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Lai J, Luo Z, Jiang L, Hu H, Gao C, Zhang C, Chen L, Wu J, Wu Z. Skin marker combined with surface-guided auto-positioning for breast DIBH radiotherapy daily initial patient setup: An optimal schedule for both accuracy and efficiency. J Appl Clin Med Phys 2024; 25:e14319. [PMID: 38522035 DOI: 10.1002/acm2.14319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 01/31/2024] [Accepted: 02/12/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND AND PURPOSE By employing three surface-guided radiotherapy (SGRT)-assisted positioning methods, we conducted a prospective study of patients undergoing SGRT-based deep inspiration breath-hold (DIBH) radiotherapy using a Sentine/Catalys system. The aim of this study was to optimize the initial positioning workflow of SGRT-DIBH radiotherapy for breast cancer. MATERIALS AND METHODS A total of 124 patients were divided into three groups to conduct a prospective comparative study of the setup accuracy and efficiency for the daily initial setup of SGRT-DIBH breast radiotherapy. Group A was subjected to skin marker plus SGRT verification, Group B underwent SGRT optical feedback plus auto-positioning, and Group C was subjected to skin marker plus SGRT auto-positioning. We evaluated setup accuracy and efficiency using cone-beam computed tomography (CBCT) verification data and the total setup time. RESULTS In groups A, B, and C, the mean and standard deviation of the translational setup-error vectors were small, with the highest values of the three directions observed in group A (2.4 ± 1.6, 2.9 ± 1.8, and 2.8 ± 2.1 mm). The rotational vectors in group B (1.8 ± 0.7°, 2.1 ± 0.8°, and 1.8 ± 0.7°) were significantly larger than those in groups A and C, and the Group C setup required the shortest amount of time, at 1.5 ± 0.3 min, while that of Group B took the longest time, at 2.6 ± 0.9 min. CONCLUSION SGRT one-key calibration was found to be more suitable when followed by skin marker/tattoo and in-room laser positioning, establishing it as an optimal daily initial set-up protocol for breast DIBH radiotherapy. This modality also proved to be suitable for free-breathing breast cancer radiotherapy, and its widespread clinical use is recommended.
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Affiliation(s)
- Jianjun Lai
- Instiute of Intelligent Control and Robotics, Hangzhou Dianzi University, Hangzhou, China
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Zhizeng Luo
- Instiute of Intelligent Control and Robotics, Hangzhou Dianzi University, Hangzhou, China
| | - Lu Jiang
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Haili Hu
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Chang Gao
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Chuanfeng Zhang
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Liting Chen
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Jing Wu
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
| | - Zhibing Wu
- Department of Radiation Oncology, Zhejiang Hospital, Hangzhou, China
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Zhao H, Sarkar V, St James S, Paxton A, Su FF, Price RG, Dial C, Poppe M, Gaffney D, Salter B. Verification of surface-guided radiation therapy (SGRT) alignment for proton breast and chest wall patients by comparison to CT-on-rails and kV-2D alignment. J Appl Clin Med Phys 2024; 25:e14263. [PMID: 38268200 PMCID: PMC10860439 DOI: 10.1002/acm2.14263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND Surface-guided radiation therapy (SGRT) systems have been widely installed and utilized on linear accelerators. However, the use of SGRT with proton therapy is still a newly developing field, and published reports are currently very limited. PURPOSE To assess the clinical application and alignment agreement of SGRT with CT-on-rails (CTOR) and kV-2D image-guided radiation therapy (IGRT) for breast treatment using proton therapy. METHODS Four patients receiving breast or chest wall treatment with proton therapy were the subjects of this study. Patient #1's IGRT modalities were a combination of kV-2D and CTOR. CTOR was the only imaging modality for patients #2 and #3, and kV-2D was the only imaging modality for patient #4. The patients' respiratory motions were assessed using a 2-min surface position recorded by the SGRT system during treatment. SGRT offsets reported after IGRT shifts were recorded for each fraction of treatment. The agreement between SGRT and either kV-2D or CTOR was evaluated. RESULTS The respiratory motion amplitude was <4 mm in translation and <2.0° in rotation for all patients. The mean and maximum amplitude of SGRT offsets after application of IGRT shifts were ≤(2.6 mm, 1.6° ) and (6.8 mm, 4.5° ) relative to kV-2D-based IGRT; ≤(3.0 mm, 2.6° ) and (5.0 mm, 4.7° ) relative to CTOR-based IGRT without breast tissue inflammation. For patient #3, breast inflammation was observed for the last three fractions of treatment, and the maximum SGRT offsets post CTOR shifts were up to (14.0 mm, 5.2° ). CONCLUSIONS Due to the overall agreement between SGRT and IGRT within reasonable tolerance, SGRT has the potential to serve as a valuable auxiliary IGRT tool for proton breast treatment and may improve the efficiency of proton breast treatment.
