Setup Position Research Articles

Evaluation of the Treatment Field Deviations in Different Set-up Positions During Thoracic Radiotherapy in Lung Cancer Patients

Evaluation of the Treatment Field Deviations in Different Set-up Positions During Thoracic Radiotherapy in Lung Cancer Patients

CT-Based Collision Prediction Software for External-Beam Radiation Therapy.

PurposeBeam angle optimization is a critical issue for modern radiotherapy (RT) and is a challenging task, especially for large body sizes and noncoplanar designs. Noncoplanar RT techniques may have dosimetric advantages but increase the risk of mechanical collision. We propose a software solution to accurately predict colliding/noncolliding configurations for coplanar and noncoplanar beams.Materials and MethodsIndividualized software models for two different linear accelerators were built to simulate noncolliding gantry orientations for phantom/patient subjects. The sizes and shapes of the accelerators were delineated based on their manuals and on-site measurements. The external surfaces of the subjects were automatically contoured based on computed tomography (CT) simulations. An Alderson Radiation Therapy phantom was used to predict the accuracy of spatial collision prediction by the software. A gantry collision problem encountered by one patient during initial setup was also used to test the validity of the software. Results: In the comparison between the software estimates and on-site measurements, the noncoplanar collision angles were all predicted within a 5-degree difference in gantry position. The confusion matrix was calculated for each of the two empty accelerator models, and the accuracies were 98.7% and 97.3%. The true positive rates were 97.7% and 96.9%, while the true negative rates were 99.8% and 97.9%, respectively. For the phantom study, the collision angles were predicted within a 5-degree difference. The software successfully predicted the collision problem encountered by the breast cancer patient in the initial setup position and generated shifted coordinates that were validated to correspond to a noncolliding geometry.ConclusionThe developed software effectively and accurately predicted collisions for accelerator-only, phantom, and patient setups. This software may help prevent collisions and expand the range of spatially applicable beam angles.

In Silico Single-Fraction Stereotactic Ablative Radiation Therapy for the Treatment of Thoracic and Abdominal Oligometastatic Disease With Online Adaptive Magnetic Resonance Guidance

PurposeAlthough SABR can improve oncologic outcomes for patients with oligometastatic disease, treatment of metastases near critical organs remains challenging. The purpose of this study is to determine the dosimetric feasibility of delivering magnetic resonance imaging (MRI)-guided adaptive SABR in a single fraction for abdominal and thoracic metastases. Methods and MaterialsPreviously delivered MRI-guided radiation therapy plans for 20 patients with oligometastatic disease in the thorax or abdomen, with 70% (14/20) of the lesions within 8 mm from dose-limiting organs at risk (OARs), were used to simulate the delivery of 24 Gy in a single fraction. Planning objectives included planning target volume (PTV) V95% >90%, optimized PTV (PTVopt) V95% >90%, and PTVopt D99% >20 Gy with no OAR dose violations, where PTVopt removed overlap with nearby planning organ at risk volume (PRV). Single-fraction plans were simulated on the first 5 daily setup breath-hold MRI scans, and the plans were reoptimized to consider variations in setup position and anatomy. ResultsThe mean PTV V95% for single-fraction SABR plans was lower compared with multifraction plans (mean 85.4% vs 92.6%, P = .02), but mean PTVopt V95% was not different (95.3% vs 98.2%, P = .62). After reoptimization of the single-fraction plan to the treatment day MRI, there was an increase in mean PTV V95% (85.0% vs 88.1%, P = .05), increase in mean PTVopt V95% (92.7% vs 96.3%, P = .02), increase in mean PTVopt D99% (19.7 Gy vs 23.8 Gy, P < .01), increase in mean frequency of meeting PTV D99% >20 Gy (52% vs 87%, P < .01), and increase in mean gross tumor volume minimum dose (17.5 Gy vs 19.3 Gy, P < .01). Reoptimization decreased mean frequency of OAR dose constraint violation (48% vs 0%, P < .01). ConclusionsSingle-fraction MRI-guided SABR is a dosimetrically feasible treatment for oligometastases that allows for on-table adaptation to avoid OAR dose constraint violations, but this method requires clinical validation.

