Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective:To investigate the influence of ultrasonic monitoring of bladder filling levels on setup errors before fractionated radiotherapy for cervical cancer patients through a comparative analysis, and its effectiveness in improving clinical target volume (CTV) margins.Methods:A retrospective study was conducted on 1 284 error data of setup via cone beam CT (CBCT) and 6D setup error correction system from 172 cervical cancer patients treated in the Radiotherapy Department of Peking University Cancer Hospital from January 2019 to October 2023. These patients were classified into two groups: 87 (659 times of setup) with ultrasonic monitoring of bladder filling levels and 85 (625 times of setup) without ultrasonic monitoring. The setup errors, error distributions, and numbers of abnormal setups between the two groups were compared in the lateral (Lat), longitudinal (Lng), vertical (Vrt), pitch (Pitch), roll (Roll), and rotational (Rtn) dimensions. Moreover, the CTV to planning target volume(PTV) margin values in the three-dimensional direction were calculated for both groups to assess the clinical value of ultrasonic monitoring of bladder filling levels before fractionated radiotherapy.Results:Compared to the group without ultrasonic monitoring, the group with ultrasonic monitoring exhibited lower median values of setup errors in all six-dimensional directions and smaller upper and lower interquartile ranges ( Z = -10.86 to -6.34, P<0.05). The group with ultrasonic monitoring manifested more concentrated setup errors in various directions and statistically significantly reduced numbers of abnormal setups ( χ2=15.33, P<0.05). Moreover, CTV-PTV margins of the group with ultrasonic monitoring displayed reduced CTV-PTV margin values by 0.55, 1.52, and 1.26 mm in the Vrt, Lng, and Lat directions, respectively. Conclusions:Pre-radiotherapy ultrasonic monitoring of bladder filling levels in cervical cancer patients can significantly improve the repeatability of setup, thus notably reducing the incidence of abnormal setups. Theoretically, it can narrow the range from the CTV to the PTV, thereby minimizing radiation exposure to healthy tissues and ultimately enhancing radiotherapy precision for cervical cancer and reducing radiation damage.

Objective:To investigate the influence of ultrasonic monitoring of bladder filling levels on setup errors before fractionated radiotherapy for cervical cancer patients through a comparative analysis, and its effectiveness in improving clinical target volume (CTV) margins.Methods:A retrospective study was conducted on 1 284 error data of setup via cone beam CT (CBCT) and 6D setup error correction system from 172 cervical cancer patients treated in the Radiotherapy Department of Peking University Cancer Hospital from January 2019 to October 2023. These patients were classified into two groups: 87 (659 times of setup) with ultrasonic monitoring of bladder filling levels and 85 (625 times of setup) without ultrasonic monitoring. The setup errors, error distributions, and numbers of abnormal setups between the two groups were compared in the lateral (Lat), longitudinal (Lng), vertical (Vrt), pitch (Pitch), roll (Roll), and rotational (Rtn) dimensions. Moreover, the CTV to planning target volume(PTV) margin values in the three-dimensional direction were calculated for both groups to assess the clinical value of ultrasonic monitoring of bladder filling levels before fractionated radiotherapy.Results:Compared to the group without ultrasonic monitoring, the group with ultrasonic monitoring exhibited lower median values of setup errors in all six-dimensional directions and smaller upper and lower interquartile ranges ( Z = -10.86 to -6.34, P<0.05). The group with ultrasonic monitoring manifested more concentrated setup errors in various directions and statistically significantly reduced numbers of abnormal setups ( χ2=15.33, P<0.05). Moreover, CTV-PTV margins of the group with ultrasonic monitoring displayed reduced CTV-PTV margin values by 0.55, 1.52, and 1.26 mm in the Vrt, Lng, and Lat directions, respectively. Conclusions:Pre-radiotherapy ultrasonic monitoring of bladder filling levels in cervical cancer patients can significantly improve the repeatability of setup, thus notably reducing the incidence of abnormal setups. Theoretically, it can narrow the range from the CTV to the PTV, thereby minimizing radiation exposure to healthy tissues and ultimately enhancing radiotherapy precision for cervical cancer and reducing radiation damage.