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Affiliation(s)
- Hui Zhao
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Vikren Sarkar
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Sara St James
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Adam Paxton
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | | | - Ryan G. Price
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Christian Dial
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Matthew Poppe
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - David Gaffney
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
| | - Bill Salter
- Radiation Oncology DepartmentUniversity of UtahSalt Lake CityUtahUSA
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Kubo T, Kurokawa C, Inoue T, Fujii T, Miyaura K, Shinjo H, Kagami Y, Shikama N. Analysis of applicator displacement in accelerated partial breast irradiation using a strut-based design brachytherapy applicator. Brachytherapy 2023; 22:655-664. [PMID: 37455152 DOI: 10.1016/j.brachy.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/14/2023] [Accepted: 05/26/2023] [Indexed: 07/18/2023]
Abstract
PURPOSE This study aimed to identify factors associated with strut-adjusted volume implant (SAVI) displacement in accelerated partial breast irradiation (APBI) using a SAVI device. METHODS AND MATERIALS We retrospectively analyzed computed tomography scans taken at the time of treatment planning and immediately before treatment in 61 patients (median age; 55 years, range; 40-85) treated with SAVI and determined the amount of SAVI displacement that occurred between the time from planning to the treatment. The displacement was calculated for the CT axis and SAVI axis, which is related to the SAVI structure. To investigate the cause of the displacement, multivariate analysis was performed on the calculated standard deviation and the insertion angle of SAVI with respect to the sternum in each cross-section, breast density, amount of air around the SAVI, and SAVI length inside the patient to obtain the β coefficient (p-value). RESULTS On the CT coordinate system, positive correlations were observed between the SAVI insertion angle and air volume in the lateral (β coefficient:0.255-0.483) and rotational directions (β coefficient:0.341). On the SAVI coordinate system, positive correlations were observed between the SAVI insertion angle and air volume in all lateral (β coefficient:0.270-0.354) and rotational directions (β coefficient:0.294). A negative correlation was observed between the SAVI length inside the patient and the rotational direction (β coefficient: -0.262). CONCLUSION SAVI insertion angle, the amount of the air outside SAVI and SAVI insertion length are factors which affect the displacement of the applicator. From the results, the applicator displacement and rotation must be <3 mm and 10o in order to meet all the dose criteria. Thus, we should be aware of these factors during insertion of the device to avoid the problem in treatment delivery for the APBI.
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Affiliation(s)
- Tadashi Kubo
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, Tokyo, Japan; Department of Radiotechnology, Showa University Northern Yokohama Hospital, Kanagawa, Japan.
| | - Chie Kurokawa
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
| | - Tatsuya Inoue
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
| | - Tomoki Fujii
- Department of Radiotechnology, Showa University Hospital, Tokyo, Japan
| | - Kazunori Miyaura
- Graduate School of Health Sciences, Showa University, Tokyo, Japan
| | - Hidenori Shinjo
- Division of radiation oncology, Department of Radiology, Showa University School of Medicine, Tokyo, Japan
| | - Yoshikazu Kagami
- Division of radiation oncology, Department of Radiology, Showa University School of Medicine, Tokyo, Japan
| | - Naoto Shikama
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
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Bellala R, Kuppusamy A, Bellala VM, Tyagi T, Manoharan S, Gangarapu G, Bellala R. Review of clinical applications and challenges with surface-guided radiation therapy. J Cancer Res Ther 2023; 19:1160-1169. [PMID: 37787279 DOI: 10.4103/jcrt.jcrt_1147_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Aim To evaluate the use of this new technique, surface-guided radiotherapy (SGRT), for patient setup and motion management in various cancers. Materials and Methods Data was collected from 533 patients, who received treatment in our hospital for various malignancies using SGRT from October 2019 to April 2021. We studied patient setup, interfraction position, and patient position during the breath-hold (BH) technique. The main advantage of SGRT is that, it is completely non-invasive and uses visible light to compare the patient's skin surface in the treatment room and planned treatment position. In this analysis, Monaco 5.51.10 (Elekta) treatment planning system, Versa HD Linear Accelerator, and AlignRT 6.2 (Vision RT) SGRT system were used. Results With SGRT, treatment setup time can be reduced with more precision and techniques like Deep inspiration breathhold (DIBH) can be done with very good compliance. Conclusion SGRT has shown improved accuracy in patient setup compared to conventional laser setup. The daily kilo voltage imaging frequency can be reduced; it helps in reducing additional radiation exposure due to imaging. SGRT has demonstrated reproducibility with adequate accuracy in BH treatments in DIBH for breast and SBRT.