Influence of dynamic position, fluid intake, hydration, and energy expenditure on sustainable mobility transport

Energy is fundamental for any industrial development and globalization. Due to the demand of energy finding the cheap and environmental friendly commuting is vital. This study deals about how a saddle position affects the performance of the commuter. In regular and sprint cycling, the interaction between the bike and the rider is crucial. The performance of the cyclist depends on the bike setup and rider position. Besides, muscle force and aerodynamics also affect the biomechanical outputs. A series of tests were conducted on both hybrid and road bikes with a different test specimen. In the first session, the saddle height is kept at three different heights −10 mm, optimum and +10 mm and the performances value is noted. In the second session, the saddle was placed at three different angles (−8°, optimum and +8°) and the muscle force during pedalling is measured. Further, the position of saddle setback was done for three different configurations and the parameters such as force effectiveness and work effectiveness index were obtained. The real-time tests are done throughout the month with negligible traffic. The saddle height and saddle setback showed a significant difference in the performance of the bike. Further, the configuration of bike and its handlebar position also influences in the cyclist performance. Selecting the optimum saddle height using bike fitting technique can reduce the lower limb injury risk. Nevertheless, setting saddle at forward position and shifting little backward reduces the 10% of cumulative effort of the cyclist.

Towards Domain-independent Complex and Fine-grained Gesture Recognition with RFID

Gesture recognition plays a fundamental role in emerging Human-Computer Interaction (HCI) paradigms. Recent advances in wireless sensing show promise for device-free and pervasive gesture recognition. Among them, RFID has gained much attention given its low-cost, light-weight and pervasiveness, but pioneer studies on RFID sensing still suffer two major problems when it comes to gesture recognition. The first is they are only evaluated on simple whole-body activities, rather than complex and fine-grained hand gestures. The second is they can not effectively work without retraining in new domains, i.e. new users or environments. To tackle these problems, in this paper, we propose RFree-GR, a domain-independent RFID system for complex and fine-grained gesture recognition. First of all, we exploit signals from the multi-tag array to profile the sophisticated spatio-temporal changes of hand gestures. Then, we elaborate a Multimodal Convolutional Neural Network (MCNN) to aggregate information across signals and abstract complex spatio-temporal patterns. Furthermore, we introduce an adversarial model to our deep learning architecture to remove domain-specific information while retaining information relevant to gesture recognition. We extensively evaluate RFree-GR on 16 commonly used American Sign Language (ASL) words. The average accuracy for new users and environments (new setup and new position) are $89.03%$, $90.21%$ and $88.38%$, respectively, significantly outperforming existing RFID based solutions, which demonstrates the superior effectiveness and generalizability of RFree-GR.

Evaluation of automated pre-treatment and transit in-vivo dosimetry in radiotherapy using empirically determined parameters.

First reports on clinical use of commercially automated systems for Electronic Portal Imaging Device (EPID)-based dosimetry in radiotherapy showed the capability to detect important changes in patient setup, anatomy and external device position. For this study, results for more than 3000 patients, for both pre-treatment verification and in-vivo transit dosimetry were analyzed. For all Volumetric Modulated Arc Therapy (VMAT) plans, pre-treatment quality assurance (QA) with EPID images was performed. In-vivo dosimetry using transit EPID images was analyzed, including causes and actions for failed fractions for all patients receiving photon treatment (2018-2019). In total 3136 and 32,632 fractions were analyzed with pre-treatment and transit images respectively. Parameters for gamma analysis were empirically determined, balancing the rate between detection of clinically relevant problems and the number of false positive results. Pre-treatment and in-vivo results depended on machine type. Causes for failed in-vivo analysis included deviations in patient positioning (32%) and anatomy change (28%). In addition, errors in planning, imaging, treatment delivery, simulation, breath hold and with immobilization devices were detected. Actions for failed fractions were mostly to repeat the measurement while taking extra care in positioning (54%) and to intensify imaging procedures (14%). Four percent initiated plan adjustments, showing the potential of the system as a basis for adaptive planning. EPID-based pre-treatment and in-vivo transit dosimetry using a commercially available automated system efficiently revealed a wide variety of deviations and showed potential to serve as a basis for adaptive planning.

