Flank versus prone position in percutaneous nephrolithotomy: a meta-analysis of randomized controlled studies.

The objective of this study is to assess the safety and efficacy of the flank position in percutaneous nephrolithotomy (PCNL). We searched PubMed, Embase, SCOPUS, the Cochrane database libraries, and the Chinese Biomedical Literature Database, and randomized controlled trials (RCTs) assessing PCNL in flank position are included in this meta-analysis. The related trials met the inclusion criteria were analyzed using RevMan 5.4. Seven randomized controlled trials were included, involving a total of 587 patients. We found that there was a lower decrease in hemoglobin levels in the flank position group compared to prone-position group (mean difference [MD] = - 0.15, 95% confidence interval (CI) - 0.22 to - 0.08, P < 0.00001). Moreover, our meta-analysis demonstrated no significant differences between groups regarding stone-free rate (relative risk [RR] = 1.00, 95% CI 0.93 to 1.06, P = 0.92), operative time(MD = 0.76, 95% CI - 5.31 to 6.83, P < 0.00001), hospital stay (MD = 0.03, 95% CI - 0.32 to 0.32, P < 0.00001), and complications Clavien grade I (RR = 1.01, 95% CI 0.98 to 1.05, P = 0.54), Clavien grade II (RR = 1, 95% CI 0.97 to 1.02, P = 0.78), and Clavien grade III (RR = 1, 95% CI 0.98 to 1.03, P = 0.77). The use of flank position for PCNL is associated with reduced hemoglobin change without an increase in complications. This positioning technique can be considered safe for patients with nephrolithiasis and may be particularly suitable for high-risk individuals such as those who are obese or have decreased cardiopulmonary function. However, further randomized trials are needed to confirm these findings.

Body Positions Alter Hemodynamics and Respiration in Healthy Adults: A Systematic Review and Meta-Analysis.

Objective Different body positions can exert both positive and negative physiological effects on hemodynamics and respiration. This study aims to conduct a literature review and examine hemodynamic and respiratory alterations to different body positions.Methods The study protocol was registered with the International Prospective Registry of Systematic Reviews (register no. CRD42021291464). Two independent reviewers evaluated the methodological quality of all included studies using the Down and Black checklist, while the quality of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach. The overall effects of different body positions were reported from random effects meta-analysis.Results Three studies with low risk of bias and ten with high risk of bias met the eligibility criteria. The supine resulted in the highest cardiac output compared to the 70 deg head-up tilt, sitting, and standing positions (very low- to moderate-quality evidences) and the lowest systemic vascular resistance compared to the 70 deg head-up tilt and standing positions (moderate-quality evidence). Additionally, the supine was associated with the highest total respiratory resistance compared to the 70 deg head-up tilt, left lateral, and standing positions (very low-to moderate-quality evidence) and higher alveolar ventilation than the prone (low-quality evidence).Conclusions The supine position has the most positive association with hemodynamic variables, resulting in the highest cardiac output and the lowest systemic vascular resistance. The upright positions (70 deg head-up tilt and standing positions) has the most positive association with the respiratory variables, resulting in the lowest total respiratory resistance.

Characterization of the IDENTIFYTM surface scanning system for radiation therapy setup on a closed-bore linac.

PURPOSE: In radiation therapy, surface guidance can be used for patient setup and intra-fraction motion monitoring. The surface guided radiation therapy (SGRT) system from Varian Medical systems, IDENTIFYTM, consists of three pods, including cameras and a random pattern projector, mounted on the ceiling. The information captured by the cameras is used to make a reconstruction of the surface. The aim of the study was to assess the technical performance of this SGRT system on a closed-bore linac. METHODS: Phantom measurements were performed to assess the accuracy, precision, reproducibility and temporal stability of the system, both in align and in load position. Translations of the phantoms in lateral, longitudinal, and vertical direction, and rotations around three axes (pitch, roll and yaw) were performed with an accurate, in-house built, positioning stage. Different phantom geometries and different surface colors were used, and various ambient light intensities were tested. RESULTS: The accuracy of the IDENTIFYTM system at the closed-bore linac was 0.07 mm and 0.07 degrees at load position, and 0.06 mm and 0.01 degrees at align position for the white head phantom. The precision was 0.02 mm and 0.02 degrees in load position, and 0.01 mm and 0.02 degrees in align position. The accuracy for the Penta-Guide phantom was comparable to the white head phantom, with 0.06 mm and 0.01 degrees in align position. The system was slightly less accurate for translations of the CIRS lung phantom in align position (0.20 mm, 0.05 degrees). Reproducibility measurements showed a variation of 0.02 mm in load position. Regarding the temporal stability, the maximum drift over 30 min was 0.33 mm and 0.02 degrees in load position. No effect of ambient light level on the accuracy of the IDENTIFYTM system was observed. Regarding different surface colors, the accuracy of the system for a black phantom was slightly worse compared to a white surface, but not clinical relevant. CONCLUSION: The IDENTIFYTM system can adequately be used for motion monitoring on a closed-bore linac with submillimeter accuracy. The results of the performed measurements meet the clinical requirements described in the guidelines of the AAPM and the ESTRO.

