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Purpose: In the last few years, there has been a growing interest in surface imaging for patient positioning in external radiation therapy. The aim of this study is to evaluate the accuracy of daily patient positioning using the Azure Kinect surface imaging., Methods: A total of 50 fractions in 10 patients including lung, pelvic, and head and neck tumors were analyzed in real time. A rigid registration algorithm, based on the iterative closest point (ICP) approach, is employed to estimate the patient position in 6 degrees of freedom (DOF). This position is compared to the reference values obtained by the radiograph imaging. The mean setup error and its standard deviation were calculated for all measured fractions., Results: The positioning error showed 1.1 ± 1.1 mm in lateral, 1.8 ± 2.1 mm in longitudinal, and 0.8 ± 1.1 mm in vertical, and 0.3°± 0.4° in yaw, 0.2°± 0.2° in pitch, and 0.2°± 0.2° in roll directions. The larger setup error occurred in pelvic regions., Conclusion: We have evaluated in a radiotherapy set-up considering different patient anatomical locations, a depth measurement based surface imaging solution for patient positioning considering the 6 DOF couch motion. We showed that the proposed solution allows an accurate patient positioning without the need for patient markings or the use of additional radiation dose., (© 2021 American Association of Physicists in Medicine.)

Objective: To the knowledge of the authors, no data about the reproducibility and accuracy of 3-dimensional surface imaging of the face using a whole-body scanner are available. Thus, the objective of this investigation was to assess the reproducibility of facial scans acquired using a whole-body imaging device., Material and Methods: This investigation investigated 220 3-D scans of a total of 22 healthy volunteers (with a mean age of 29.36 years). Two consecutive 3-D images using a Vectra WB360 of the volunteers were obtained utilizing a whole-body imaging device. Predefined distances in the face were performed in each scan and compared. Furthermore, surface deviation between two consecutively captured scans was assessed., Results: The distance with the smallest statistical significance was found to be at the nose with p = 0.998, while the biggest statistical significance was found in the midface with p = 0.658. The area with the biggest surface deviation between the superimposed scans was the neck with a root mean square (RMS) of 1.62 ± 1.71, and the area with the smallest surface deviation was the forehead with a RMS of 0.17 ± 0.05., Conclusion: The whole-body imaging device investigated in this study can be utilized to capture the face and provides enough accuracy to compare scans. Even though not directly investigated, it can be hypothesized that the error caused by repositioning the patient between a baseline and a follow-up scan will not be too big to consider measurements performed with the whole-body imaging device as impractical., (© 2021 The Authors. Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

BackgroundThree-dimensional (3D) scanning is an established method of breast volume estimation. However, this method can never be entirely precise, since the thoracic wall cannot be imaged by the surface scanner. Current methods rely on interpolation of the posterior breast border from the surrounding thoracic wall. Here, we present a novel method to calculate the posterior border and increase the accuracy of the measurement.MethodsUsing principal component analysis, computed tomography images were used to build a statistical shape model (SSM) of the thoracic wall. The model was fitted to 3D images and the missing thoracic wall curvature interpolated (indirect volumetry). The calculations were evaluated by ordinary least squares regression between the preoperative and postoperative volume differences and the resection weights in breast reduction surgery (N = 36). Also, an SSM of the breast was developed, allowing direct volumetry. Magnetic-resonance images (MRI) and 3D scans were acquired from 5 patients in order to validate the direct 3D volumetry.ResultsVolumetry based on a SSM exhibited a higher determination coefficient (R2 = 0,737) than the interpolation method (R2 = 0,404). The methods were not equivalent (p = 0.75), suggesting that the methods significantly differ. There was no influence of BMI on the correlation in either method. The MRI volumetry had a strong correlation with the 3D volumetry (R2 = 0,978).ConclusionThe SSM-based method of posterior breast border calculation is reliable and superior to the currently used method of interpolation. It should serve as a basis of software applications aiming at calculation of breast volume from 3D surface scanning data.