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Affiliation(s)
- Ravishankar Bellala
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Anandakrishnan Kuppusamy
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Venkat Madhavi Bellala
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Tulika Tyagi
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Surendhiran Manoharan
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Gunasekhar Gangarapu
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
| | - Rishik Bellala
- Department of Radiation Oncology, Omega Hospital, Arilova, Health City, Chinagadili, Visakhapatnam, Andhra Pradesh, India
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Svestad JG, Heydari M, Mikalsen SG, Flote VG, Nordby F, Hellebust TP. Surface-guided positioning eliminates the need for skin markers in radiotherapy of right sided breast cancer: A single center randomized crossover trial. Radiother Oncol 2022; 177:46-52. [PMID: 36309152 DOI: 10.1016/j.radonc.2022.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 09/20/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND PURPOSE To prospectively investigate whether surface guided setup of right sided breast cancer patients can increase efficiency and accuracy compared to traditional skin marker/tattoo based setup. MATERIAL AND METHODS Twenty-five patients were included in this study. Each patient was positioned using skin marks and tattoos (procedure A) for half of the fractions and surface guidance using AlignRT (procedure B) for the other half of the fractions. The order of the two procedures was randomized. Pretreatment CBCT was acquired at every fraction for both setup procedures. A total of ten time points were recorded during every treatment session. Applied couch shifts after CBCT match were recorded and used for potential error calculations if no CBCT had been used. RESULTS In the vertical direction procedure B showed significant smaller population based systematic (Ʃ) and random (σ) errors. However, a significant larger systematic error on the individual patient level (M) was also shown. This was found to be due to patient relaxation between setup and CBCT matching. Procedure B also showed a significant smaller random error in the lateral direction, while no significant differences were seen in the longitudinal direction. No significant difference in setup time was found between the two procedures. CONCLUSION Setup of right sided breast cancer patients using surface guidance yields higher accuracy than setup using skin marks/tattoos and lasers with the same setup time. Patient alignment for this patient group can safely be done without the use of permanent tattoos and skin marks when utilizing surface-guided patient positioning. However, CBCT should still be used as final setup verification.
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Affiliation(s)
| | - Mojgan Heydari
- Department of Medical Physics, Oslo University Hospital, Oslo, Norway
| | | | | | - Fredrik Nordby
- Department of Oncology, Oslo University Hospital, Oslo, Norway
| | - Taran Paulsen Hellebust
- Department of Medical Physics, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Norway.
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Machine learning-based treatment couch parameter prediction in support of surface guided radiation therapy. Tech Innov Patient Support Radiat Oncol 2022; 23:15-20. [PMID: 36039333 PMCID: PMC9418545 DOI: 10.1016/j.tipsro.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/02/2022] [Accepted: 08/09/2022] [Indexed: 11/30/2022] Open
Abstract
Optimizing surface guided radiation therapy workflow. Machine learning-based automatic treatment couch parameters prediction. quality assurance for patient positioning.
Purpose A fully independent, machine learning-based automatic treatment couch parameters prediction was developed to support surface guided radiation therapy (SGRT)-based patient positioning protocols. Additionally, this approach also acts as a quality assurance tool for patient positioning. Materials/Methods Setup data of 183 patients, divided into four different groups based on used setup devices, was used to calculate the difference between the predicted and the acquired treatment couch value. Results Couch parameters can be predicted with high precision μ=0.90,σ=0.92. A significant difference (p < 0.01) between the variances of Lung and Brain patients was found. Outliers were not related to the prediction accuracy, but are due to inconsistencies during initial patient setup. Conclusion Couch parameters can be predicted with high accuracy and can be used as starting point for SGRT-based patient positioning. In case of large deviations (>1.5 cm), patient setup has to be verified to optimally use the surface scanning system.