Successful treatment of 1 patient with chlorine-induced ARDS using awake self-prone positioning and nasal high-flow oxygen: A case report.

RATIONALE: Accidents involving chlorinated compounds in the context of cleaning are not uncommon. However, improving the treatment success rate for acute respiratory distress syndrome (ARDS) patients caused by chlorine gas presents significant challenges. PATIENT CONCERNS: A 28-year-old female was admitted to the intensive care unit after accidental inhalation of chlorine gas resulting in ARDS. DIAGNOSES: The patient was diagnosed with ARDS attributed to chlorine gas exposure. INTERVENTIONS: The intervention involved utilizing a combination of awake self-prone positioning (ASPP) and high-flow nasal oxygen therapy for treatment. OUTCOMES: After continuous ASPP and high-flow nasal oxygen therapy, the patient quickly recovered and was transferred out of the intensive care unit on the 6th day without any adverse events. LESSONS: ASPP combined with high-flow nasal oxygen therapy can improve patients' hypoxemia, prevent the need for intubation, avoid rapid deterioration of the condition, reduce treatment complexity, and lower mortality rate.

Patient Positioning Assistive Technology Applicable to the Existing Computed Tomography System: Estimation by Pixel Value of Scout Image.

ABSTRACT: This study aimed to propose a patient positioning assistive technique using computed tomography (CT) scout images. A total of 210 patients who underwent CT scans in a single center, including on the upper abdomen, were divided into a study set of 127 patients for regression and 83 patients for verification. Linear regression analysis was performed to determine the R2 coefficient and the linear equation related to the mean pixel value of the scout image and ideal table height (TH ideal ). The average pixel values of the scout image were substituted into the regression equation to estimate the TH ideal . To verify the accuracy of this method, the distance between the estimated table height (TH est ) and TH ideal was measured. The medians of age (in years), gender (male/female), height (in centimeters), and body weight (in kilograms) for the regression and verification groups were 68 versus 70, 85/42 versus 55/28, 163.8 versus 163.0, and 59.9 versus 61.9, respectively. Linear regression analysis indicated a high coefficient of determination ( R2 = 0.91) between the mean pixel value of the scout image and TH ideal . The correlation coefficient between TH ideal and TH est was 0.95 (95% confidence interval, 0.92-0.97; P < 0.0001), systematic bias was 0.2 mm, and the limits of agreement were -5.4 to 5.9 ( P = 0.78). The offset of the table height with TH est was 2.8 ± 2.1 mm. The proposed estimation method using scout images could improve the automatic optimization of table height in CT, and it can be used as a general-purpose automatic positioning technique.

Postoperative cognitive dysfunction after beach chair positioning compared to supine position in orthopaedic surgery in the elderly.