TO ASSESS THE DOSIMETRIC IMPACT ON PROSTATE, BLADDER AND RECTUM IN CARCINOMA PROSTATE DUE TO INTERFRACTIONALANATOMICAL VARIATION IN IMAGE GUIDED RADIATION THERAPY.

ABTRACT- Prostate cancer is second most frequent cancer in men and fifth leading cause of death worldwide. Most radiotherapy patients with prostate cancer are treated with intensity modulated radiotherapy. IMRT requires high spatial accuracy in localizing the target volume and high precision in treatment delivery, because even a small geographic miss can have a large dosimetric effect. However, the patient setup position and anatomy changes daily, particularly in the prostate region, due to rectum and bladder filling. Materials Methods: We analyzed 30 patients with prostate cancer patient treated with IMRT kV CBCT was performed for each patient twice per week during the entire course of treatment. The bladder, rectum, prostate and PTV were contoured on each CBCT scan. Results: Delivered dose of prostate D95% and prostate D100% was 99.15% and 93.66% respectively and mean value of V70 for bladder was 16% and delivered value was 16.45%. Whereas the mean value of V70 of plan for rectum was 18.12% and delivered value was 27.58%. Conclusion: Interfractional variation during prostate radiotherapy can results in substantial difference between planned and delivered doses, particularly in critical structure. IG-IMRT is useful tool in assessing dosimetric changes in critical structure due to interfractional anatomical interfractional anatomical variation in prostate radiotherapy.

Analyzing the Positional uncertainties in 3dcrt ca breast Patients with Free Breathing and Active Breath Coordinator Gating Immobilization Devices

Aim: The aim of this study is to rule out the difference in positional setup errors when using immobilization device such as thermoplastic mould for free breathing and vacloc with ABC gating in ca breast patient treating with 3DCRT technique. Objective: The study is to compare the patient setup uncertainties using two different immobilization device, one with standard thermoplastic mould and other with vacuum cushion with active breath control gating in our clinical setup. Methodology: fourteen patients with ca breast are taken for the study. seven patients are undergone immobilization using standard thermoplastic moulding and remaining seven patients undergone, vacuum cushion with active breath control DIBH (deep inspiration breath hold) gating. CT was taken and 3dcrt plan were done according to the standard protocol. Prior to the treatment CBCT was taken, matching was done in XVI with the reference images, to rule out any positional shifts. Positional Shifts on all 3 axes such x, y, z is noted with rotational shift. Comparison were done on systematic error (?), random error (?), mean displacement vector (R), mean setup error (M). Result: immobilization device used by vacloc with DIBH ABC gating shows very less shifts in all direction, especially longitudinal direction compared with mould one, which we are using routinely in our department.

Validating the clinical use of Breathe Well, a novel breathe monitoring device.

Respiratory motion management has become increasingly important in the accurate delivery of radiotherapy. Recently, a novel device, Breathe Well, has been developed, which provides motion management by tracking the movement of external surrogates. This paper has comprehensively assessed the measurement accuracy of Breathe Well in various clinical conditions. The results suggest that the Breathe Well device has good reproducibility, although it demonstrates larger measurement errors in certain setup positions. However, this measurement error becomes trivial if it is setup consistently over the entire course of treatment. For other setup positions, the Breathe Well device can reach a ± 1.0mm spatial accuracy when the motion amplitude is less than or equal to 20mm, similar to that of the Varian RPM system. The phase measurement from Breathe Well agrees well with that of the RPM and the QUASAR phantom, indicating that the device has potentials for phase-related clinical applications such as gating.