A new approach -- the digital holographic surface imaging (DHSI) -- is proposed for in situ observation of the electrode surface during a typical localized corrosion process. The test results show that the experimental system is sensitive in detecting ions' concentration changes in the vicinity of the electrode surface. The phase maps obtained with this method capture the dynamic concentration changes in front of the steel surface and exhibit the initiation, propagation or re-passivation processes of metastable pits. The proposed method can provide visual evidence of localized dissolution on the electrode surface and offer an in situ and simple means to monitor early-stage corrosion in real time, thereby exhibiting potential for extensive use in the study of electrochemical dynamic processes. [ABSTRACT FROM AUTHOR]

Importance: Finding a suitable fit in glasses for pediatric patients with congenital and acquired craniofacial abnormalities is difficult; consequently, these children are at high risk of vision loss secondary to refractive amblyopia as they often have poor adherence to daily glasses wearing. Custom 3-dimensional (3D)-printed glasses may have an improved design and fit, but access is limited by the availability of computed tomography and magnetic resonance imaging (MRI)., Objective: To describe a method for using a commercially available smartphone 3D surface imaging (3DSI) technique to capture facial anatomy as a basis for custom glasses design., Design, Setting, and Participants: This quality improvement study analyzes data from a case series in a primary academic center with multiple referral centers throughout the United States. The evaluation included reported fit descriptions from patients with poor glasses adherence due to craniofacial abnormalities., Main Outcomes and Measures: Key anatomic parameters for glasses fit (face width, distance from ear bridge to nasal bridge, distance from center of pupil to center of nasal bridge, distance from lateral to medial canthus, ear vertical offset, and nasal bridge width) were compared between scans. A 3DSI scan was considered successful if these key parameters could be determined and the difference in measurements was less than 5% between MRI and 3DSI. A second outcome measure included the fit of glasses designed by the 3DSI method as reported by the patient, parent, or guardian., Results: Measurements of key parameters for glasses fit were similar across MRI and 3DSI scans with a mean (SD) difference of 1.47 (0.79) mm between parameters (range, 0.3-4.60 mm). Among 20 patients aged 1 to 17 years with craniofacial abnormalities, all achieved a successful fit (reporting daily glasses adherence without irritation) as judged by the patient, parent, or guardian. A mean of 1.7 revisions were made from initial prototype to final frame production using 3DSI technology., Conclusions and Relevance: This study demonstrated that smartphone-enabled 3DSI coupled with widely available 3D printing technology can produce custom frames with a successful fit for patients with craniofacial anomalies. This accessible and well-tolerated imaging process may have implications for adherence with glasses wearing among patients at risk of vision loss due to amblyopia.

Background: To quantify the surgical outcomes of transconjunctival fat repositioning technique, we study the lower periorbital area with magnetic resonance imaging (MRI) and three-dimensional (3D) surface imaging. Methods: The preoperative and postoperative images were analyzed. The T1-weighted MR images in the quasi-sagittal plane parallel to the long axis of the orbit and passing through the globe center were used to measure the transposed fat, and 3D comparison was performed to calculate the tear trough depth. Changes throughout the surgery and their relationships with clinical characteristics were statistically analyzed. Results: A total of 11 patients who underwent surgery were included. The mean follow-up period was 10.1 months. MRI measurements showed that the fat area beneath the tear trough increased from 0 to 22.7 ± 6.7 mm 2 after fat repositioning, whereas the fat area of the eyelid bag decreased from 46.3 ± 11.0 mm 2 to 25.5 ± 14.0 mm 2 . The 3D results revealed an increase in thickness by 1.2 ± 0.4 mm in the tear tough areas. Conclusion: Both MRI and 3D imaging provide options to objectively assess the fat-repositioning technique.