INTRODUCTION: Postoperative cognitive dysfunction (POCD) occurs in up to 26% of patients older than 60 years 1 week after non-cardiac surgery. Intraoperative beach chair positioning (BCP) is advantageous for some types of shoulder surgery. However, this kind of positioning leads to a downward bound redistribution of blood volume, with possible hypoperfusion of the brain. We hypothesized that patients > 60 years undergoing orthopaedic shoulder surgery in a BCP might experience more POCD than patients operated in the supine position (SP). MATERIAL AND METHODS: A single-centre, prospective observational trial of 114 orthopaedic patients was performed. Study groups were established according to the type of intraoperative positioning. Anaesthesiological management was carried out similarly in both groups, including types of anaesthetics and blood pressure levels. POCD was evaluated using the Trail Making Test, the Letter-Number Span and the Regensburger Word Fluency Test. The frequency of POCD 1 week after surgery was considered primary outcome. RESULTS: Baseline characteristics, including duration of surgery, were comparable in both groups. POCD after 1 week occurred in 10.5% of SP patients and in 21.1% of BCP patients (p = 0.123; hazard ratio 2.0 (CI 95% 0.794-5.038)). After 4 weeks, the incidence of POCD decreased (SP: 8.8% vs. BCP: 5.3%; p = 0.463). 12/18 patients with POCD showed changes in their Word Fluency Tests. Near-infrared spectroscopy (NIRS) values were not lower in patients with POCD compared to those without POCD (54% (50/61) vs. 57% (51/61); p = 0.671). CONCLUSION: POCD at 1 week after surgery tended to occur more often in patients operated in beach chair position compared to patients in supine position without being statistically significant.

Comparison of patient setup accuracy for optical surface-guided and X-ray-guided imaging with respect to the impact on intracranial stereotactic radiotherapy.

PURPOSE: The objective of this work is to estimate the patient positioning accuracy of a surface-guided radiation therapy (SGRT) system using an optical surface scanner compared to an X­ray-based imaging system (IGRT) with respect to their impact on intracranial stereotactic radiotherapy (SRT) and intracranial stereotactic radiosurgery (SRS). METHODS: Patient positioning data, both acquired with SGRT and IGRT systems at the same linacs, serve as a basis for determination of positioning accuracy. A total of 35 patients with two different open face masks (578 datasets) were positioned using X­ray stereoscopic imaging and the patient position inside the open face mask was recorded using SGRT. The measurement accuracy of the SGRT system (in a "standard" and an SRS mode with higher resolution) was evaluated using both IGRT and SGRT patient positioning datasets taking into account the measurement errors of the X­ray system. Based on these clinically measured datasets, the positioning accuracy was estimated using Monte Carlo (MC) simulations. The relevant evaluation criterion, as standard of practice in cranial SRT, was the 95th percentile. RESULTS: The interfractional measurement displacement vector of the SGRT system, σSGRT, in high resolution mode was estimated at 2.5 mm (68th percentile) and 5 mm (95th percentile). If the standard resolution was used, σSGRT increased by about 20%. The standard deviation of the axis-related σSGRT of the SGRT system ranged between 1.5 and 1.8 mm interfractionally and 0.5 and 1.0 mm intrafractionally. The magnitude of σSGRT is mainly due to the principle of patient surface scanning and not due to technical limitations or vendor-specific issues in software or hardware. Based on the resulting σSGRT, MC simulations served as a measure for the positioning accuracy for non-coplanar couch rotations. If an SGRT system is used as the only patient positioning device in non-coplanar fields, interfractional positioning errors of up to 6 mm and intrafractional errors of up to 5 mm cannot be ruled out. In contrast, MC simulations resulted in a positioning error of 1.6 mm (95th percentile) using the IGRT system. The cause of positioning errors in the SGRT system is mainly a change in the facial surface relative to a defined point in the brain. CONCLUSION: In order to achieve the necessary geometric accuracy in cranial stereotactic radiotherapy, use of an X­ray-based IGRT system, especially when treating with non-coplanar couch angles, is highly recommended.

Technical Trick: Traction Table-Assisted Lateral Decubitus Patient Positioning in Cephalomedullary Nailing of Geriatric Intertrochanteric Femur Fractures.

SUMMARY: Cephalomedullary nail fixation of geriatric intertrochanteric femur fractures is, and will continue to be, performed by most orthopaedic surgeons. The influence of technical factors on outcome is clear, and it is imperative that orthopaedic surgeons use contemporary strategies to achieve adequate reduction and fixation. The lateral patient position on a traction table potentially confers several advantages which surgeons can use to achieve quality outcomes even in patients who have challenging body morphology and/or fracture anatomy. A preferred surgical technique for lateral positioning is presented here and a case series comparing supine versus lateral nailing procedures. Lateral positioning was used more frequently in obese patients and by trauma-trained surgeons, and the results equal or exceed those in supine cases with respect to reduction and placement of fixation. Training surgeons in lateral nailing can deliver a reproducible strategy for reduction and fixation in straightforward and complex cases. By mastering the setup and technique on more simple cases, surgeons can be better prepared for the more complex where advantages of lateral nailing are even more apparent.