A method to deal with correlations affecting γ counting efficiencies in analytical chemistry measurements performed by k0-NAA

The ratio of γ counting efficiencies is very important in trace element analysis carried out by prompt- and delayed-γ neutron activation based on k0 standardization. Although the effect of correlation between counting efficiencies is well known and methods have been developed and adopted in prompt-γ neutron activation analysis to correctly evaluate the uncertainty, proposals and applications in delayed-γ neutron activation analysis are still lacking. To fill the gap, we developed a new method based on the use of reference γ-sources to determine the detection efficiency ratio and its uncertainty by taking full account of correlations. A measurement model that differs to some extent from the classical k0 formulation widely used in delayed-γ neutron activation analysis is required. A detection system was characterized to test the suitability of the method in a double-counting position setup, where the standard is placed far from the detector end-cap and the sample is placed close to it. The present paper is a significant expansion of a relevant abstract presented at the ‘Mathematical and Statistical Methods for Metrology’ Workshop, Torino, Italy, 30–31 May 2019 (pp 27–28 in www.msmm2019.polito.it/programme).

Different Lower-Limb Setup Positions Do Not Consistently Change Backstroke Start Time to 10 m.

Backstroke starts involve the athlete starting from a flexed position with their feet against the pool wall and then extending their ankles, knees, hips and back to push off; however, swimmers can start in different positions. The purpose of this study was to evaluate the performance impact of different knee extension angles in the setup position for a backstroke start. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees maximally flexed, and one with the knees less flexed. The start handles and touchpad were instrumented with multi-axial force sensors. Activity of major hip and knee extensors was measured using surface electromyography. Body position in the sagittal plane was recorded using high-speed cameras. There was no overall difference in time to 10 m between the two conditions (p = 0.36, dz = 0.12), but some participants showed differences as large as 0.12 s in time to 10 m between start conditions. We observed that starts performed from a setup position with less knee flexion had an average 0.07 m greater head entry distance (p = 0.07, dz = 0.53), while starts from a setup position with maximal knee flexion had an average 0.2 m/s greater takeoff velocity (p = 0.02, dz = 0.78). Both head entry distance and takeoff velocity are related to start performance, suggesting each position may optimize different aspects of the backstroke start. Coaches should assess athletes individually to determine which position is optimal.

Design and Investigate of Flushing System for Electrical Discharge Machining (EDM) Application

Electrical Discharge Machining (EDM) is high precision machining process in which no actual contact between the workpiece and electrode during sparking. Dielectric fluid play a role as flushing medium and semiconductor between workpiece and electrode to stabilization and controlled spark gap ionization condition. In real condition, nozzle flushing system in EDM machine not able to complete remove debris formed during machining and affect the machining performance. Improper flushing due to lack of guideline at setup position of nozzle and inlet pressure caused low material removal rate, irregular tool and higher cost on raw material. To overcome this problem, the design and investigate of flushing system in EDM application is required. The design and investigation undergo by simulation of ANSYS Computational Fluid Dynamics (CFD) with a virtual experiment to accurate prediction of flushing performance. The influence of nozzle size and inlet pressure supplied on flushing efficiency were analyzed to avoid improper flushing on die-sinking EDM process. The simulation and experiments clarified that the higher inlet pressure, P=0.20 bar and larger nozzle diameter, D=6mm resulting in higher total pressure which is 2647.16 Pa. Furthermore, the streamline of velocity and eddy viscosity contour in the work tank using to analyze the turbulence zone by nozzle flushing obtained by the CFD analysis. The condition in case 5 (D=5mm, P=0.15 bar) is more efficiency on debris removal rate based on the result of high total pressure on machining zone and eddy viscosity contour showed the turbulence zone only formed area near to outlet of system. The model results have been shown good agreement with experiment and co-relation data.