Purpose: To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs., Methods: Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (R a ) and root-mean-squared roughness (R q ) values were obtained and compared statistically., Results: In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured R a and R q values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05)., Conclusion: Various different topographical traits were observed in three diffractive multifocal IOLs. The R a values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface R a values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces., Competing Interests: The authors declare that they have no conflict of interest./Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Background Accurate breast volume assessment is a prerequisite to preoperative planning, as well as intraoperative decision making in breast reconstruction surgery. The use of three-dimensional surface imaging (3D scanning) to assess breast volume has many advantages. However, before employing 3D scanning in the field, the tool's validity should be demonstrated. The purpose of this study was to confirm the validity of 3D-scanning technology for evaluating breast volume. Methods We reviewed the charts of 25 patients who underwent breast reconstruction surgery immediately after total mastectomy. Breast volumes using the Axis Three 3D scanner, water-displacement technique, and magnetic resonance imaging (MRI) were obtained bilaterally in the preoperative period. During the operation, the tissue removed during total mastectomy was weighed and the specimen volume was calculated from the weight. Then, we compared the volume obtained from 3D scanning with those obtained using the water-displacement technique, MRI, and the calculated volume of the tissue removed. Results The intraclass correlation coefficient (ICC) of breast volumes obtained from 3D scanning, as compared to the volumes obtained using the water-displacement technique and specimen weight, demonstrated excellent reliability. The ICC of breast volumes obtained using 3D scanning, as compared to those obtained by MRI, demonstrated substantial reliability. Passing-Bablok regression showed agreement between 3D scanning and the water-displacement technique, and showed a linear association of 3D scanning with MRI and specimen volume, respectively. Conclusions When compared with the classical water-displacement technique and MRI-based volumetry, 3D scanning showed significant reliability and a linear association with the other two methods.

Timely monitoring nitrogen status of rice crops with remote sensing can help us optimize nitrogen fertilizer management and reduce environmental pollution. Recently, the use of near-surface imaging spectroscopy is emerging as a promising technology that can collect hyperspectral images with spatial resolutions ranging from millimeters to decimeters. The spatial resolution is crucial for the efficiency in the image sampling across rice plants and the separation of leaf signals from the background. However, the optimal spatial resolution of such images for monitoring the leaf nitrogen concentration (LNC) in rice crops remains unclear. To assess the impact of spatial resolution on the estimation of rice LNC, we collected ground-based hyperspectral images throughout the entire growing season over 2 consecutive years and generated ten sets of images with spatial resolutions ranging from 1.3 to 450 mm. These images were used to determine the sensitivity of LNC prediction to spatial resolution with three groups of vegetation indices (VIs) and two multivariate methods Gaussian Process regression (GPR) and Partial least squares regression (PLSR). The reflectance spectra of sunlit-, shaded-, and all-leaf leaf pixels separated from background pixels at each spatial resolution were used to predict LNC with VIs, GPR and PLSR, respectively. The results demonstrated all-leaf pixels generally exhibited more stable performance than sunlit- and shaded-leaf pixels regardless of estimation approaches. The predictions of LNC required stage-specific LNC~VI models for each vegetative stage but could be performed with a single model for all the reproductive stages. Specifically, most VIs achieved stable performances from all the resolutions finer than 14 mm for the early tillering stage but from all the resolutions finer than 56 mm for the other stages. In contrast, the global models for the prediction of LNC across the entire growing season were successfully established with the approaches of GPR or PLSR. In particular, GPR generally exhibited the best prediction of LNC with the optimal spatial resolution being found at 28 mm. These findings represent significant advances in the application of ground-based imaging spectroscopy as a promising approach to crop monitoring and understanding the effects of spatial resolution on the estimation of rice LNC.

Dynamic three-dimensional (3D) surface imaging by phase-shifting fringe projection profilometry has been widely implemented in diverse applications. However, existing techniques fall short in simultaneously providing the robustness in solving spatially isolated 3D objects, the tolerance of large variation in surface reflectance, and the flexibility of tunable working distances with meter-square-level fields of view (FOVs) at video rate. In this work, we overcome these limitations by developing multi-scale band-limited illumination profilometry (MS-BLIP). Supported by the synergy of dual-level intensity projection, multi-frequency fringe projection, and an iterative method for distortion compensation, MS-BLIP can accurately discern spatially separated 3D objects with highly varying reflectance. MS-BLIP is demonstrated by dynamic 3D imaging of a translating engineered box and a rotating vase. With an FOV of up to 1.7 m × 1.1 m and a working distance of up to 2.8 m, MS-BLIP is applied to capturing full human-body movements at video rate.

