Objective:To investigate the current status of clinical practice of optical surface guided radiation therapy (SGRT) technology in China.Methods:A survey questionnaire was designed based on a similar investigation conducted by the European Society for Radiotherapy and Oncology in collaboration with the American Association of Physicists in Medicine on SGRT. The questionnaire covered aspects such as the installation, implementation, commissioning, quality assurance, clinical application, challenges, and cost considerations of SGRT systems. An online questionnaire was distributed to 49 institutions in China that have installed or are in the process of installing SGRT systems. Data were summarized and analyzed using Excel and SPSS 29 software.Results:Among the 49 institutions, 96% had at least one SGRT system. In terms of commissioning, quality assurance and implementation, it was mainly operated by physicists (94%) and technicians (82%), the cycle of test items for quality assurance was only achieved by the highest percentage of units with end-to-end test items for the annual inspection (50%). Eighty-six percent of the institutions used phantoms provided by suppliers, and 53% followed supplier recommendations or guidelines. For the installation of the first SGRT system, 37% of the institutions reported that initial staff training required more than 48 hours, while 73% found the training content easy to understand. Regarding the clinical application of SGRT technology, the majority of the institutions (53%) had used it for 1-3 years, with breast radiotherapy being the most commonly used treatment site. The primary scenario of SGRT application was intra-fraction motion monitoring / patient monitoring (69%). Furthermore, 47% of the institutions combined SGRT with open-face masks, and 71% used visual feedback devices for breath-hold or free-breathing gating. In terms of treatment thresholds, the median thresholds for monitoring and positioning were the same for breast, abdominopelvic (non- stereotactic body radiation therapy), and head-and-neck (non-brain stereotactic radiosurgery) treatments but varied for other sites.Conclusions:Although SGRT technology requires a relatively long initial training period, it is generally well accepted in terms of training and operation. Clinically, SGRT has been widely applied in breast radiotherapy, playing a crucial role in patient monitoring and intra-fraction motion management. However, most institutions have had limited clinical experience with the technology, highlighting the need for continuous technical supervision and improvement. The establishment of standardized protocols is necessary to ensure broader clinical adoption and long-term effectiveness.

Objective To compare the positioning errors and the motion of acromioclavicular joint in breast cancer patients with integrated cervicothoracic thermoplastic membrane and breast bracket fixation,and to provide reference for accurate irradiation of upper and lower clavicular region.Methods Sixty-three pa-tients with breast cancer who were treated in the radiotherapy center of the hospital from November 1,2021 to August 9,2023 were selected as the study objects,and were divided into the integrated cervicothoracic thermo-plastic membrane group(n=32)and breast bracket group(n=31)according to different positioning meth-ods.The translation errors of left and right direction(X),head and foot direction(Y)and ventral and dorsal direction(Z)and the rotation errors of sagittal plane(Rx),cross section(Ry)and coronal plane(Rz)of the two groups were analyzed,and the movement amplitude and three-dimensional displacement of acromioclavic-ular joint were measured respectively.Results Compared with the breast bracket group,X translation errors[(0.18±0.14)cm vs.(0.15±0.12)cm]and Z translation errors[(0.19±0.14)cm vs.(0.16±0.14)cm]of the cervicothoracic thermoplastic memberane group were greater,Z translation error[(0.21±0.17)cm vs.(0.22±0.21)cm]and Rx rotation error of cervical and sternoclavicular joints[(0.93±0.87)° vs.(1.08±0.92)°]were smaller,Rz rotation error[(1.00±0.94)° vs.(0.95±0.86)°]was greater,and the motion ΔX of acromioclavicular joint[(0.18±0.15)cm vs.(0.25±0.21)cm]was smaller,the difference was statistically significant(P＜0.05).Conclusion Integrated cervicothoracic thermoplastic membrane can be used as a solu-tion for prophylactic irradiation of breast cancer in the upper and lower clavicular region and for radiation leak-age in the presence of metastasis.