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Song Y, Zhai X, Liang Y, Zeng C, Mueller B, Li G. Evidence-based region of interest (ROI) definition for surface-guided radiotherapy (SGRT) of abdominal cancers using deep-inspiration breath-hold (DIBH). J Appl Clin Med Phys 2022; 23:e13748. [PMID: 35946900 PMCID: PMC9680570 DOI: 10.1002/acm2.13748] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/27/2022] [Accepted: 07/20/2022] [Indexed: 01/19/2023] Open
Abstract
To define and evaluate the appropriate abdominal region of interest (ROI) as a surrogate of diaphragm positioning in deep-inspiration breath-hold (DIBH) for surface-guided radiotherapy (SGRT) of abdominal cancers using 3D optical surface imaging (OSI). Six potential abdominal ROIs were evaluated to calculate their correlations with the diaphragm position using 4DCT images of 20 abdominal patients. Twelve points of interest (POIs) were defined (six on the central soft tissue and six on the bilateral ribs) at three superior-inferior levels, and different sub-groups represented different ROIs. ROI-1 was the largest, containing all 12 POIs from the xiphoid to the umbilicus and between the lateral body midlines while ROI-2 had only eight inferior POIs, ROI-3 had six lateral POIs, and ROI-4 had four superior-lateral POIs over the ribs, ROI-5 contained six central and two most inferior-lateral POIs and ROI-6 contained six central and four inferior-lateral POIs. Internally, the right diaphragm dome was used to represent its positions in 4DCT (0% and 50% within the cycle). The Pearson correlation coefficients were calculated between the diaphragm dome and all 12 external POIs individually or grouped as six ROIs. The quality of the abdominal ROIs was evaluated as potential internal surrogates and, therefore, potential ROIs for SGRT DIBH setup. The four most inferior POIs show the highest mean correlation (r = 0.75) with diaphragmatic motion, and the correlation decreases as POIs move superiorly. The mean correlations are the highest for ROIs with little or no rib support: r = 0.67 for ROI-2, r = 0.64 for ROI-5, and r = 0.63 for ROI-6, while lower for ROIs with rib support: ROI-1 has r = 0.60, ROI-3 has r = 0.50, and ROI-4 has only r = 0.28. This study demonstrates that the rectangular/triangular soft-tissue ROI (with little rib support) is an optimal surrogate for body positioning and diaphragmatic motion, even when treating tumors under the rib cage. This evidence-based ROI definition should be utilized when treating abdominal cancers with free-breathing (FB) and/or DIBH setup.
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Affiliation(s)
- Yulin Song
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Xingchen Zhai
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Yubei Liang
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Chuan Zeng
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Boris Mueller
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Guang Li
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
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Li G. Advances and potential of optical surface imaging in radiotherapy. Phys Med Biol 2022; 67:10.1088/1361-6560/ac838f. [PMID: 35868290 PMCID: PMC10958463 DOI: 10.1088/1361-6560/ac838f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 07/22/2022] [Indexed: 11/12/2022]
Abstract
This article reviews the recent advancements and future potential of optical surface imaging (OSI) in clinical applications as a four-dimensional (4D) imaging modality for surface-guided radiotherapy (SGRT), including OSI systems, clinical SGRT applications, and OSI-based clinical research. The OSI is a non-ionizing radiation imaging modality, offering real-time 3D surface imaging with a large field of view (FOV), suitable for in-room interactive patient setup, and real-time motion monitoring at any couch rotation during radiotherapy. So far, most clinical SGRT applications have focused on treating superficial breast cancer or deep-seated brain cancer in rigid anatomy, because the skin surface can serve as tumor surrogates in these two clinical scenarios, and the procedures for breast treatments in free-breathing (FB) or at deep-inspiration breath-hold (DIBH), and for cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) are well developed. When using the skin surface as a body-position surrogate, SGRT promises to replace the traditional tattoo/laser-based setup. However, this requires new SGRT procedures for all anatomical sites and new workflows from treatment simulation to delivery. SGRT studies in other anatomical sites have shown slightly higher accuracy and better performance than a tattoo/laser-based setup. In addition, radiographical image-guided radiotherapy (IGRT) is still necessary, especially for stereotactic body radiotherapy (SBRT). To go beyond the external body surface and infer an internal tumor motion, recent studies have shown the clinical potential of OSI-based spirometry to measure dynamic tidal volume as a tumor motion surrogate, and Cherenkov surface imaging to guide and assess treatment delivery. As OSI provides complete datasets of body position, deformation, and motion, it offers an opportunity to replace fiducial-based optical tracking systems. After all, SGRT has great potential for further clinical applications. In this review, OSI technology, applications, and potential are discussed since its first introduction to radiotherapy in 2005, including technical characterization, different commercial systems, and major clinical applications, including conventional SGRT on top of tattoo/laser-based alignment and new SGRT techniques attempting to replace tattoo/laser-based setup. The clinical research for OSI-based tumor tracking is reviewed, including OSI-based spirometry and OSI-guided tumor tracking models. Ongoing clinical research has created more SGRT opportunities for clinical applications beyond the current scope.