Purpose: Monitoring of physiological parameters is a major concern in Intensive Care Units (ICU) given their role in the assessment of vital organ function. Within this context, one issue is the lack of efficient noncontact techniques for respiratory monitoring. In this paper, we present a novel noncontact solution for real-time respiratory monitoring and function assessment of ICU patients., Methods: The proposed system uses a Time-of-Flight depth sensor to analyze the patient's chest wall morphological changes in order to estimate multiple respiratory function parameters. The automatic detection of the patient's torso is also proposed using a deep neural network model trained on the COCO dataset. The evaluation of the proposed system was performed on a mannequin and on 16 mechanically ventilated patients (a total of 216 recordings) admitted in the ICU of the Brest University Hospital., Results: The estimation of respiratory parameters (respiratory rate and tidal volume) showed high correlation with the reference method (r = 0.99; P < 0.001 and r = 0.99; P < 0.001) in the mannequin recordings and (r = 0.95, P < 0.001 and r = 0.90, P < 0.001) for patients., Conclusion: This study describes and evaluates a novel noncontact monitoring system suitable for continuous monitoring of key respiratory parameters for disease assessment of critically ill patients., (© 2020 American Association of Physicists in Medicine.)

Featured Application: This review provides an overview of commercially available 3D surface imaging systems that provide body composition estimates for practitioners and researchers, encouragement for system manufacturers to increase the public availability of user and system details, and a call for standardisation within this field. Recent literature has suggested 3D surface imaging to be a potential method of estimating body composition. The aim of this study was to provide an overview of commercially available 3D surface imaging systems that provide body composition estimates. User and system details of complete commercially available whole body 3D surface imaging systems, which estimate body composition, were collated from May to June 2022. Six 3D body surface imaging systems were identified, each of which provided varying amounts of user and system details. As this information is necessary to ensure the correct selection of system, appropriate use, and interpretation of outputs, manufacturers should seek to publicly present more detailed user and system details, international standards groups and training associations should seek to encourage standardisation, and practitioners and researchers should request additional details where necessary and validate their system prior to use, and end users should cautiously interpret outputs without the availability of comprehensive user and system details. [ABSTRACT FROM AUTHOR]

Aim: This study aims to evaluate optimized breast implant surface-structure analysis by comparing high-end ultrasound technology with a new high frequency technique. This comparative study used new breast implants with different surfaces in an in vitro setting., Methods: Nine idle silicon or polyurethane (PU) breast implants were examined by two investigators in an experimental in vitro study using two high-end ultrasound devices with multi-frequency transducers (6-15 MHz, 9-16 MHz, 12.5-33 MHz).The ultrasound B-Mode was optimized using tissue harmonic imaging (THI), speckle reduction imaging (SRI, level 0-5), cross beam (high, medium, low) and photopic.Using a standardized ultrasound protocol, the implants were examined in the middle (point of highest projection) and lateral, by two independent examiners.Image evaluation was performed on anonymized digital images in the PACS. The aim was to achieve an artifact-free recording of the surface structure, the surface coating, the total image structures and, as far as possible, an artifact-free internal representation of the implants.For independent surface evaluation a score was used (0 = undetectability of surface structures, rich in artifacts, 5 = best possible, artifact free image quality)., Results: The quality of ultrasound imaging of breast implant surfaces after the optimization of B-Scan differed significantly comparing high-end ultrasound technology with modern high-frequency ultrasound technology (p < 0,05).The following setting has been found to be the best setting with the highest image quality:B-Mode, SRI value 3, Crossbeam high level with color coded imaging for B- mode. In the total examined frequency range of 6-33 MHz, the highest image quality was found in the average frequency range of 12.5-33 MHz at both measured points. For both devices, device 1 (high-end) and device 2 (high frequency) ultrasound, the image quality was in the12.5-33 MHz frequency range with an average image quality of 3.236. It was significantly higher, than in the lower frequency ranges and the same frequency range with THI. (p < 0,05).  The image quality of the high-end sonography device was superior to the conventional high-frequency ultrasound device in all frequency ranges., Conclusion: High-end ultrasound imaging technology was superior in the quality of implant surface evaluation in comparison to high-frequency ultrasound sonography. The gained knowledge can serve as a basis for further multicenter clinical application and studies with the aim to develop an objective, precise tool to evaluate the implant and the surrounding tissue with ultrasound.