Objective:To investigate the effects of psychological state on the setup errors of radiotherapy for breast cancer patients.Methods:A prospective cohort study was conducted. A total of 193 breast cancer patients in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from October 2022 to May 2023 were selected. Radiotherapy was performed after fixation with an integrated multi-functional device for the head, chest and abdomen. Psychological status of patients was assessed by using 9-item health questionnaire (PHQ-9) and generalized anxiety disorder 7 self-rating scale (GAD-7) before first radiotherapy, the 10th radiotherapy and the last radiotherapy. Based on the results of the questionnaires, patients were divided into psychological problem (anxiety or depression) group and non-psychological problem group. The general data and setup errors of radiotherapy in both groups were compared.Results:All the 193 patients were female, with a median age of 47 years. There were 53 patients in psychological problem group and they underwent a total of 507 image-guided procedures, with setup errors [ M ( Q1, Q3)] of 0.18 (0.07, 0.33), 0.20 (0.10, 0.33) and 0.19 (0.09, 0.30) in the left-right (X), superior-inferior (Y), and anterior-posterior (Z) directions, respectively; the remaining 140 patients in non-psychological problem group underwent 1 240 image-guided procedures, with setup errors [ M ( Q1, Q3)]of 0.17 (0.08, 0.30), 0.20 (0.10, 0.30) and 0.18 (0.09, 0.28) in the X, Y, and Z directions, respectively, and the differences were statistically significant ( Z values were -3.78, -2.00; P < 0.001, P = 0.046). Conclusions:Anxiety and depression have an influence on the setup errors of radiotherapy in patients with breast cancer. In the processs of radiotherapy for breast cancer, it is important to pay attention to the psychological status of patients.

Objective To investigate the setup error in patients with spinal bone metastasis who underwent radiotherapy under the guidance of kilovoltage cone-beam CT (KV-CBCT). Methods A total of 118 patients with spinal metastasis who underwent radiotherapy, including 17 cases of cervical spine, 62 cases of thoracic spine, and 39 cases of lumbar spine, were collected. KV-CBCT scans were performed using the linear accelerators from Elekta and Varian’s EDGE system. CBCT images were registered with reference CT images in the bone window mode. A total of 973 data were collected, and 3D linear errors were recorded. Results The patients with spinal bone metastasis were grouped by site, height, weight, and BMI. The P value of the patients grouped only by site was P<0.05, which was statistically significant. Conclusion When grouped by site in the 3D direction, the positioning effect of cervical spine is better than that of thoracic and lumbar spine. The positioning effect of the thoracic spine is better in the head and foot direction but worse in the left and right direction compared with that of the lumbar spine. Instead of extending or narrowing the margin according to the BMI of patients with spinal metastasis, the margin must be changed according to the site of spinal bone metastasis.

Objective:To investigate the effects of psychological state on the setup errors of radiotherapy for breast cancer patients.Methods:A prospective cohort study was conducted. A total of 193 breast cancer patients in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from October 2022 to May 2023 were selected. Radiotherapy was performed after fixation with an integrated multi-functional device for the head, chest and abdomen. Psychological status of patients was assessed by using 9-item health questionnaire (PHQ-9) and generalized anxiety disorder 7 self-rating scale (GAD-7) before first radiotherapy, the 10th radiotherapy and the last radiotherapy. Based on the results of the questionnaires, patients were divided into psychological problem (anxiety or depression) group and non-psychological problem group. The general data and setup errors of radiotherapy in both groups were compared.Results:All the 193 patients were female, with a median age of 47 years. There were 53 patients in psychological problem group and they underwent a total of 507 image-guided procedures, with setup errors [ M ( Q1, Q3)] of 0.18 (0.07, 0.33), 0.20 (0.10, 0.33) and 0.19 (0.09, 0.30) in the left-right (X), superior-inferior (Y), and anterior-posterior (Z) directions, respectively; the remaining 140 patients in non-psychological problem group underwent 1 240 image-guided procedures, with setup errors [ M ( Q1, Q3)]of 0.17 (0.08, 0.30), 0.20 (0.10, 0.30) and 0.18 (0.09, 0.28) in the X, Y, and Z directions, respectively, and the differences were statistically significant ( Z values were -3.78, -2.00; P < 0.001, P = 0.046). Conclusions:Anxiety and depression have an influence on the setup errors of radiotherapy in patients with breast cancer. In the processs of radiotherapy for breast cancer, it is important to pay attention to the psychological status of patients.

Objective:To investigate the current status of clinical practice of optical surface guided radiation therapy (SGRT) technology in China.Methods:A survey questionnaire was designed based on a similar investigation conducted by the European Society for Radiotherapy and Oncology in collaboration with the American Association of Physicists in Medicine on SGRT. The questionnaire covered aspects such as the installation, implementation, commissioning, quality assurance, clinical application, challenges, and cost considerations of SGRT systems. An online questionnaire was distributed to 49 institutions in China that have installed or are in the process of installing SGRT systems. Data were summarized and analyzed using Excel and SPSS 29 software.Results:Among the 49 institutions, 96% had at least one SGRT system. In terms of commissioning, quality assurance and implementation, it was mainly operated by physicists (94%) and technicians (82%), the cycle of test items for quality assurance was only achieved by the highest percentage of units with end-to-end test items for the annual inspection (50%). Eighty-six percent of the institutions used phantoms provided by suppliers, and 53% followed supplier recommendations or guidelines. For the installation of the first SGRT system, 37% of the institutions reported that initial staff training required more than 48 hours, while 73% found the training content easy to understand. Regarding the clinical application of SGRT technology, the majority of the institutions (53%) had used it for 1-3 years, with breast radiotherapy being the most commonly used treatment site. The primary scenario of SGRT application was intra-fraction motion monitoring / patient monitoring (69%). Furthermore, 47% of the institutions combined SGRT with open-face masks, and 71% used visual feedback devices for breath-hold or free-breathing gating. In terms of treatment thresholds, the median thresholds for monitoring and positioning were the same for breast, abdominopelvic (non- stereotactic body radiation therapy), and head-and-neck (non-brain stereotactic radiosurgery) treatments but varied for other sites.Conclusions:Although SGRT technology requires a relatively long initial training period, it is generally well accepted in terms of training and operation. Clinically, SGRT has been widely applied in breast radiotherapy, playing a crucial role in patient monitoring and intra-fraction motion management. However, most institutions have had limited clinical experience with the technology, highlighting the need for continuous technical supervision and improvement. The establishment of standardized protocols is necessary to ensure broader clinical adoption and long-term effectiveness.