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Affiliation(s)
- Guang Li
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, United States of America
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Residual image registration error by fiducial markers in accelerated partial breast irradiation using C-arm linac: a phantom study. Phys Eng Sci Med 2022; 45:769-779. [PMID: 35657476 DOI: 10.1007/s13246-022-01142-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
Abstract
External beam accelerated partial breast irradiation (APBI) is an alternative treatment for patients with early-stage breast cancer. The efficacy of image-guided radiotherapy (IGRT) using fiducial markers, such as gold markers or surgical clips, has been demonstrated. However, the effects of respiratory motion during a single fraction have not been reported. This study aimed to evaluate the residual image registration error of fiducial marker-based IGRT by respiratory motion and propose a suitable treatment strategy. We developed an acrylic phantom embedded with surgical clips to verify the registration error under moving conditions. The frequency of the phase difference in the respiratory cycle due to sequential acquisition was verified in a preliminary study. Fiducial marker-based IGRT was then performed in ten scenarios. The residual registration error (RRE) was calculated on the basis of the differences in the coordinates of clips between the true position if not moved and the last position. The frequencies of the phase differences in 0.0-0.99, 1.0-1.99, 2.0-2.99, 3.0-3.99, and 4.0-5.0 mm were 23%, 24%, 22%, 20%, and 11%, respectively. When assuming a clinical case, the mean RREs for all directions were within 1.0 mm, even if respiratory motion of 5 mm existed in two axes. For APBI with fiducial marker-based IGRT, the introduction of an image registration strategy that employs stepwise couch correction using at least three orthogonal images should be considered.
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Li C, Lu Z, He M, Sui J, Lin T, Xie K, Sun J, Ni X. Augmented reality-guided positioning system for radiotherapy patients. J Appl Clin Med Phys 2022; 23:e13516. [PMID: 34985188 PMCID: PMC8906221 DOI: 10.1002/acm2.13516] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/18/2021] [Accepted: 12/15/2021] [Indexed: 01/22/2023] Open
Abstract
In modern radiotherapy, error reduction in the patients’ daily setup error is important for achieving accuracy. In our study, we proposed a new approach for the development of an assist system for the radiotherapy position setup by using augmented reality (AR). We aimed to improve the accuracy of the position setup of patients undergoing radiotherapy and to evaluate the error of the position setup of patients who were diagnosed with head and neck cancer, and that of patients diagnosed with chest and abdomen cancer. We acquired the patient's simulation CT data for the three‐dimensional (3D) reconstruction of the external surface and organs. The AR tracking software detected the calibration module and loaded the 3D virtual model. The calibration module was aligned with the Linac isocenter by using room lasers. And then aligned the virtual cube with the calibration module to complete the calibration of the 3D virtual model and Linac isocenter. Then, the patient position setup was carried out, and point cloud registration was performed between the patient and the 3D virtual model, such the patient's posture was consistent with the 3D virtual model. Twenty patients diagnosed with head and neck cancer and 20 patients diagnosed with chest and abdomen cancer in the supine position setup were analyzed for the residual errors of the conventional laser and AR‐guided position setup. Results show that for patients diagnosed with head and neck cancer, the difference between the two positioning methods was not statistically significant (P > 0.05). For patients diagnosed with chest and abdomen cancer, the residual errors of the two positioning methods in the superior and inferior direction and anterior and posterior direction were statistically significant (t = −5.80, −4.98, P < 0.05). The residual errors in the three rotation directions were statistically significant (t = −2.29 to −3.22, P < 0.05). The experimental results showed that the AR technology can effectively assist in the position setup of patients undergoing radiotherapy, significantly reduce the position setup errors in patients diagnosed with chest and abdomen cancer, and improve the accuracy of radiotherapy.
