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 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 evaluate the effects of the multiple factors especially image geometric accuracy of the imaging system on the segmentations of target areas and organs-at-risk.Methods The study used phantoms to test the imaging performance of the 1.5T magnetic resonance(MR)linear accelerator system,including the assessments of MR image geometric distortion and the segmentation errors caused by factors such as image geometric distortion.Model 604-GS large field MR image distortion phantom was used to explore the geometric distortion of the MR images for MR-guided radiotherapy;and CIRS Model 008z upper abdominal phantom was used to analyze the segmentation errors of target areas and organs-at-risk.Results The average geometric distortion and maximum distortion of 3D T1WI-FFE images vs 3D T2WI-TSE images were 0.54 mm vs 0.53 mm and 1.96 mm vs 1.68 mm,respectively;and the control points of the large distortions were distributed at the edges of the phantom,which was consistent with the MR imaging characteristics previously reported.Compared with CT-based segmentation contour,the MDA was 1.17 mm and DSC was 0.91 for 3D T1WI-FFE,while MDA was 0.86 mm and DSC was 0.94 for 3D T2WI-TSE.Conclusion The study quantitatively assesses the geometric accuracy of the imaging system for MR-guided radiotherapy.The phantom-based contour analysis reveals that with CT image as gold standard,the segmentation error in MRI images meets the clinical requirements,and that 3D T2WI-TSE image is advantageous over 3D T1WI-FFE image in segmentation accuracy.

Background::Magnetic resonance (MR)-guided ultra-hypofractionated radiotherapy with whole-pelvic irradiation (UHF-WPRT) is a novel approach to radiotherapy for patients with high-risk (HR) and very high-risk (VHR) prostate cancer (PCa). However, the inherent complexity of adaptive UHF-WPRT might inevitably result in longer on-couch time. We aimed to estimate the delivered dose, study the feasibility and safety of adaptive UHF-WPRT on a 1.5-Tesla MR-Linac.Methods::Ten patients with clinical stage T3a-4N0-1M0-1c PCa, who consecutively received UHF-WPRT, were enrolled prospectively. The contours of the target and organ-at-risks on the position verification-MR (PV-MR), beam-on 3D-MR(Bn-MR), and post-MR (after radiotherapy delivery) were derived from the pre-MR data by deformable image registration. The physician then manually adjusted them, and dose recalculation was performed accordingly. GraphPad Prism 9 (GraphPad Prism Software Inc.) was utilized for conducting statistical analyses.Results::In total, we collected 188 MR scans (50 pre-MR, 50 PV-MR, 44 Bn-MR, and 44 post-MR scans). With median 59 min, the mean prostate clinical target volume (CTV)-V 100% was 98.59% ± 2.74%, and the mean pelvic CTVp-V 100% relative percentages of all scans was 99.60% ± 1.18%. The median V 29 Gy change in the rectal wall was -2% (-18% to 20%). With a median follow-up of 9 months, no patient had acute Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or more severe genitourinary (GU) or gastrointestinal (GI) toxicities (0%). Conclusion::UHF-RT to the prostate and the whole pelvis with concomitant boost to positive nodes using an Adapt-To-Shape (ATS) workflow was technically feasible for patients with HR and VHR PCa, presenting only mild GU and GI toxicities. The estimated target dose during the beam-on phase was clinically acceptable based on the 3D-MR–based dosimetry analysis.Clinical trial registration::Chinese Clinical Trial Registry ChiCTR2000033382.

Background::Magnetic resonance (MR)-guided ultra-hypofractionated radiotherapy with whole-pelvic irradiation (UHF-WPRT) is a novel approach to radiotherapy for patients with high-risk (HR) and very high-risk (VHR) prostate cancer (PCa). However, the inherent complexity of adaptive UHF-WPRT might inevitably result in longer on-couch time. We aimed to estimate the delivered dose, study the feasibility and safety of adaptive UHF-WPRT on a 1.5-Tesla MR-Linac.Methods::Ten patients with clinical stage T3a-4N0-1M0-1c PCa, who consecutively received UHF-WPRT, were enrolled prospectively. The contours of the target and organ-at-risks on the position verification-MR (PV-MR), beam-on 3D-MR(Bn-MR), and post-MR (after radiotherapy delivery) were derived from the pre-MR data by deformable image registration. The physician then manually adjusted them, and dose recalculation was performed accordingly. GraphPad Prism 9 (GraphPad Prism Software Inc.) was utilized for conducting statistical analyses.Results::In total, we collected 188 MR scans (50 pre-MR, 50 PV-MR, 44 Bn-MR, and 44 post-MR scans). With median 59 min, the mean prostate clinical target volume (CTV)-V 100% was 98.59% ± 2.74%, and the mean pelvic CTVp-V 100% relative percentages of all scans was 99.60% ± 1.18%. The median V 29 Gy change in the rectal wall was -2% (-18% to 20%). With a median follow-up of 9 months, no patient had acute Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or more severe genitourinary (GU) or gastrointestinal (GI) toxicities (0%). Conclusion::UHF-RT to the prostate and the whole pelvis with concomitant boost to positive nodes using an Adapt-To-Shape (ATS) workflow was technically feasible for patients with HR and VHR PCa, presenting only mild GU and GI toxicities. The estimated target dose during the beam-on phase was clinically acceptable based on the 3D-MR–based dosimetry analysis.Clinical trial registration::Chinese Clinical Trial Registry ChiCTR2000033382.