Objective:To analyze the time needed for active breathing coordinator (ABC) coaching in tumor patients, and to explore the influencing factors of coaching time.Methods:A retrospective study was conducted on 93 patients who received ABC treatment led by the same staff at the Cancer Hospital of Chinese Academy of Medical Sciences from September 2019 to April 2021. The effects of education level, body mass index (BMI), age, gender and disease type on the couching time were analyzed. The coaching time was expressed as Mean ± SD. Independent sample t-test or rank sum test was used for comparison between different groups. P<0.05 was considered statistically significant. Results:Statistical significance was observed in the effect of education level, BMI and age on coaching time. The coaching time in the higher education group was (9.74±3.80) min, significantly shorter than the (13.79±6.03) min ( P=0.001) of the primary education group and the (13.03±5.14) min ( P=0.021) of the middle education group. The couching time in the BMI<24 kg/m 2 group was (10.27±3.98) min, significantly shorter compared with (12.74±5.60) min ( P<0.001) in the BMI≥24 kg/m 2 group. The coaching time in the ≥60 years old group was (14.12±5.06) min, significantly longer than the (9.86±3.76) min ( P=0.002) of the ≤40 years old group and the (11.30±5.10) min ( P=0.021) of the 40-60 years old group. No significant differences were noted in the effect of gender, disease type and tumor staging on the coaching time. The coaching time in males and females was (13.54±5.89) and (10.94±4.61) min, respectively ( P=0.071). The coaching time of patients with breast cancer, lung cancer, liver cancer, mediastinal lymphoma and pancreatic cancer was (10.75±4.72), (15.30±5.57), (11.69±4.96), (9.86±3.61) and (12.15±0.07) min, respectively ( P=0.071). The coaching time of stageⅠ,Ⅱ,Ⅲ and Ⅳ patients was (10.35±4.37), (11.88±5.30), (9.52±2.51) and (14.32±5.27) min ( P=0.060). Conclusions:Patients with higher education level and BMI<24 kg/m 2 require less ABC coaching time. Patients aged≥60 years require longer coaching time. Gender, disease type and clinical stage exert no significant effect on the duration of coaching.

Objective:To investigate the feasibility of surface-guided hypo-fractionated radiotherapy for intracranial metastasis with open face mask immobilization.Methods:Nineteen patients treated with hypo- fractionated radiotherapy for intracranial metastasis in our hospital were included. Before the start of treatment, each patient underwent simulation with open face mask immobilization. During the treatment, cone-beam CT(CBCT)images were collected for verification each time. Laser-guided positioning was used for the first time in the treatment, and surface images were captured after six-dimensional position correction as the reference images for subsequent treatment. Subsequent treatment was randomly divided into laser-guided positioning group(LG, 85/F)and optical surface-guided positioning group(SG, 101/F). The six-dimensional error data of patients with two positioning methods were compared and expressed as mean ± standard deviation. Meanwhile, the correlation and consistency between the optical surface error data and the gold standard CBCT error data were compared in the laser-guided fraction. GraphPad Prism 6.0 software was used for data processing and mapping, and SPSS 21.software was used for mean analysis and normality test. Pearson correlation analysis was used to analyze the correlation, and Bland-Altman plot analysis was used to test the coincidence between two methods.Results:Compared with the laser-guided positioning, the 3D error of optical surface-guided positioning was reduced from(0.35±0.16)cm to(0.14±0.07)cm. The Pearson coefficient of correlation along all three directions was less than 0.01,R 2 was 0.91,0.70 and 0.78 on Lat, Lng and Vrt, and R 2 was 0.75,0.85 and 0.77 on Pitch, Roll and Rtn(all P<0.01), respectively. The measurement results of two methods were positively correlated. The Bland-Altman plot analysis showed that the 95% limits of agreement were within preset 3 mm tolerance([-0.29 cm, 0.19 cm], [-0.25 cm, 0.25 cm], [-0.27 cm, 0.19 cm]), and the 95% limits of agreement were within preset 3° tolerance(Pitch[-1.76°,1.76°], Roll[-1.54°,1.60°], ROT[-2.18°,1.69°]), indicating agreement between two methods. Conclusions:The optical surface-guided positioning can reduce the setup errors in the hypo-fractionated radiotherapy for intracranial metastasis with open face mask immobilization. The optical surface error and CBCT error have good correlation and agreement.

