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 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 evaluate the application of visual feedback coaching method, which is embedded in an optical surface monitoring system, in deep inspiration breath holding during the radiotherapy in left breast cancer patients after breast-conserving surgery.Methods:Thirty patients with left breast cancer, who were scheduled to receive the whole breast radiotherapy after breast-conserving surgery, met the requirements of deep inspiration breath holding after respiratory coaching with the visual feedback coaching module in the optical surface monitoring system. Active breathing control equipment was used to control breath-holding state and CT simulation was performed. During treatment, optical surface monitoring system was used to guide radiotherapy. All patients were randomly divided into two groups. In group A ( n=15), visual feedback respiratory training method was utilized and not employed in group B ( n=15). In group A, the visual feedback coaching bar of the optical surface monitoring system was implemented, while audio interactive method was employed to guide patients to hold their breath. Real-time data of optical body surface monitoring were used to compare the interfraction reproducibility and intrafraction stability of breath holding fraction between two groups. Besides, the number of breath holding and treatment time per fraction were also compared. GraphPad prism 6.0 software was used for data processing and mapping, and SPSS 21.0 software was used for analyzing mean value and normality testing. Results:Compared with the control group, the reproducibility in the experiment group was reduced from 1.5 mm to 0.7 mm, the stability was reduced from 1.1 mm to 0.8 mm, the mean number of breath holding required per fraction was decreased from 4.6 to 2.4, the mean beam-on time per fraction from 336 s to 235 s, and the treatment time per fraction was shortened from 847 s to 602 s (all P<0.05), respectively. Conclusions:The application of visual feedback coaching method can improve the reproducibility and stability of breath holding during radiotherapy for left breast cancer, and it can also effectively reduce the number of breath holding and shorten the treatment time per fraction.

Objective:To summarize the experience of ELEKTA Unity MR-linac in clinical application in our hospital and analyze the positioning accuracy, process time and other related issues.Methods:A total of 14 patients enrolled in the Unity MR-Linac study were reviewed. All treatment time (including positioning, scanning, replanning, and beam discharge) and setup errors in 3directions were statistically analyzed. 11 patients with conventional accelerators using the multifunctional immobilization system (MIS) were randomly selected to make statistical analysis of the setup errors, and the differences between the Unity group and the conventional accelerators using the MIS were compared using t-test. Results:In the Unity group, the setup errors in X, Y and Z directions were (-0.15±0.30) cm, (0.02±0.57) cm and (-0.10±0.28) cm, respectively. The average treatment time was 36.87minutes. The average positioning time was 5.40minutes. The mean scan time was 7.48minutes, the mean adaptive plan time was 7.46minutes, and the mean beam time was 9.48minutes. In the conventional accelerator group, the setup errors were (0.05±0.25) cm, (-0.01±0.25) cm and (-0.03±0.23) cm, respectively. The results of the setup errors of patients fixed with MIS showed that there were significant differences in the left and right directions ( P<0.001), while there were no significant differences in the Y and Z directions ( P=0.061 and 0.374) between two groups. Conclusions:Except in the X direction, there is no significant difference in setup errors between the Unity and conventional accelerator groups in the condition of laser-free system. Under smooth circumstances, the treatment time by using ATP (adapt to position) workflow will also be within the range of tolerance of the patients. Magnetic-guided radiotherapy has a promising application prospect, whereas the procedure needs to be optimized.