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Affiliation(s)
- Chunying Li
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Zhengda Lu
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Mu He
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Jianfeng Sui
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Tao Lin
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Kai Xie
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Jiawei Sun
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
| | - Xinye Ni
- Department of Radiotherapy, Changzhou Second People's Hospital, Nanjing Medical University, Changzhou, China.,Laboratory of Medical Physics Center, Nanjing Medical University, Jiangning District, Nanjing, China.,Changzhou Key Laboratory of Medical Physics, Changzhou, China
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11
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Wang G, Song X, Li G, Duan L, Li Z, Dai G, Bai L, Xiao Q, Zhang X, Song Y, Bai S. Correlation of Optical Surface Respiratory Motion Signal and Internal Lung and Liver Tumor Motion: A Retrospective Single-Center Observational Study. Technol Cancer Res Treat 2022; 21:15330338221112280. [PMID: 35791642 PMCID: PMC9272160 DOI: 10.1177/15330338221112280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Purpose: Surface-guided radiation therapy (SGRT) application has limitations. This study aimed to explore the relationship between patient characteristics and their external/internal correlation to qualitatively assess the external/internal correlation in a particular patient. Methods: Liver and lung cancer patients treated with radiotherapy in our institution were retrospectively analyzed. The external/internal correlation were calculated with Spearman correlation coefficient (SCC) and SCC after support vector regression (SVR) fitting (SCCsvr). The relationship between the external/internal correlation and magnitudes of motion of the tumor and external marker (Ai, Ae), tumor volume Vt, patient age, gender, and tumor location were explored. Results: The external/internal motions of liver and lung cancer patients were strongly correlated in the S-I direction, with mean SCCsvr values of 0.913 and 0.813. The correlation coefficients between the external/internal correlations and the patients’ characteristics (Ai, Ae, Vt, and age) were all smaller than 0.5; Ai, Ae and liver tumor volumes were positively correlated with the strength of the external/internal correlation, while lung tumor volumes and patient age were negative. The external/internal correlations in males and females were roughly equal, and the external/internal correlations in patients with peripheral lung cancers were stronger than those in patients with central lung cancers. Conclusion: The external/internal correlation shows great individual differences. The effects of Ai, Ae, Vt, and age are weakly to moderately correlated. Our results suggest the necessity of individualized assessment of patient's external/internal motion correlation prior to the application of SGRT technique for breath motion monitoring.
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Affiliation(s)
- Guangyu Wang
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Xinyu Song
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Guangjun Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Lian Duan
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Zhibin Li
- Department of Radiation Oncology, 74566The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Guyu Dai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Long Bai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Qing Xiao
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Xiangbin Zhang
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Ying Song
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
| | - Sen Bai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, 12530Sichuan University, Chengdu, China
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Improvement of patient localization repeatability using a light-section based optical surface guidance system in a pre-positioning procedure. Cancer Radiother 2021; 26:547-556. [PMID: 34740524 DOI: 10.1016/j.canrad.2021.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/29/2021] [Accepted: 07/31/2021] [Indexed: 11/22/2022]
Abstract
PURPOSE Surface-guided radiotherapy is useful for the pre-positioning and monitoring of radiotherapy. The purpose of this study was to investigate the impact of surface guidance on the repeatability of patient localization and to estimate the specific point at which high positional errors occur. MATERIALS AND METHODS Ten patients without the VOXELAN system (non-VXLN group) and 10 patients with the VOXELAN as the pre-positioning procedure (VXLN group) were included in this analysis. Twelve regions of interest (ROI) were defined in all the patients to verify any misalignment during radiotherapy. Thirteen ROIs were defined on the isocenter. RESULTS Compared with the non-VXLN group, the translational positional errors of the VXLN group were the same for all the ROIs. The mean translational positional errors of the VXLN group in the longitudinal direction were approximately 0.1mm, and the standard deviation was the largest among the three directions in all the ROIs. The magnitude of the standard deviation in the non-VXLN group varied independently of the ROI and direction. The standard deviations of the VXLN group in the longitudinal direction were large in all the ROIs, while the standard deviations in the vertical and lateral directions were small. CONCLUSION Pre-positioning with a surface guidance system reduced the body twist and rotation, which could not be corrected by image-guided radiotherapy alone. Since the VOXELAN can detect positioning errors quickly and without additional radiation exposure to the patient, it can be used as a tool for pre-positioning in radiotherapy.