Evaluation of the effect of random setup errors on dose delivery in Intensity Modulated Radiotherapy

Abstract Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Intensity Modulated Radiotherapy plans using Octavius 4D phantom. Materials and methods: 11 patients with cancer of H&amp;N were selected for this study. An IMRT plan was created for each patient. The IMRT quality assurance plans were transferred to Mosaiq workstation in a linear accelerator. These plans were delivered at the reference treatment position. Subsequently, the QA plans were delivered on the Octavius 4D phantom after introducing errors in various translational and rotational directions. The setup inaccuracies introduced varied from 1 mm to 5 mm along X, Y. These setup uncertainties were then introduced along X and Y direction simultaneously in equal measures. Similarly, IMRT plans were delivered also after introducing roll and yaw rotation of 1, 2 and 3 degrees in phantom. The deviation of gamma indices at all these positions was analyzed with respect to the reference setup position. Results: The percentage of points passing the gamma acceptance criterion decrease as we increase the setup error. The change is found to be very insignificant with setup error up to 2 mm along X, Y or XY direction. Similarly, the rotational error of up to 3 degrees is found to be acceptable. Conclusions: Small setup (&lt; 2 mm) correction in patients may not adversely affect the dose delivery. But an error of similar magnitude in 2 directions simultaneously has a much greater impact on IMRT dose delivery.

Application of Two-Dimensional Detector Arrays to the Delivery Quality Assurance in Breast IMRT

Most two-dimensional (2D) detector arrays used for the verification of the intensity-modulated radiotherapy (IMRT) dose distribution comprise diode detectors or ion chamber detectors. These detectors show different sensitivities depending on the angle of incidence of the IMRT beam on the detector. In this study, the effect of the radiation beam’s angle of incidence onto the detector was analyzed in order to find an optimal 2D detector array setup position for delivery quality assurance in breast IMRT. For breast IMRT plans, comprising mostly tangential fields, the dose distribution produced with true composite beams was measured by arranging 2D detector array devices at various angles. The change in dosimetric accuracy was then assessed as a function of the radiation beam’s angle of incidence. A total of 72 dose distributions were measured and analyzed for 12 breast IMRT plans. Both the diode detector array and the ion chamber array showed a higher gamma passing ratio in the sagittal dose distribution measurement, where the beam’s angle of incidence was relatively larger. This study indicates that using a 2D detector array placed at a relatively large angle of incidence offers a more accurate verification of the IMRT dose distribution.

A comparison of dose and set-up accuracy between flexed and extended neck positions in Helical Tomotherapy of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) patients treated with Helical Tomotherapy (HT) are commonly set up in an extended neck (EN) or a flexed neck (FN) position. This study investigated the dosimetric and set-up accuracy differences between these 2 set-up positions. Twenty NPC patients treated with HT from each set-up position were retrospectively recruited. HT plans were computed using the same target prescription and organs at risks (OARs) constraints for both set-up positions. The doses parameters of the target volumes and OARs were assessed. Daily megavoltage CT images were retrieved to obtain the set-up errors at 4th (C4) and 7th (C7) cervical levels. The mean values of these parameters were compared between the 2 set-up positions. The dose to NP target in FN group was more conformal than EN group, while the conformity of the neck targets in FN group were significantly lower. For the OARs, the temporal lobe, cerebellum, and hippocampus in FN group received significantly lower doses than the EN. However, the optic structures, brain stem, spinal cord, and parotid glands received higher doses in FN group. The systematic errors at C4 and C7 levels in FN group were larger in all translational directions except the ML direction at C7 level. With regard to radiotherapy of NPC patient using helical tomotherapy, FN position reduced doses to intracranial structures but increased doses to optic structures and other structures when compared with the EN position. In terms of set-up accuracy at the neck region, EN position was relatively better.

69 Analysis and evaluation of a fixed vertical couch position technique in comparison with a placement based on tattoo and Couch Move Assistant on linacs Elekta Synergy S