Effect of lying position on gastric residual volume in premature infants: A systematic review.

Premature infants' gastric residual volume may be affected by position. This systematic review was conducted to examine the effect of lying position on the gastric residual volume of preterm newborns fed by gastric tube. Electronic databases (PubMed, MEDLINE, MEDLINE Complete, Academic Search Ultimate, CINAHL Complete, Cochrane, and Scopus) were searched for randomized controlled experimental or quasiexperimental studies in English published between 2011 and 2022 investigating the effect of one or more lying positions on gastric residual volume in premature newborns. The PICOS strategy was used in preparing and reporting the systematic review. A total of 304 articles were retrieved, and the full texts of 12 articles were evaluated for suitability. After eliminating the excluded articles, 10 articles were included in the analysis. The quality of evidence varied, with four studies judged to have poor quality whereas the remaining six were considered to range from moderate to good in quality. Based on the results obtained from the studies, it was determined that gastric residual volume was the least in the right lateral and prone positions and more in the left lateral and supine positions compared with the other two positions, with no difference between the two latter positions. The methodological differences, such as the evaluation of different positions, the timing of positioning and the duration of maintaining in the same position, and the measurement times of gastric residual volume made it difficult to reach a definitive proof. We concluded that high-evidence studies evaluating all positions are needed.

Gel Rolls Increase Percutaneous Nephrolithotomy Radiation Exposure.

Introduction: Despite increasing interest in reducing radiation doses during endoscopic stone surgery, there is conflicting evidence as to whether percutaneous nephrolithotomy (PCNL) positioning (prone or supine) impacts radiation. We observed clinically that a patient placed prone on gel rolls had higher than expected radiation with intraoperative CT imaging and that gel rolls were visible on the coaxial imaging. We hypothesized that gel rolls directly increase radiation doses. Methods: Anthropomorphic experiments to simulate PCNL positions were performed using a robotic multiplanar fluoroscopy system (Artis Zeego Care+Clear, Siemens) and a 5-second coaxial imaging protocol (5s BODY). A fluoroscopy phantom was placed in various positions, including prone on a gel roll; prone on blankets of equal thickness; prone and supine directly on the table; and modified supine (MS) positions using a thin gel roll or rolled blanket. Impacts of C-arm direction and use of a 1 L saline bag were also evaluated. Measured dose area product (DAP) was compared for the groups. Results: Measured DAP was found to increase by 146 µGy*m2 (287%) when prone on gel rolls compared with only 62.29 (23%) when placed on blankets of equal thickness, although the model likely both overstates the relative impact and understates the absolute impact that would be seen clinically. Measured DAP between experimental groups also varied considerably despite fluoroscopy time being held constant. Conclusions: Our experiments support our hypothesis that gel rolls directly increase radiation dose, which has not been previously reported, using an anthropomorphic model. Surgeons should consider radiolucent materials for positioning to limit radiation exposure to patients and the surgical team.

Horizontal semicircular canal benign paroxysmal positional vertigo treated by acupuncture and moxibustion: A case report.

RATIONALE: Horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) is a second common canal of Benign Paroxysmal Positional Vertigo (BPPV); its actual incidence may have been underestimated because of its complex pathogenesis. Although the canalith repositioning maneuver is the treatment of choice, it has a high recurrence rate, affecting some patients' lives and psychology. We submit a case report describing acupuncture and wheat grain moxibustion treatment for HSC-BPPV. PATIENT CONCERNS: A 70-year-old patient with HSC-BPPV had low acceptability of the otolith repositioning treatment strategy and reported intolerance during the procedure. He turned to acupuncture as a result of recurrent attacks of vertigo. DIAGNOSES: Horizontal semicircular canal benign paroxysmal positional vertigo. INTERVENTIONS: The intervention project was acupuncture followed by wheat grain moxibustion treatment, administered once every 2 days, 3 times a week. The whole treatment period lasted for 2 months. OUTCOMES: The patient's clinical symptoms of vertigo improved significantly after 8 weeks of acupuncture and wheat grain moxibustion treatment. The Dizziness Handicap Inventory (DHI) and Visual Vertigo Analogue Scale (VVAS) scores decreased, thus verifying that the severity of vertigo was reduced. LESSONS: This brief clinical report suggests that acupuncture therapy may be a complementary option for treating HSC-BPPV.