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Lee SK, Huang S, Zhang L, Ballangrud AM, Aristophanous M, Cervino Arriba LI, Li G. Accuracy of surface-guided patient setup for conventional radiotherapy of brain and nasopharynx cancer. J Appl Clin Med Phys 2021; 22:48-57. [PMID: 33792186 PMCID: PMC8130230 DOI: 10.1002/acm2.13241] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/16/2021] [Accepted: 03/14/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose To evaluate the accuracy of surface‐guided radiotherapy (SGRT) in cranial patient setup by direct comparison between optical surface imaging (OSI) and cone‐beam computed tomography (CBCT), before applying SGRT‐only setup for conventional radiotherapy of brain and nasopharynx cancer. Methods and Materials Using CBCT as reference, SGRT setup accuracy was examined based on 269 patients (415 treatments) treated with frameless cranial stereotactic radiosurgery (SRS) during 2018‐2019. Patients were immobilized in customized head molds and open‐face masks and monitored using OSI during treatment. The facial skin area in planning CT was used as OSI region of interest (ROI) for automatic surface alignment and the skull was used as the landmark for automatic CBCT/CT registration. A 6 degrees of freedom (6DOF) couch was used. Immediately after CBCT setup, an OSI verification image was captured, recording the SGRT setup differences. These differences were analyzed in 6DOFs and as a function of isocenter positions away from the anterior surface to assess OSI‐ROI bias. The SGRT in‐room setup time was estimated and compared with CBCT and orthogonal 2D kilovoltage (2DkV) setups. Results The SGRT setup difference (magnitude) is found to be 1.0 ± 2.5 mm and 0.1˚±1.4˚ on average among 415 treatments and within 5 mm/3˚ with greater than 95% confidence level (P < 0.001). Outliers were observed for very‐posterior isocenters: 15 differences (3.6%) are >5.0mm and 9 (2.2%) are >3.0˚. The setup differences show minor correlations (|r| < 0.45) between translational and rotational DOFs and a minor increasing trend (<1.0 mm) in the anterior‐to‐posterior direction. The SGRT setup time is 0.8 ± 0.3 min, much shorter than CBCT (5 ± 2 min) and 2DkV (2 ± 1 min) setups. Conclusion This study demonstrates that SGRT has sufficient accuracy for fast in‐room patient setup and allows real‐time motion monitoring for beam holding during treatment, potentially useful to guide radiotherapy of brain and nasopharynx cancer with standard fractionation.
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Affiliation(s)
- Sang Kyu Lee
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sheng Huang
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lei Zhang
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ase M Ballangrud
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Michalis Aristophanous
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Laura I Cervino Arriba
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Guang Li
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Wang G, Li Z, Li G, Dai G, Xiao Q, Bai L, He Y, Liu Y, Bai S. Real-time liver tracking algorithm based on LSTM and SVR networks for use in surface-guided radiation therapy. Radiat Oncol 2021; 16:13. [PMID: 33446245 PMCID: PMC7807524 DOI: 10.1186/s13014-020-01729-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/06/2020] [Indexed: 02/08/2023] Open
Abstract
Background Surface-guided radiation therapy can be used to continuously monitor a patient’s surface motions during radiotherapy by a non-irradiating, noninvasive optical surface imaging technique. In this study, machine learning methods were applied to predict external respiratory motion signals and predict internal liver motion in this therapeutic context. Methods Seven groups of interrelated external/internal respiratory liver motion samples lasting from 5 to 6 min collected simultaneously were used as a dataset, Dv. Long short-term memory (LSTM) and support vector regression (SVR) networks were then used to establish external respiratory signal prediction models (LSTMpred/SVRpred) and external/internal respiratory motion correlation models (LSTMcorr/SVRcorr). These external prediction and external/internal correlation models were then combined into an integrated model. Finally, the LSTMcorr model was used to perform five groups of model updating experiments to confirm the necessity of continuously updating the external/internal correlation model. The root-mean-square error (RMSE), mean absolute error (MAE), and maximum absolute error (MAX_AE) were used to evaluate the performance of each model. Results The models established using the LSTM neural network performed better than those established using the SVR network in the tasks of predicting external respiratory signals for latency-compensation (RMSE < 0.5 mm at a latency of 450 ms) and predicting internal liver motion using external signals (RMSE < 0.6 mm). The prediction errors of the integrated model (RMSE ≤ 1.0 mm) were slightly higher than those of the external prediction and external/internal correlation models. The RMSE/MAE of the fifth model update was approximately ten times smaller than that of the first model update. Conclusions The LSTM networks outperform SVR networks at predicting external respiratory signals and internal liver motion because of LSTM’s strong ability to deal with time-dependencies. The LSTM-based integrated model performs well at predicting liver motion from external respiratory signals with system latencies of up to 450 ms. It is necessary to update the external/internal correlation model continuously.