Introduction. In our department the daily patient setup is based on tattoos and the offsets, eventually registered in the Record and Verify software MOSAIQ (version 2.6), are then applied with the Couch Move Assistant (CMA). The procedure is: for the four first days of the treatment, a Cone Beam Computed Tomography (CBCT) is taken and the correction is applied even for a displacement of 1 mm. After the four fractions, the mean of a systematic error (SE), if detected, will be calculated and applied for the following fractions. For the prostate treatment if the means is greater than 4.5 mm, the mean of the offsets will be added automatically through MOSAIQ for the rest of the next fractions. When there is prostate marker (gold seeds), a CBCT is taken daily and no SE correction is applied. Based on the publication of Petillion [1] Petillion, S. et al. Efficacy and workload analysis of a fixed vertical couch position technique and a fixed-action–level protocol in whole-breast radiotherapy. J Appl Clin Med Phys 16, 279–290 (2015). Google Scholar et al. in 2015 for the whole breast radiotherapy, a fixed vertical couch position (FVCP) setup is expected to be more precise than a setup based on skin marks: because of skin mobility, imprecision of tattooing during simulation, precision of the CMA module. For a fixed couch vertical positioning, the setup would be as followed: patient setup in left-right (LR) and superior-inferior (SI) based on the skin marks. For the anterior-posterior (AP) setup, it would be based on table height measured in the Treatment Planning System (TPS). The aim of this study is to apply the same methodology for prostate treatment.

A novel approach to Verify air gap and SSD for proton radiotherapy using surface imaging

PurposeTo develop a novel approach to accurately verify patient set up in proton radiotherapy, especially for the verification of the nozzle – body surface air gap and source-to-skin distance (SSD), the consistency and accuracy of which is extremely important in proton treatment.MethodsPatient body surfaces can be captured and monitored with the optical surface imaging system during radiation treatment for improved intrafraction accuracy. An in-house software package was developed to reconstruct the patient body surface in the treatment position from the optical surface imaging reference capture and to calculate the corresponding nozzle – body surface air gap and SSD. To validate this method, a mannequin was scanned on a CT simulator and proton plans were generated for a Mevion S250 Proton machine with 20 gantry/couch angle combinations, as well as two different snout sizes, in the Varian Eclipse Treatment Planning Systems (TPS). The surface generated in the TPS from the CT scan was imported into the optical imaging system as an RT Structure for the purpose of validating and establishing a benchmark for ground truth comparison. The optical imaging surface reference capture was acquired at the treatment setup position after orthogonal kV imaging to confirm the positioning. The air gaps and SSDs calculated with the developed method from the surface captured at the treatment setup position (VRT surface) and the CT based surface imported from the TPS were compared to those calculated in TPS. The same approach was also applied to 14 clinical treatment fields for 10 patients to further validate the methodology.ResultsThe air gaps and SSDs calculated from our program agreed well with the corresponding values derived from the TPS. For the phantom results, using the CT surface, the absolute differences in the air gap were 0.45 mm ± 0.33 mm for the small snout, and 0.51 mm ± 0.49 mm for the large snout, and the absolute differences in SSD were 0.68 mm ± 0.42 mm regardless of snout size. Using the VRT surface, the absolute differences in air gap were 1.17 mm ± 1.17 mm and 2.1 mm ± 3.09 mm for the small and large snouts, respectively, and the absolute differences in SSD were 0.81 mm ± 0.45 mm. Similarly, for patient data, using the CT surface, the absolute differences in air gap were 0.42 mm ± 0.49 mm, and the absolute differences in SSD were 1.92 mm ± 1.4 mm. Using the VRT surface, the absolute differences in the air gap were 2.35 mm ± 2.3 mm, and the absolute differences in SSD were 2.7 mm ± 2.17 mm.ConclusionThese results showed the feasibility and robustness of using an optical surface imaging approach to conveniently determine the air gap and SSD in proton treatment, providing an accurate and efficient way to confirm the target depth at treatment.