Objective:To propose a markless patient setup workflow based on the optical surface monitoring system (AlignRT) and open-face mask immobilization for whole-course head tumor radiotherapy, assess the setup time and repositioning frequency of the proposed workflow, and conduct a comparative analysis of the differences, correlation, and consistency of the setup errors of the AlignRT and cone beam CT (CBCT) systems.Methods:A retrospective analysis was conducted for the data on the errors of 132 fractionated setup based on open-face mask immobilization of 33 head tumor patients. AlignRT-guided markless patient setup workflow was applied throughout the radiotherapy. Meanwhile, the body structures automatically generated by the treatment planning system were used as body references. The 6-degree-of-freedom (6DoF) setup errors (lateral, vertical, longitudinal, rotation, pitch, roll, and yaw directions), setup time, and repositioning frequency of the AlignRT and CBCT systems were recorded and analyzed. The Wilcoxon and Spearman analyses were used to statistically assess the differences and correlation of the setup errors of the two systems. Moreover, the Bland-Altman analysis was employed to evaluate the consistency of the two systems.Results:The 6DoF setup errors of CBCT were within the clinical tolerance (linear motions: -0.30 to 0.30 cm; rotational motions: -2.0° to 2.0°). The setup time and repositioning frequency of CBCT were (98 ± 31) s and 1.51% (2/132), respectively. There was no significant difference in setup errors between the two systems except those in x-axis ( Z = -3.11, P= 0.002), y-axis ( Z = -7.40, P<0.001), and Pitch ( Z= -4.48, P<0.001). There was a significant positive correlation between the setup errors along lateral ( rs = 0.47, P<0.001) and vertical ( rs = 0.29, P = 0.001) directions, rotation (Rtn; rs = 0.47, P<0.001), pitch (Pitch; rs = 0.28, P = 0.001) and roll (Roll; rs = 0.45, P<0.001) of the two systems. The 95% limits of agreement (95% LoA) of 6DoF setup errors were -0.12 to 0.09 cm, -0.07 to 0.17 cm, -0.19 to 0.20 cm, -1.0° to 0.9 °, -1.0° to 1.5°, and -0.9° to 1.0°, respectively. The 95% confidence interval (95% CI) of 95% LoA was -0.14 to 0.11 cm, -0.09 to 0.19 cm, -0.23 to 0.23 cm, -1.2° to 1.1°, -1.2° to 1.7°, and-1.0° to 1.1°, respectively, all of which were within the permissible error ranges. The 6DoF setup error difference of 3.41% (27/792< 5%) was beyond the 95% LoA. The maximum absolute differences of 6DoF setup errors within the 95% LoA were 0.12, 0.16, 0.19 cm, 0.9°, 1.5°, and 1.0°, respectively. Conclusions:The proposed markless setup workflow based on AlignRT combined with open-face mask immobilization for whole-course head tumor radiotherapy exhibits reasonable agreement and consistency with the patient setup using CBCT, with acceptable clinical efficiency. It can be applied to the first radiotherapy and the real-time monitoring of therapy to improve the safety and thus is of value in clinical applications.

Objective:To analyze and compare the radiation dose and image quality of kilo-voltage cone beam CT systems on different Varian accelerator platforms, providing data to support clinical decisions on selecting optimal protocols for image-guided radiotherapy based on cost-effective ratio (image quality / radiation dose).Methods:The radiation dose and image quality of various CBCT systems and scanning protocols on Varian Edge, Truebeam and ix (new and old) LINACs were obtained using a CT dose index (CTDI) phantom combined with a CT ionization chamber and a Catphan604 phantom, respectively. Figure of merit (FOM) was used to evaluate the cost-effective ratio of the image guidance schemes.Results:Considerable inter-system varieties of FOMs were observed, varying from 0.65 (Image Gently-full trajectory) to 48.46 (Image Gently-half trajectory). The inter-protocol varieties were also large, where the mean±SD was 22.14±13.47.Conclusions:Considering the explicit inter-system and inter-protocol varieties, it is clinically favorable to evaluate the image guidance schemes based on machine-specific measurement. For instance, parameters and equipment with low CTDI w can be beneficial for dose-sensitive patients. High CNR regimen favors patients with high image quality requirements. For ordinary patients, cost-effective ratio in terms of FOM can be very helpful to guide the decision-making of clinical image-guided radiotherapy.