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Affiliation(s)
- Guangyu Wang
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Zhibin Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Guangjun Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
| | - Guyu Dai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Qing Xiao
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Long Bai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yisong He
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yaxin Liu
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.,College of Physics, Sichuan University, Chengdu, 610065, China
| | - Sen Bai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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Yamauchi R, Mizuno N, Itazawa T, Kawamori J. The influence of respiratory motion on dose distribution in accelerated partial breast irradiation using volumetric modulated arc therapy. Phys Med 2020; 80:23-33. [PMID: 33075732 DOI: 10.1016/j.ejmp.2020.09.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022] Open
Abstract
PURPOSE Accelerated partial breast irradiation (APBI) is alternative treatment option for patients with early stage breast cancer. The interplay effect on volumetric modulated arc therapy APBI (VMAT-APBI) has not been clarified. This study aimed to evaluate the feasibility of VMAT-APBI for patients with small breasts and investigate the amplitude of respiratory motion during VMAT-APBI delivery that significantly affects dose distribution. METHODS The VMAT-APBI plans were generated with 28.5 Gy in five fractions. We performed patient-specific quality assurance using Delta4 phantom under static conditions. We also measured point dose and dose distribution using the ionization chamber and radiochromic film under static and moving conditions of 2, 3 and 5 mm. We compared the measured and calculated point doses and dose distributions by dose difference and gamma passing rates. RESULTS A total of 20 plans were generated; the dose distributions were consistent with those of previous reports. For all measurements under static conditions, the measured and calculated point doses and dose distributions showed good agreement. The dose differences for chamber measurement were within 3%, regardless of moving conditions. The mean gamma passing rates with 3%/2 mm criteria in the film measurement under static conditions and with 2 mm, 3 mm, and 5 mm of amplitude were 95.0 ± 2.0%, 93.3 ± 3.3%, 92.1 ± 6.2% and 84.8 ± 7.8%, respectively. The difference between 5 mm amplitude and other conditions was statistically significant. CONCLUSIONS Respiratory management should be considered for the risk of unintended dose distribution if the respiratory amplitude is >5 mm.
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Affiliation(s)
- Ryohei Yamauchi
- Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan.
| | - Norifumi Mizuno
- Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan
| | - Tomoko Itazawa
- Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan
| | - Jiro Kawamori
- Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan
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Freislederer P, Kügele M, Öllers M, Swinnen A, Sauer TO, Bert C, Giantsoudi D, Corradini S, Batista V. Recent advanced in Surface Guided Radiation Therapy. Radiat Oncol 2020; 15:187. [PMID: 32736570 PMCID: PMC7393906 DOI: 10.1186/s13014-020-01629-w] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/21/2020] [Indexed: 01/27/2023] Open
Abstract
The growing acceptance and recognition of Surface Guided Radiation Therapy (SGRT) as a promising imaging technique has supported its recent spread in a large number of radiation oncology facilities. Although this technology is not new, many aspects of it have only recently been exploited. This review focuses on the latest SGRT developments, both in the field of general clinical applications and special techniques.SGRT has a wide range of applications, including patient positioning with real-time feedback, patient monitoring throughout the treatment fraction, and motion management (as beam-gating in free-breathing or deep-inspiration breath-hold). Special radiotherapy modalities such as accelerated partial breast irradiation, particle radiotherapy, and pediatrics are the most recent SGRT developments.The fact that SGRT is nowadays used at various body sites has resulted in the need to adapt SGRT workflows to each body site. Current SGRT applications range from traditional breast irradiation, to thoracic, abdominal, or pelvic tumor sites, and include intracranial localizations.Following the latest SGRT applications and their specifications/requirements, a stricter quality assurance program needs to be ensured. Recent publications highlight the need to adapt quality assurance to the radiotherapy equipment type, SGRT technology, anatomic treatment sites, and clinical workflows, which results in a complex and extensive set of tests.Moreover, this review gives an outlook on the leading research trends. In particular, the potential to use deformable surfaces as motion surrogates, to use SGRT to detect anatomical variations along the treatment course, and to help in the establishment of personalized patient treatment (optimized margins and motion management strategies) are increasingly important research topics. SGRT is also emerging in the field of patient safety and integrates measures to reduce common radiotherapeutic risk events (e.g. facial and treatment accessories recognition).This review covers the latest clinical practices of SGRT and provides an outlook on potential applications of this imaging technique. It is intended to provide guidance for new users during the implementation, while triggering experienced users to further explore SGRT applications.
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Affiliation(s)
- P. Freislederer
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - M. Kügele
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - M. Öllers
- Maastricht Radiation Oncology (MAASTRO), Maastricht, the Netherlands
| | - A. Swinnen
- Maastricht Radiation Oncology (MAASTRO), Maastricht, the Netherlands
| | - T.-O. Sauer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - C. Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - D. Giantsoudi
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - S. Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - V. Batista
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor diseases (NCT), Heidelberg, Germany
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