Combining WO 3 with suitable materials to form heterojunction is essential to overcome the limitations of WO 3 to enhance its photoelectrochemical (PEC) water splitting activity. Moreover, a clear understanding of photo-response and charge behavior of materials could lead to the rational design of efficient photoelectrodes. Given this, an efficient strategy is applied to fabricate WO 3 heterojunction with nitrogen-doped carbon dots (NCDs) and in-depth characterization to investigate the surface charge dynamics using nano imaging in a relation to the enhanced PEC water splitting activity. The optimized NCDs loading to the WO 3 NRs exhibited the enhanced photocurrent density of 1.54 mA cm−2 at 1.23V vs RHE under AM 1.5 G illumination, highest IPCE of ~82 % (at 308.32 nm). The Kelvin probe force microscopy and electrostatic force microscopy reveal that after loading NCDs to the WO 3 , a relatively smooth charge transport has been observed, which improves the PEC. Furthermore, this work demonstrates the effect of photogenerated charges caused by the NCDs that assist in enhancing the increased photocurrent, hydrogen production efficiency, and stability of the PEC water splitting system. Significantly, the nano imaging characterization utilized in this work could be extended to various photoanodes to study the surface charge dynamics. [Display omitted] • WO 3 NRs/NCDs heterojunction was proposed for water splitting applications. • NCD on WO 3 suppresses charge recombination and decreases charge transfer resistance. • Enhanced photocurrent, IPCE, and H 2 production was achieved upon NCD sensitization. • Nanoscale surface imaging was performed to understand insights of carrier dynamics. [ABSTRACT FROM AUTHOR]

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Surface imaging is an emerging radiation therapy technique that aids in the setup of patients for treatment and acts as an intrafraction monitoring system. Although the technology offers several advantages for staff and patients, it can be challenging to put into practice. With appropriate training and implementation, radiation oncology staff can use surface imaging to improve patient care and comfort while reducing dose to the patient. This article describes surface imaging, its uses, and its applications for treating specific anatomy. [ABSTRACT FROM AUTHOR]

• A novel high-speed 3D surface imaging technique using deep learning is proposed. • The phase can be extracted from a single fringe image accurately. • In contrast to Fourier-transform methods, phase accuracy can be improved by near 50. • 3D results of this method can be comparable to the one with phase-shifting methods. How to obtain object information as rich as possible, with the highest possible speed and accuracy from recorded optical signals, has been a crucial issue to the pursuit of powerful imaging technologies. Nowadays, the speed of ultra-fast photography can exceed one quadrillion. However, it can record only two-dimensional images which lack the depth information, greatly limiting our ability to perceive and to understand the complex real-world objects. Inspired by recent successes of deep learning methods in computer vision, we present a novel high-speed three-dimensional (3D) surface imaging approach named micro deep learning profilometry (μ DLP) using the structured light illumination. With a properly trained deep neural network, the phase information is predicted from a single fringe image and then can be converted into the 3D shape. Our experiments demonstrate that μ DLP can faithfully retrieve the geometry of dynamic objects at 20,000 frames per second. Moreover, comparative results show that μ DLP has superior performance in terms of the phase accuracy, reconstruction efficiency, and the ease of implementation over widely used Fourier-transform-based fast 3D imaging techniques, verifying that μ DLP is a powerful high-speed 3D surface imaging approach. [ABSTRACT FROM AUTHOR]

Backgroundobjective: Post-oncological nasal reconstruction presents both aesthetic and functional challenges. While established methods exist for quantitatively evaluating functional results following surgery, equivalent systems for assessing aesthetic outcomes are lacking. Three-dimensional (3D) photogrammetry, already used in maxillofacial and orthodontic surgery for aesthetic evaluation, overcomes some limitations of traditional methods like direct anthropometry. However, its applicability in oncological facial reconstruction has not yet been explored. In our study, we applied the 3dMDtrio™ system for the quantitative analysis of line and surface modifications following nasal reconstruction. Methods: We conducted a prospective observational study enrolling patients with skin neoplasms located on the nose undergoing surgical excision and reconstruction. Using the 3dMDtrio™ system, we measured the dimensions and projections of nasal surfaces and the positions of specific landmarks before and after surgery. The surface measurements were then correlated with aesthetic evaluations performed by three plastic surgeons, not involved in the procedure, using a 5-point Likert scale. Results: We included 33 patients with a mean age of 71 years, ranging from 40 to 94. We obtained complete documentation of all postoperative measurements for 21 patients. We observed significant changes in the positions of the landmarks post-surgery, limited to the right ala and nasion. The average nasal surface area was 4674.41 mm2 ± 477.24 mm2 before surgery and 4667.95 mm2 ± 474.12 mm2 after surgery, with no significant discrepancies. The evaluation using the Likert scale revealed an average score of 3.04 ± 0.48, with a significant negative correlation to the measured surface changes. Conclusion: Our findings suggest that 3D photogrammetry can be considered a valid method for objectively assessing volumetric changes associated with post-oncological nasal reconstructive surgery.