Objective To explore the effect of Four Flavor Elimination Decoction on treatment of brain metastases.Methods Sixty patients with brain metastases,admitted to our hospital from January 2015 to January 2017,were selected.According to the willing of the patients,they were divided into observation group and control group (n=30).The patients from control group were given conventional medicines,and the patients from observation group were supplemented with Four Flavor Elimination Decoction on the basis of control group.The clinical efficacy of the two groups after treatment,and scores of Kamofsky performance status scale (KPS) and changes of T lymphocyte subsets and tumor markers before treatment and on 7th,14th,21th and 28th d of treatment were observed.Results The total effective rate of the observation group after treatment was 100％,which was significantly higher than that of the control group (50％,P＜0.05).KPS scores of the observation group were significantly higher than those of the control group on 21st and 28th d of treatment (P＜0.05).The levels of CD3+,CD4+ and CD8+ in the observation group were significantly higher than those of the control group after treatment (P＜0.05).The levels of carcino-embryonic antigen,carbohydrate antigen (CA)50 and CA125 in the observation group were significantly lower than those of the control group (P＜0.05).Conclusion Four Flavor Elimination Decoction is efficient in treatment of brain metastases,which can improve quality of life and immune indexes,and is worth of clinical application.

Objective To study the inhibitory effects ofberberine on human organic cation transporter (OCTs) including OCT1,OCT2,OCT3,OCTN1 and OCTN2.Methods Using animal cell transgenic method mediated by transporter Lipo 3000,the drug transporters over expression cell lines S2-OCT1,S2-OCT2,S2-OCT3,S2-OCTN1 and S2-OCTN2 were obtained by selective medium culture.The OCTs evaluation model was established by detecting the trans-membrane transport of radioactive substrate in vitro.Wild type (WT) cells were used as control group,activity of OCTs was verified by adding its inhibitor.The inhibition of berberine on the transporters was investigated in vitro.The IC50 of inhibitory effect of berberine on various drug transporters was also calculated.Result The transport activity of transporter cell lines was increased by more than 5 times compared to the WT cell line respectively,what's more,their transport activity decreased significantly by their corresponding inhibitor.The ICs0 of berberine to OCT1,OCT2,OCT3,OCTN1 and OCTN2 were respectively 7.63,6.80,2.25,4.66 and 210.34 μmol/L.Conclusion Berberine significant inhibition to OCT1,OCT2,OCT3,OCTN1 and OCTN2.The inhibition on OCT1,OCT2,OCT3,OCTN1 is stronger compared to OCTN2.

Objective To study the inhibition of berberine on organ anion transporters (OATs) and its bidirectional trans-membrane transport.Method The transgene cell lines of the organ anion transporters including OAT1,OAT2,OAT3,OAT4,OAT7,and URAT1 were constructed and selected by animal cell transgenic method mediated by transporter Lipo 3000.Wild type (WT) cells were used as control group,and activity of OATs was verified by adding their radiolabeled substrates and inhibitors.The inhibition of 100 μmol/L berberine on the transporters was investigated in vitro.The IC50 of berberine on URAT1 was also determined.The bidirectional transport of berberine was studied through the Caco-2 model.Result The results showed that 100 μmol/L berberine inhibited the activity of OAT1,OAT2,OAT3,OAT4,OAT7 and URAT1 to (70.48±4.23)％,(69.13±1.28)％,(72.12±3.28)％,(79.77±6.49)％,(69.51 ±5.99)％ and (38.4 ± 2.67)％ respectively,the IC50 of berberine to URAT 1 was 13.19 μmol/L,the Papp (A-B) of 50 μmol/L and 100 μmol/L berberine were separately 0.28 × 10-6 and 0.40 × 10-6 cm/s,and the effiux rates were separately 3.18 and 3.15.Conclusion Berberine shows a stronger inhibition to URAT1 compared to OAT1,OAT2,OAT3,OAT4 and OAT7.Berberine may be the substrate of some effiux transporters.This study provides theoretical basis for explaining the low bioavailability ofberberine and forecasting the possible drug-drug interaction.