Assessment of the use of different imaging and delivery techniques for cranial treatments on the Halcyon linac

PurposeIn this work, we investigated the effect on the workflow and setup accuracy of using surface guided radiation therapy (SGRT) for patient setup, megavoltage cone beam CT (MVCBCT) or kilovoltage cone beam CT (kVCBCT) for imaging and fixed IMRT or volumetric‐modulated arc therapy (VMAT) for treatment delivery with the Halcyon linac.MethodsWe performed a retrospective investigation of 272 treatment fractions, using three different workflows. The first and second workflows used MVCBCT and fixed IMRT for imaging and treatment delivery, and the second one also used SGRT for patient setup. The third workflow used SGRT for setup, kVCBCT for imaging and VMAT for delivery. Workflows were evaluated by comparing the number of fractions requiring repeated imaging acquisitions and the time required for setup, imaging and treatment delivery. Setup position accuracy was assessed by comparing the daily kV‐ or MV‐ CBCT with the planning CT and measuring the residual rotational errors for pitch, yaw and roll angles.ResultsWithout the use of SGRT, the imaging fields were delivered more than once on 11.1% of the fractions, while re‐imaging was necessary in 5.5% of the fractions using SGRT. The total treatment time, including setup, imaging, and delivery, for the three workflows was 531 ± 157 s, 503 ± 130 s and 457 ± 91 s, respectively. A statistically significant difference was observed when comparing the third workflow with the first two. The total residual rotational errors were 1.96 ± 1.29°, 1.28 ± 0.67° and 1.22 ± 0.76° and statistically significant differences were observed when comparing workflows with and without SGRT.ConclusionsThe use of SGRT allowed for a reduction of re‐imaging during patient setup and improved patient position accuracy by reducing residual rotational errors. A reduction in treatment time using kVCBCT with SGRT was observed. The most efficient workflow was the one including kVCBCT and SGRT for setup and VMAT for delivery.

A randomised observational study of individualised variations in the start position of the closed-kinetic chain upper extremity stability test

ObjectivesTo assess the reliability, precision and differences between scores produced using the standard 36″ start position and 3 modified start positions of the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), towards normalisation to the individual. DesignRCT of 4 conditions. SettingClinical. ParticipantsThirty-four asymptomatic individuals. Main outcome measuresUsing an RCT method, variations in CKCUEST starting hand position were tested using hand spacing at standard 36″, 50% height, bi-acromial distance, and bi-acromial distance with reach to 36″. The average number of touches over 3 × 15 s maximal efforts were used to assess the intra-variation reliability, minimum detectable change (MDC) and differences to the standard 36″ start position. ResultsThe most reliable variation was the 50% height (ICC: 0.93) and with the smallest MDC (14%). 36″ results were second-most reliable (ICC: 0.90), with a low MDC (19%). Significant differences were found between bi-acromial and 50% height to the 36″ standard setup. ConclusionsA setup position where the hand separation is 50% of the individual’s height offers excellent repeated measures reliability and the smallest MDC, suggesting it is the most sensitive to change and is a recommendation to clinicians. Conversion calculations between start variations are presented.

Accuracy and reliability of the expected root position setup on clinical decision making of root position at midtreatment

Accurate root position is imperative for successful orthodontic treatment that is stable and functional. Current methods to monitor root position are either inaccurate or use relatively high levels of radiation. A method to generate an expected root position (ERP) setup has been reported to have the potential to accurately evaluate root position with minimal radiation. The purpose of this study was to determine the accuracy and reliability of the clinical decisions made on root position using the ERP setup. This retrospective study included 10 subjects who had pretreatment and midtreatment cone-beam computed tomography (CBCT) scans and study models. An ERP setup was generated for all patients at midtreatment. Four examiners assessed both the CBCT scan and ERP setup and made clinical decisions regarding the root position with each method. Cohen's kappa was determined to assess intraoperator and intermethod reliability. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the accuracy of the ERP setup. The kappa values for intraoperator reliability for both the CBCT scan and ERP setup fell within the 0.61-0.80 range. The kappa values for intermethod reliability between the CBCT scan and ERP setup fell within the 0.61-0.80 range for all tooth groups. The sensitivity of the ERP setup ranged from 0.72 to 0.90, specificity ranged from 0.89 to 0.97, positive predictive value ranged from 0.57 to 0.85, and negative predictive value ranged from 0.93 to 0.99. This study demonstrated that the ERP setup, when compared with the gold standard CBCT scan, was accurate and reliable in making clinical decisions regarding root position at midtreatment.