reviews and randomized controlled trials. In total, 46 recommendations were developed and research gaps addressed.

Effects of axial loading and positions on lumbar spinal stenosis: an MRI study using a new axial loading device.

OBJECTIVE: A new axial loading device was used to investigate the effects of axial loading and positions on lumbar structure and lumbar spinal stenosis. METHODS: A total of 40 patients sequentially underwent 4 examinations: (1) the psoas-relaxed position MRI, (2) the extended position MRI, (3) the psoas-relaxed position axial loading MRI, (4) the extended position axial loading MRI. The dural sac cross-sectional area, sagittal vertebral canal diameter, disc height and ligamentum flavum thickness of L3-4, L4-5, L5-S1 and lumbar lordosis angle were measured and compared. A new device with pneumatic shoulder-hip compression mode was used for axial loading. RESULTS: In the absence of axial loading, there was a significant reduction in dural sac cross-sectional area with extension only seen at the L3-4 (p = 0.033) relative to the dural sac area in the psoas-relaxed position. However, with axial loading, there was a significant reduction in dural sac cross-sectional area at all levels in both psoas-relaxed (L3-4, p = 0.041; L5-S1, p = 0.005; L4-5, p = 0.002) and extension (p < 0.001) positions. The sagittal vertebral canal diameter and disc height were significantly reduced at all lumbar levels with axial loading and extension (p < 0.001); however, in psoas-relaxed position, the sagittal vertebral canal diameter was only reduced with axial loading at L3-4 (p = 0.018) and L4-5 (p = 0.011), and the disc height was reduced with axial-loading at all levels (L3-4, p = 0.027; L5-S1, p = 0.001; L4-5, p < 0.001). The ligamentum flavum thickness and lumbar lordosis in extension position had a statistically significant increase compared to psoas-relaxed position with or without axial loading (p < 0.001). CONCLUSION: Both axial loading and extension of lumbar may exacerbate lumbar spinal stenosis. Axial loading in extension position could maximally aggravate lumbar spinal stenosis, but may cause some patients intolerable. For those patients, axial loading MRI in psoas-relaxed position may be a good choice.

Compliance of volunteers in a fully-enclosed patient rotation system for MR-guided radiation therapy: a prospective study.

BACKGROUND: Particle therapy makes a noteworthy contribution in the treatment of tumor diseases. In order to be able to irradiate from different angles, usually expensive, complex and large gantries are used. Instead rotating the beam via a gantry, the patient itself might be rotated. Here we present tolerance and compliance of volunteers for a fully-enclosed patient rotation system in a clinical magnetic resonance (MR)-scanner for potential use in MR-guided radiotherapy, conducted within a prospective evaluation study. METHODS: A patient rotation system was used to simulate and perform magnetic resonance imaging (MRI)-examinations with 50 volunteers without an oncological question. For 20 participants, the MR-examination within the bore was simulated by introducing realistic MRI noise, whereas 30 participants received an examination with image acquisition. Initially, body parameters and claustrophobia were assessed. The subjects were then rotated to different angles for simulation (0°, 45°, 90°, 180°) and imaging (0°, 70°, 90°, 110°). At each angle, anxiety and motion sickness were assessed using a 6-item State-Trait-Anxiety-Inventory (STAI-6) and a modified Motion Sickness Assessment Questionnaire (MSAQ). In addition, general areas of discomfort were evaluated. RESULTS: Out of 50 subjects, three (6%) subjects terminated the study prematurely. One subject dropped out during simulation due to nausea while rotating to 45°. During imaging, further two subjects dropped out due to shoulder pain from positioning at 90° and 110°, respectively. The average result for claustrophobia (0 = no claustrophobia to 4 = extreme claustrophobia) was none to light claustrophobia (average score: simulation 0.64 ± 0.33, imaging 0.51 ± 0.39). The mean anxiety scores (0% = no anxiety to 100% = maximal anxiety) were 11.04% (simulation) and 15.82% (imaging). Mean motion sickness scores (0% = no motion sickness to 100% = maximal motion sickness) of 3.5% (simulation) and 6.76% (imaging) were obtained across all participants. CONCLUSION: Our study proves the feasibility of horizontal rotation in a fully-enclosed rotation system within an MR-scanner. Anxiety scores were low and motion sickness was only a minor influence. Both anxiety and motion sickness showed no angular dependency. Further optimizations with regard to immobilization in the rotation device may increase subject comfort.