Objective:To investigate the setup errors of postoperative radiotherapy immobilized with integrated cervicothoracic board (mask) system in breast cancer patients.Methods:Thirty-two breast cancer patients treated with postoperative radiotherapy immobilized with integrated cervicothoracic board (mask) system were prospectively recruited in this study. Breast/chest wall (cw) and supra/infraclavicular nodal region (sc) were irradiated with intensity-modulated radiotherapy. CBCT location verification in radiotherapy and target areas of the breast/chest wall and upper and lower collarbone were carried out, respectively. The consistency between setup errors and the position of the upper and lower target areas of 239 CBCT images was analyzed.Results:The translational setup errors of the breast/chest wall in the X-cw (left-right), Y-cw (superior-inferior), Z-cw (anterior-posterior) directions were (1.84±2.36) mm, (1.99±2.48) mm, and (1.75±1.86) mm, respectively. The translational setup errors of the supra/infraclavicular nodal region in the X-sc (left-right), Y-sc (superior-inferior), Z-sc (anterior-posterior) directions were (1.98±2.44) mm, (1.98±2.48) mm, and (1.71±1.79) mm, respectively. The differences of translational setup errors between the breast/chest wall and supra/infraclavicular nodal region in the X, Y, Z directions were (0.38±0.66) mm, (0.07±0.41) mm, and (0.45±0.92) mm, respectively. Conclusion:For the breast cancer patients treated with postoperative radiotherapy covering breast/chest wall and supra/infraclavicular nodal region, the integrated cervicothoracic board (mask) immobilization system provides good reproducibility and yields Sfew setup errors.

Objective:To evaluate the incidence of early cardiac injury in patients with left-sided breast cancer receiving hypofractionated radiotherapy after breast conserving surgery, and to investigate the correlation between cardiac injury and hypofractionated radiotherapy dose.Methods:We prospectively enrolled 103 breast cancer patients who received whole breast with or without regional nodal irradiation after breast conserving surgery using either deep inspiration breath-hold (DIBH) or free breathing (FB) radiotherapy technique. Cardiac examinations that included N-terminal pro-B-type natriuretic peptide (NT-proBNP), electrocardiogram, and myocardial perfusion imaging were performed routinely before and after radiotherapy. The effects of heart dose, systemic therapy and individual factors (Framingham score) on the incidence of cardiac events were analyzed.Results:The median age was 48 years. The mean dose (Dmean) of the heart, left anterior descending coronary artery (LAD), left ventricular (LV), and right ventricular (RV) were 4.0, 16.9, 6.3, and 4.4 Gy, respectively. With a median follow-up of 13.4 months, no patient had clinical cardiac abnormalities. The incidence rates of subclinical cardiac events at 1- 6- and 12-month were 23.5%, 31.6%, and 41.3%, respectively. The DIBH group had a lower mean dose, maximum dose, and V5-V40 in the heart, LAD, LV, and RV than the FB group ( P<0.001). Univariate analysis showed an increased incidence of subclinical cardiac events with heart Dmean >4 Gy, LAD V40 > 20%, LV Dmean >6 Gy, RV Dmean >7 Gy, or cumulative doses of anthracycline or taxane > 300 mg/m 2 (All P<0.05). Anti-HER2 targeted therapy, endocrine therapy and Framingham score were not associated with the incidence of subclinical cardiac events (all P>0.05). Multivariate analysis demonstrated that Dmean of LV and RV were independently associated with the increased incidence of subclinical cardiac events. Conclusions:Early subclinical heart injury are found in patients with left-sided breast cancer after hypofractionated radiotherapy. The increased incidence of subclinical cardiac events after radiotherapy is positively associated with the cardiac radiation doses.