A comparative analysis of the efficacy and safety of mini-percutaneous nephrolithotomy performed in the supine and prone positions for the treatment of pediatric kidney stones: a single-center experience.

Mini-percutaneous nephrolithotomy (MPCNL), which has a smaller tract size (14-20 Fr) than conventional percutaneous nephrolithotomy, has been shown to be safe and effective in pediatric patients with large and complex upper urinary tract stones. This study aimed to compare the efficacy and safety of MPCNL between the supine and prone positions in a pediatric population. The data of pediatric patients who underwent MPCNL at our center between January 2010 and March 2023 were retrospectively analyzed. According to the surgical position, the patients were divided into the prone (Group P) and supine (Group S) groups. In both groups, dilatation was performed using 14-18 Fr metallic dilators. The two groups were compared in terms of perioperative data, postoperative stone-free rates (SFRs), and complications. There were 36 (59%) patients in Group P and 25 (41%) patients in Group S. Stones were mostly located in the pelvis (49.2%) and second most frequently in the lower pole (27.9%). Fluoroscopy time was shorter in Group S but did not statistically significantly differ compared to Group P (p = 0.181). However, operation time was statistically significantly shorter in Group S (73.8 ± 35 vs. 99.8 ± 37.4 min, p = 0.008). Although there was no significant difference, relatively higher SFR were detected in Group S (88% vs. 83%, p = 0.725). Endoscopic combined intrarenal surgery (ECIRS) was performed on six (24%) patients in Group S, and the SFR was 100% among these patients. There was no significant difference between the two groups in terms of the presence of complications (16.7% vs. 16%, p = 0.945). Both supine and prone MPCNL appear to be safe and effective in the pediatric age group, with similar stone-free and complication rates. In the supine procedure, the operation time is shortened compared to the prone. In addition, simultaneous retrograde access has the potential to increase the overall success rate of surgery.

Setup accuracy and margins for surface-guided radiotherapy (SGRT) of head, thorax, abdomen, and pelvic target volumes.

The goal of the study was to evaluate the inter- and intrafractional patient setup accuracy of target volumes located in the head, thoracic, abdominal, and pelvic regions when using SGRT, by comparing it with that of laser alignment using patient skin marks, and to calculate the corresponding setup margins. A total of 2303 radiotherapy fractions of 183 patients were analyzed. All patients received daily kilovoltage cone-beam computed tomography scans (kV-CBCT) for online verification. From November 2019 until September 2020, patient setup was performed using laser alignment with patient skin marks, and since October 2020, using SGRT. The setup accuracy was measured by the six degrees of freedom (6DOF) corrections based on the kV-CBCT. The corresponding setup margins were calculated using the van Herk formula. Analysis of variance (ANOVA) was used to evaluate the impact of multiple factors on the setup accuracy. The inter-fractional patient setup accuracy was significantly better using SGRT compared to laser alignment with skin marks. The mean three-dimensional vector of the translational setup deviation of tumors located in the thorax, abdomen, and pelvis using SGRT was 3.6 mm (95% confidence interval (CI) 3.3 mm to 3.9 mm) and 4.5 mm using laser alignment with skin marks (95% CI 3.9 mm to 5.2 mm; p = 0.001). Calculation of setup margins for the combined inter- and intra-fractional setup error revealed similar setup margins using SGRT and kV-CBCT once a week compared to laser alignment with skin marks and kV-CBCT every other day. Furthermore, comparable setup margins were found for open-face thermoplastic masks with AlignRT compared to closed-face thermoplastic masks with laser alignment and mask marks. SGRT opens the possibility to reduce the number of CBCTs while maintaining sufficient setup accuracy. The advantage is a reduction of imaging dose and overall treatment time. Open-face thermoplastic masks may be used instead of closed-face thermoplastic masks to increase the patient's comfort.