A prospective observational study evaluating two patient immobilisation methods in lung stereotactic radiotherapy.

PURPOSE: The main objective of this study was to assess inter- and intrafraction errors for two patient immobilisation devices in the context of lung stereotactic body radiation therapy: a vacuum cushion and a simple arm support. MATERIALS AND METHODS: Twenty patients who were treated with lung stereotactic body radiation therapy in supine position with arms above their head were included in the study. Ten patients were setup in a vacuum cushion (Bluebag™, Elekta) and ten other patients with a simple arm support (Posirest™, Civco). A pretreatment four-dimensional cone-beam computed tomography and a post-treatment three-dimensional cone-beam computed tomography were acquired to compare positioning and immobilisation accuracy. Based on a rigid registration with the planning computed tomography on the spine at the target level, translational and rotational errors were reported. RESULTS: The median number of fractions per treatment was 5 (range: 3-10). Mean interfraction errors based on 112 four-dimensional cone-beam computed tomographies were similar for both setups with deviations less than or equal to 1.3mm in lateral and vertical direction and 1.2° in roll and yaw. For longitudinal translational errors, mean interfraction errors were 0.7mm with vacuum cushion and -3.9mm with arm support. Based on 111 three-dimensional cone-beam computed tomographies, mean lateral, longitudinal and vertical intrafraction errors were -0.1mm, -0.2mm and 0.0mm respectively (SD: 1.0, 1.2 and 1.0mm respectively) for the patients setup with vacuum cushion, and mean vertical, longitudinal and lateral intrafraction errors were -0.3mm, -0.7mm and 0.1mm respectively (SD: 2.3, 1.8 and 1.4mm respectively) for the patients setup with arm support. Intrafraction errors means were not statistically different between both positions but standard deviations were statistically larger with arm support. CONCLUSION: The results of our study showed similar inter and intrafraction mean deviations between both positioning but a large variability in intrafraction observed with arm support suggested a more accurate immobilization with vacuum cushion.

A review on 4D cone-beam CT (4D-CBCT) in radiation therapy: Technical advances and clinical applications.

Cone-beam CT (CBCT) is the most commonly used onboard imaging technique for target localization in radiation therapy. Conventional 3D CBCT acquires x-ray cone-beam projections at multiple angles around the patient to reconstruct 3D images of the patient in the treatment room. However, despite its wide usage, 3D CBCT is limited in imaging disease sites affected by respiratory motions or other dynamic changes within the body, as it lacks time-resolved information. To overcome this limitation, 4D-CBCT was developed to incorporate a time dimension in the imaging to account for the patient's motion during the acquisitions. For example, respiration-correlated 4D-CBCT divides the breathing cycles into different phase bins and reconstructs 3D images for each phase bin, ultimately generating a complete set of 4D images. 4D-CBCT is valuable for localizing tumors in the thoracic and abdominal regions where the localization accuracy is affected by respiratory motions. This is especially important for hypofractionated stereotactic body radiation therapy (SBRT), which delivers much higher fractional doses in fewer fractions than conventional fractionated treatments. Nonetheless, 4D-CBCT does face certain limitations, including long scanning times, high imaging doses, and compromised image quality due to the necessity of acquiring sufficient x-ray projections for each respiratory phase. In order to address these challenges, numerous methods have been developed to achieve fast, low-dose, and high-quality 4D-CBCT. This paper aims to review the technical developments surrounding 4D-CBCT comprehensively. It will explore conventional algorithms and recent deep learning-based approaches, delving into their capabilities and limitations. Additionally, the paper will discuss the potential clinical applications of 4D-CBCT and outline a future roadmap, highlighting areas for further research and development. Through this exploration, the readers will better understand 4D-CBCT's capabilities and potential to enhance radiation therapy.