Objective:To evaluate the incidence of early cardiac injury in patients with left-sided breast cancer receiving hypofractionated radiotherapy after breast conserving surgery, and to investigate the correlation between cardiac injury and hypofractionated radiotherapy dose.Methods:We prospectively enrolled 103 breast cancer patients who received whole breast with or without regional nodal irradiation after breast conserving surgery using either deep inspiration breath-hold (DIBH) or free breathing (FB) radiotherapy technique. Cardiac examinations that included N-terminal pro-B-type natriuretic peptide (NT-proBNP), electrocardiogram, and myocardial perfusion imaging were performed routinely before and after radiotherapy. The effects of heart dose, systemic therapy and individual factors (Framingham score) on the incidence of cardiac events were analyzed.Results:The median age was 48 years. The mean dose (Dmean) of the heart, left anterior descending coronary artery (LAD), left ventricular (LV), and right ventricular (RV) were 4.0, 16.9, 6.3, and 4.4 Gy, respectively. With a median follow-up of 13.4 months, no patient had clinical cardiac abnormalities. The incidence rates of subclinical cardiac events at 1- 6- and 12-month were 23.5%, 31.6%, and 41.3%, respectively. The DIBH group had a lower mean dose, maximum dose, and V5-V40 in the heart, LAD, LV, and RV than the FB group ( P<0.001). Univariate analysis showed an increased incidence of subclinical cardiac events with heart Dmean >4 Gy, LAD V40 > 20%, LV Dmean >6 Gy, RV Dmean >7 Gy, or cumulative doses of anthracycline or taxane > 300 mg/m 2 (All P<0.05). Anti-HER2 targeted therapy, endocrine therapy and Framingham score were not associated with the incidence of subclinical cardiac events (all P>0.05). Multivariate analysis demonstrated that Dmean of LV and RV were independently associated with the increased incidence of subclinical cardiac events. Conclusions:Early subclinical heart injury are found in patients with left-sided breast cancer after hypofractionated radiotherapy. The increased incidence of subclinical cardiac events after radiotherapy is positively associated with the cardiac radiation doses.

Objective Evaluation the Fractionated Stereotactic Radiotherapy (FSRT) for the patients with small-cell lung cancer (SCLC) after the whole brain radiotherapy (WBRT) failure.Methods We retrospectively analyzed 35 patients with brain metastases from small-cell lung cancer treated with linear accelerator FSRT after the WBRT failure. Multivariate analysis was used to determine significant prognostic factor related to survival.ResultsThe following-up rate was 100％.The median following-up time was 11 months.The median over-all survival (OS) time was 10.3( 1 -30) months after FSRT.Controlled extra cranial disease was the only identified significant predictor of increased median OS time (χ2 =4.02,P =0.045 ).The median OS time from the diagnosis of brain metastasis was 22 (6 - 134 )months.14 patients died from brain metastasis,14 from extra-cranial progression,1 from leptomeningeal metastases,and 3 from other causes. Local control at 6 months and 12 months was 91％ and 76％,respectively.No significant late complications.New brain metastases outside of the treated area developed in 17％ of patients at a median time of 4(2 -20) months; all patients had received previous WBRT.ConclusionsFractionated stereotactic radiotherapy was safe and effective treatment for recurrent small-cell lung carcinoma brain metastases.

Objective To verify and assess diagnostic value of noninvasive diagnostic model of liver fibrosis in primary biliary cirrhosis (PBC) based on conventional laboratory markers.Methods Seventythree patients with PBC diagnosed by liver biopsy between January 2003 and June 2011 in Beijing Friendship Hospital,Capital Medical University were recruited in this study.Correlation analysis and logistic regression analysis between the conventional laboratory markers and histology stages were assessed.A liver fibrosis diagnostic model was established based upon aforementioned biomarkers and verified by its sensitivity and specificity for predicting the liver fibrosis.Results The predictive model ( H index) consisting of five conventional laboratory markers,i.e.,platelet count,serum cholinesterase,albumin,HDL-C and prothrombin time activity,could predict advanced fibrosis ( stages Ⅲ-Ⅳ ) with an AUCROC of 0.861.The sensitivity of predicting the absence of advanced fibrosis using H index ＜ - 2.20 was 96.6％ and the specificity of predicting the presence of advanced fibrosis using H index ＞ 0.41 was 93.2％.Conclusion The established noninvasive diagnostic model consisting of five laboratory markers could accurately distinguish pathological changes of early stage PBC ( stages Ⅰ - Ⅱ ) from advanced stage PBC ( stages Ⅲ-Ⅳ).