[Study on the influence of Barbecure combined with Epley on residual dizziness of horizontal canal benign paroxysmal positional vertigo by SRM-vertigo diagnosis system].

Objective:To investigate the influence of Barbecure combined with Epley on residual dizziness of horizontal canal benign paroxysmal positional vertigo（HC-BPPV） by SRM-vertigo diagnosis system. Methods:A total of 406 patients diagnosed with HC-BPPV from Nov 2021 to Nov 2022 were enrolled by rapid axial roll test and Dix-Hallpike in the department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Xi'an Jiaotong University. The patients were divided into two groups by hospital card numbers, in which the numbers that were odd were considered as group A, and the numbers that were even were considered as group B. The group A underwent two circles of Barbecure repositioning procedure by SRM-vertigo diagnosis system, while the group B underwent two circles Barbecure combined with Epley repositioning procedure by SRM-vertigo diagnosis system. The treatment was stopped on the next day when two groups of patients were cured, and those who were not cured will continue treatment with the same method. Results:The cure rate of group A was 83.41%, and the cure rate of group B was 80.51%, the difference between the two groups was not-statistically significant difference（P>0.05）. The rate of residual dizziness of group A was 23.30%, the rate of residual dizziness of group B was 11.46%, the difference between the two groups was statistically significant（P<0.05）. Conclusion:The Barbecure combined with Epley otoliths repositioning maneuver by SRM-vertigo diagnosis system can significantly reduce the rate of residual dizziness after the treatment of HC-BPPV, and improve the quality of life of patients.

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. The evaluation involved monitoring translations for approximately 30 min and assessing the position detection accuracy for static and moving objects. Fifty clinical cases were used to evaluate the position detection accuracy and its relationship with the localization accuracy of CBCT before treatment. The detection accuracy of static and moving objects was within 1.0 mm using the phantom. However, the longitudinal direction tended to be larger than the other directions. Regarding the accuracy of localization in clinical cases, a strong and statistically significant (p < 0.01) correlation was observed in each direction. A detection accuracy within 1.0 mm is possible for static and moving objects. The detection accuracy of the patient setup using the InBore optical patient positioning system was extremely high, and the patient could be detected with high precision, suggesting its usefulness.

Relative thoracic changes from supine to upright patient position: A proton collaborative group study.

This study presents position changes of a few radiotherapy-relevant thoracic organs between upright and typical supine patient orientations. Using tools in a commercial treatment planning system (TPS), key anatomical distances were measured for four-dimensional CT data sets and analyzed for the two patient orientations. The uncertainty was calculated as the 95% confidence interval (CI) on the relative difference for each of the four analyzed changes for upright relative to supine, as follows: the distance of the bottom of the heart to the top of the sternum, it changed +2.6% or +4 mm (95% CI [+0.30%,+4.9%]); the distance of the center of the C3 vertebra to the backrest, it changed +29% (95% CI [+22%,+36%]); the contoured left and right lungs increased their volumes respectively: +17% (95% CI [+12%,+21%]) for the left, and +9.9% (95% CI [+4.1%,+16%]); and lastly, the distance from the top of the sternum to the top of the liver, but its uncertainty far exceeded the average change by a factor of two. This last result is therefore inconclusive, the others show that with 95% confidence that a change in internal positions is observed for lung volumes and heart position that could be important for upright treatments.

Evaluation and correlation of patient movement during online adaptive radiotherapy with CBCT and a surface imaging system.