Background:. Autologous breast reconstruction can be performed for breasts with ptosis to a certain extent, but if patients desire to correct ptosis, mastopexy of the contralateral breast is indicated. However, accurate prediction of post-mastopexy breast shape is difficult to make, and symmetrical breast reconstruction requires certain experience. We have previously reported the use of three-dimensional (3D) imaging and printing technologies in deep inferior epigastric artery perforator (DIEP) flap breast reconstruction. In the present study, these technologies were applied to the reconstruction of breasts with ptosis. Methods:. Eight breast cancer patients with ptotic breasts underwent two-stage unilateral DIEP flap breast reconstruction. In the initial surgery, tissue expander (TE) placement and contralateral mastopexy are performed simultaneously. Four to six months later, 3D bilateral breast imaging is performed after confirming that the shape of the contralateral breast (post-mastopexy) is somewhat stabilized, and a 3D-printed breast mold is created based on the mirror image of the shape of the contralateral breast acquired using analytical software. Then, DIEP flap surgery is performed, where the breast mold is used to determine the required flap volume and to shape the breast mound. Results:. All flaps were engrafted without any major perioperative complications during both the initial and DIEP flap surgeries. Objective assessment of cosmetic outcome revealed that good breast symmetry was achieved in all cases. Conclusions:. The method described here may allow even inexperienced surgeons to achieve reconstruction of symmetrical, non-ptotic breasts with ease and in a short time. While the requirement of two surgeries is a potential disadvantage, our method will be particularly useful in cases involving TEs, i.e., delayed reconstruction or immediate reconstruction involving significant skin resection.

Purpose: This study aimed to evaluate and compare different system calibration methods from a large cohort of systems to establish a commissioning procedure for surface-guided frameless cranial stereotactic radiosurgery (SRS) with intrafractional motion monitoring and gating. Using optical surface imaging (OSI) to guide non-coplanar SRS treatments, the determination of OSI couch-angle dependency, baseline drift, and gated-delivered-dose equivalency are essential., Methods: Eleven trained physicists evaluated 17 OSI systems at nine clinical centers within our institution. Three calibration methods were examined, including 1-level (2D), 2-level plate (3D) calibration for both surface image reconstruction and isocenter determination, and cube phantom calibration to assess OSI-megavoltage (MV) isocenter concordance. After each calibration, a couch-angle dependency error was measured as the maximum registration error within the couch rotation range. A head phantom was immobilized on the treatment couch and the isocenter was set in the middle of the brain, marked with the room lasers. An on-site reference image was acquired at couch zero, the facial region of interest (ROI) was defined, and static verification images were captured every 10° for 0°-90° and 360°-270°. The baseline drift was assessed with real-time monitoring of the motionless phantom over 20 min. The gated-delivered-dose equivalency was assessed using the electron portal imaging device and gamma test (1%/1mm) in reference to non-gated delivery., Results: The maximum couch-angle dependency error occurs in longitudinal and lateral directions and is reduced significantly (P < 0.05) from 1-level (1.3 ± 0.4 mm) to 2-level (0.8 ± 0.3 mm) calibration. The MV cube calibration does not further reduce the couch-angle dependency error (0.8 ± 0.2 mm) on average. The baseline drift error plateaus at 0.3 ± 0.1 mm after 10 min. The gated-delivered-dose equivalency has a >98% gamma-test passing rate., Conclusion: A commissioning method is recommended using the 3D plate calibration, which is verified by radiation isocenter and validated with couch-angle dependency, baseline drift, and gated-delivered-dose equivalency tests. This method characterizes OSI uncertainties, ensuring motion-monitoring accuracy for SRS treatments., (© 2021 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)