Comparing the posture and comfort of anaesthesiologists during laryngoscopy and tracheal intubation in the head-elevated laryngoscopy position in supine position and with a 25° backup: A randomised clinical crossover trial.

Background and Aims: The head-elevated laryngoscopy position (HELP) and a 25° backup have been proposed to enhance glottic visualisation, yet concerns about ergonomic discomfort hinder their widespread adoption. This study compares the comfort and posture adopted by anaesthesiologists while performing laryngoscopy and tracheal intubation with patients in HELP while in a supine position or with 25° backup. Methods: The study included 48 patients aged 18-60 years with normal airways and 12 experienced anaesthesiologists. Patients were randomised into two groups using permuted block randomisation. Anaesthesiologists performed laryngoscopy and intubation in supine HELP and 25° backup HELP positions. Anaesthesiologist's posture was determined by measuring the angles of neck, wrist, elbow, back and knee joints, which were compared using Student's t-test, and subjective comfort assessed on a Likert scale was compared using the Chi-square test. As mentioned by the anaesthesiologist, Cormack- Lehane grading was also noted and compared using a Chi-square test between groups, taking a P value <0.05 as significant. Results: Both positions demonstrated comparable anaesthesiologist posture (P = 0.919) and comfort (P = 0.644). However, the 25° backup HELP positions significantly improved Cormack-Lehane grades, with 68% achieving grade 1 compared to 31% in the supine HELP group (P = 0.012). Haemodynamic stability and tracheal intubation time showed no significant differences between the groups (P = 0.475 and 0.117, respectively), and no complications were reported in either group. Conclusion: Anaesthesiologists' posture and comfort during laryngoscopy and tracheal intubation are similar between supine and 25° backup in patients with easy airways.

Efficacy and safety of video double-lumen tube intubation in lateral position in patients undergoing thoracic surgery: a randomized controlled trial.

BACKGROUND: Video double-lumen tube (VDLT) intubation in lateral position is a potential alternative to intubation in supine position in patients undergoing thoracic surgery. This non-inferiority trial assessed the efficacy and safety of VDLT intubation in lateral position. METHODS: Patients (18-70 yr) undergoing right thoracoscopic lung surgery were randomized to either the left lateral position group (group L) or the supine position group (group S). The VDLT was placed under video larygoscopy. The primary endpoint was the intubation time. Secondary endpoints included VDLT displacement rate, intubation failure rate, the satisfaction of surgeon and nurse, and intubation-related adverse events. RESULTS: The analysis covered 80 patients. The total intubation time was 52.0 [20.4]s in group L and 34.3 [13.2]s in group S, with a mean difference of 17.6 s [95% confidence interval (CI): 9.9 s to 25.3 s; P = 0.050], failing to demonstrate non-inferiority with a non-inferiority margin of 10 s. Group L, compared with group S, had significantly lower VDLT displacement rate (P = 0.017) and higher nurse satisfaction (P = 0.026). No intubation failure occurred in any group. Intubation complications (P = 0.802) and surgeon satisfaction (P = 0.415) were comparable between two groups. CONCLUSIONS: The lateral VDLT intubation took longer time than in the supine position, and non-inferiority was not achieved. The incidence of displacement as the secondary endpoint was lower in the L group, possibly due to changing body positions beforehand. The indication of lateral VDLT intubation should be based on a balance between the safety of airway management and the lower incidence of displacement. TRIAL REGISTRATION: The study was registered at Chictr.org.cn with the number ChiCTR2200064831 on 19/10/2022.