PURPOSE: With the clinical implementation of kV-CBCT-based daily online-adaptive radiotherapy, the ability to monitor, quantify, and correct patient movement during adaptive sessions is paramount. With sessions lasting between 20-45 min, the ability to detect and correct for small movements without restarting the entire session is critical to the adaptive workflow and dosimetric outcome. The purpose of this study was to quantify and evaluate the correlation of observed patient movement with machine logs and a surface imaging (SI) system during adaptive radiation therapy. METHODS: Treatment machine logs and SGRT registration data log files for 1972 individual sessions were exported and analyzed. For each session, the calculated shifts from a pre-delivery position verification CBCT were extracted from the machine logs and compared to the SGRT registration data log files captured during motion monitoring. The SGRT calculated shifts were compared to the reported shifts of the machine logs for comparison for all patients and eight disease site categories. RESULTS: The average (±STD) net displacement of the SGRT shifts were 2.6 ± 3.4 mm, 2.6 ± 3.5 mm, and 3.0 ± 3.2 in the lateral, longitudinal, and vertical directions, respectively. For the treatment machine logs, the average net displacements in the lateral, longitudinal, and vertical directions were 2.7 ± 3.7 mm, 2.6 ± 3.7 mm, and 3.2 ± 3.6 mm. The average difference (Machine-SGRT) was -0.1 ± 1.8 mm, 0.2 ± 2.1 mm, and -0.5 ± 2.5 mm for the lateral, longitudinal, and vertical directions. On average, a movement of 5.8 ± 5.6 mm and 5.3 ± 4.9 mm was calculated prior to delivery for the CBCT and SGRT systems, respectively. The Pearson correlation coefficient between CBCT and SGRT shifts was r = 0.88. The mean and median difference between the treatment machine logs and SGRT log files was less than 1 mm for all sites. CONCLUSION: Surface imaging should be used to monitor and quantify patient movement during adaptive radiotherapy.

[SLEEP HABIT MODIFICATION AS A POSSIBLE PREVENTION OF RECURRENT BENIGN PAROXYSMAL POSITIONAL VERTIGO].

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is effectively treated with a variety of repositioning maneuvers but one-third to one-half of patients experience recurrence, usually within 2 years after the first attack. OBJECTIVES: The aim of this study was to investigate possible prevention of recurrent BPPV by sleep habit modification. METHODS: Patients diagnosed with posterior semicircular canal BPPV (p-BPPV) were asked their preferred lying side during nocturnal sleep. Following Epley maneuver they were recommended to change their head lying side at least every 2 hours during nocturnal sleep and to come back in case of recurrence. RESULTS: A total of 266 patients were diagnosed with p-BPPV. The mean patient's age was 57 years (range 14-87 years). There were 167 patients with right p-BPPV and 99 patients with left p-BPPV; 134 (50%) patients habitually slept on the right side. Of those, 112 (84%) were diagnosed with right p-BPPV (P= 0.0006); 87 patients (33%) habitually slept on the left side; 56 of them (64%) were diagnosed with left p-BPPV (P <0.0001). Among the 45 patients (17%) who expressed no preference concerning their sleeping positions, the right versus left p-BPPV was nearly even. During the follow-up period (1-80 months, mean 41) 11 patients (4%) were diagnosed with recurrent p-BPPV. Of those, 9 had a recurrence in the same posterior semicircular canal and 2 in the contralateral one. All of them reported that they had not modified their sleep habits. CONCLUSIONS: The results of our study can shed some light on the etiology of BPPV and may be helpful in preventing recurrent BPPV by changing sleep-position habits.

Large Variability of Head Angulation During the Epley Maneuver: Use of a Head-Mounted Guidance System with Visual Feedback to Improve Outcomes.

BACKGROUND: The aim of this study was to show the variability in head angulation during the canalolith repositioning maneuvers to treat benign paroxysmal positional vertigo and to describe a head-mounted benign paroxysmal positional vertigo guidance system to measure the head orientation. METHODS: A guidance system for benign paroxysmal positional vertigo was developed by NeuroEquilibrium Diagnostic Systems to measure head orientation and provide visual feedback and instructions to examiners during various maneuvers for benign paroxysmal positional vertigo. Twenty-five experienced examiners and 25 healthy volunteers (aged 21-35 years) were recruited. Each examiner applied the Epley maneuver twice in 1 volunteer: without and with the use visual feedback from a guidance system. Head orientation in both procedures was measured and compared. RESULTS: The trained examiners demonstrated a large variability in head orientation during the Epley maneuver, which was reduced by using the benign paroxysmal positional vertigo guidance system. There was a variability of 39-65° in head orientation measured without the guidance system. The use of the guidance system reduced the variation range to a sixfold decrease in variability. CONCLUSION: There is a large variability in head orientation when performing repositioning maneuvers, which could compromise the efficacy of benign paroxysmal positional vertigo treatment. Treatment for benign paroxysmal positional vertigo can be optimized by reducing this variability with a benign paroxysmal positional vertigo guidance system. It might also be a useful tool for teaching.