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 workflow, efficacy and safety of MR-Linac in liver malignancies.Methods:Clinical data of 15 patients with hepatocellular carcinomas (HCC) or liver metastases treated with MR-Linac between November 2019 and July 2021 were retrospectively analyzed. The workflow of MR-Linac was investigated and image identification rate was analyzed. Patients were followed up for response and toxicity assessment.Results:Fifteen patients (6 HCC, 8 liver metastases from colorectal cancer, 1 liver metastasis from breast cancer) were enrolled. A total of 21 lesions were treated, consisting of 10 patients with single lesion, 4 patients with double lesions and 1 patient with triple lesions. The median tumor size was 2.4 cm (0.8-9.8 cm). The identification rate for gross tumor volume (GTV) in MR-Linac was 13/15. Although GTV of two patients were unclearly displayed in MR-Linac images, the presence of adjacent blood vessel and bile duct assisted the precise registration. All the patients were treated with stereotactic body radiation therapy (SBRT). For HCC, the median fraction dose for GTV or planning gross tumor volume (PGTV) was 6 Gy (5-10 Gy) and the median number of fractions was 9(5-10). The median total dose was 52 Gy (50-54 Gy) and the median equivalent dose in 2 Gy fraction (EQD 2Gy) at α/ β= 10 was 72 Gy (62.5-83.3 Gy). For liver metastases, the median fraction dose for GTV or PGTV was 5 Gy (5-10 Gy) and the median number of fractions was 10(5-10). The median total dose was 50 Gy (40-50 Gy) and the median EQD 2Gy at α/ β=5 was 71.4 Gy (71.4-107.1 Gy). At 1 month after SBRT, the in-field objective response rate (ORR) was 8/13 and the disease control rate was 13/13. At 3-6 months after SBRT, the in-filed ORR was increased to 6/6. During the median follow-up of 4.0 months (0.3-11.6), 4-month local progression-free survival, progression-free survival and overall survival were 15/15, 11/15 and 15/15, respectively. Toxicities were mild and no grade 3 or higher toxicities were observed. Conclusions:MR-Linac provides a platform with high identification rates of liver lesions. Besides, the presence of adjacent blood vessel and bile duct also assists the precise registration. It is especially suitable for liver malignancies with promising local control and well tolerance.

Objective:To describe a prospective study of pre-operative tumor-bed boost performed at the 1.5 T MR-Linac in combination with adjuvant whole breast irradiation, and a first case, with an accentuation on clinical feasibility and safety.Methods:A phase II, single arm study recruiting early stage patients follows a paradigm that first boosts the tumor bed and then undergoes breast conservative surgery in 2 weeks, and last irradiates the whole breast in 6 weeks. The primary endpoint is ≥ grade 2 acute breast toxicity. A 43 years old patient affected by a breast carcinoma, not special type of the right-sided lateral quadrant, staged cT 2N 0M 0, was planned and treated. The dose, 8 Gy for one time, was calculated by Monaco on CT simulation images. Both the air electron stream effect (ESE) and the electron return effect (ERE) at the presence of 1.5 T magnetic field were evaluated. During the pre-treatment evaluation, we carried out adaptation-to-position adjustment. Results:The normal organ dosimetry is within toleration. The Dmax to the skin, the chin and the right upper arm was 8.44 Gy, 28.5 cGy and 17.8 cGy, respectively. There was no increased toxicity from ERE and ESE, and the treatment was well tolerated without > grade 1 acute toxicity. The patient received breast conservative surgery on day 7 without delayed wound healing.Conclusions:This is the first case successfully treated within a clinical trial by pre-operative tumor-bed boost under 1.5 T MR-Linac in our institution. More participants are needed to validate and optimize the paradigm.

With aligned MR registration, the MR-Linac provides superior soft tissue resolution for prostate cancer. No fiducial markers or electromagnetic transponders insertion is needed to guarantee high-precision radiotherapy. The highly-recommended Adapt-To-Shape (ATS) workflow can resolve all the problems encountered during prostate cancer radiotherapy, including prostate volume changes and adjacent organs motion, both inter-fractionally and intra-fractionally. With all the above advantages, MR-Linac performs outstandingly than conventional linac in prostate cancer RT delivery, and probably helps us to reduce the CTV-PTV margin safely in the near future. Nevertheless, it is difficult to implement the ATS workflow in clinical practice. In this article, the standard ATS workflow for prostate cancer was summarized based on our own experience.

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.