Objective:To compare the setup errors in the supraclavicular regions of two different postures (arms placed on each side of the body, namely the body side group; arms crossed and elbows placed above forehead, namely the uplifted group) using the chest and abdomen flat frame fixation device in lung and esophageal cancer.Methods:Clinical data of patients with stage Ⅰ to Ⅳ lung or esophageal cancer who received three-dimensional radiotherapy with chest and abdomen flat frame fixation device in our institution from November 2020 to April 2021 were retrospectively analyzed. The setup errors of two postures were compared.Results:A total of 56 patients were included, including 31 patients (55%) in the body side group and 25 patients (45%) in the uplifted group. A total of 424 CBCTs were performed in the whole group. The overall setup errors in the X, Y and Z directions were similar in both groups ( P>0.05). The setup errors of sternoclavicular joint in the X and RZ directions in the body side group were significantly smaller than those in the uplifted group [(0.163±0.120) cm vs. (0.209 ±0.152) cm, P=0.033; 0.715°±0.628° vs. 0.910°±0.753°, P=0.011]. The setup errors of acromioclavicular joint in the Y, Z and RZ directions in the body side group were significantly smaller than those in the uplifted group [(0.233±0.135) cm vs. (0.284±0.193) cm, P=0.033; (0.202±0.140) cm vs. (0.252±0.173) cm, P=0.005; 0.671°±0.639° vs. 0.885°±0.822°, P=0.023]. The margins of target volume for setup errors were smaller in the X (0.45 cm vs. 0.54 cm) and Y (0.54 cm vs. 0.65 cm) directions of the sternoclavicular joint, as well as in the Y (0.59 cm vs. 0.78 cm) and Z directions (0.53 cm vs. 0.72 cm) of the acromioclavicular joint in the body side group. Conclusions:For lung and esophageal cancer patients requiring supraclavicular irradiation, the body side group yields smaller setup errors and corresponding margins of target volume than the uplifted group. In clinical practice, it is necessary to take comprehensive consideration of the accuracy of radiotherapy and additional radiation of the limbs to select appropriate posture.

Objective:To analyze the duration of each phase of Unity MR-linac in clinical application, aiming to provide reference for clinical optimization of the process time.Methods:Clinical data of 55 patients treated with Unity MR-linac were retrospectively analyzed. All patients were divided into the adapt to position (ATP) and adapt to shape (ATS) groups according to the planning method. The duration of each phase in the treatment process, the name and the time of each sequence, the number of beams, segments and total monitor units (MUs) were recorded and compared between two groups. In addition, the set-up time was counted according to different treatment sites. The time of each sequence and set-up time were expressed as the median M (Q 1, Q 3), and the number of beams, segments and total MUs of each plan were described as the mean±SD. Results:42 patients underwent ATP with a total of 305 treatment sessions: setup time was 3(2, 5) min, MR scanning time was 5(4, 7) min, registration time was 3(3, 4) min, adaptive planning time was 8(4, 12) min, beam on time was 8(6, 11) min, and the total time was 30(25, 36) min. 13 patients received ATS with a total of 65 treatment sessions: setup time was 2(2, 3) min, MR scanning time was 7(5, 8) min, registration time was 4(3, 5) min, time of delineation of target and organs at risk was 12(9, 16) min, adaptive planning time was 11(10, 14) min, beam on time was 10(9, 11) min and the total time was 55(49, 61) min. The set-up time according to treatment sites was 4(2, 4) min in the head and neck, 2(2, 4) min in the chest, and 3(2, 5) min in the abdomen. The number of fields, segments and total MUs during ATP were 8.1±1.7, 49.9±31.2, 846.75±363.44 in the head and neck, 8.0±2.0, 60.7±13.3, 790.21±279.00 in the chest, and 9.7±2.0, 81.2±22.3, 2007.32±1053.81 in the abdomen, respectively. The number of fields, segments and total MUs during ATS in head and neck of one case were 13, 39, 993.07, and 9.5±1.5, 65.5±6.3, 2763.26±835.41 in the abdomen.Conclusions:MR-guided radiotherapy yields huge potential in clinical application. However, there is still much room for the improvement of shortening the process duration.