1.Comparison of the efficacy and adverse events of radiotherapy timing and field extent after radical prostatectomy for prostate cancer
Mingyuan ZHU ; Ming LIU ; Lipin LIU ; Wenhui CAI ; Hui ZHU ; Gaofeng LI ; Qinhong WU ; Hailei LIN ; Dazhi CHEN ; Jingyi JIN ; Cui GAO ; Yonggang XU ; Qiuzi ZHONG
Chinese Journal of Radiation Oncology 2025;34(5):437-445
Objective:To compare the clinical efficacy and adverse events of different postoperative radiotherapy strategies (adjuvant radiotherapy versus salvage radiotherapy) and different irradiation fields (prostate bed versus prostate bed + pelvic radiation) in patients after radical prostatectomy for prostate cancer.Methods:This retrospective analysis included clinical data from 115 patients with localized or locally advanced prostate cancer who received intensity-modulated radiotherapy (IMRT) after radical prostatectomy at Beijing Hospital between March 2014 and September 2023. Among them, 40 patients received adjuvant radiotherapy, and 75 received salvage radiotherapy. And 74 patients received irradiation to both the prostate bed and pelvic (prostate bed + pelvic radiation group), while 41 patients received irradiation to the prostate bed alone (prostate bed irradiation group). Comparison was made between the adjuvant radiotherapy group and salvage radiotherapy group, as well as between prostate bed + pelvic radiation group and prostate bed irradiation group, in terms of overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRRFS), and the incidence of adverse events. Clinical characteristics were compared using the chi-square test. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors affecting survival were analyzed using Cox multivariate regression.Results:The median follow-up duration was 73.1 months. The 5-year OS, PFS and LRRFS rates for the entire cohort were 96.4%, 86.4%, and 93.2%, respectively. A total of 59 patients (51.3%) experienced grade 1-2 acute radiotherapy-related adverse events, while 43 patients (37.4%) experienced grade 1-2 late radiotherapy-related adverse events. No grade ≥ 3 late adverse events were observed. There were no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups ( P = 0.807, 0.996, and 0.976, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). The OS rate in the prostate bed + pelvic radiation group was significantly lower than that in the prostate bed irradiation group ( P = 0.036), while no significant differences were found in PFS or LRRFS ( P = 0.109 and 0.190, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). Multivariable analysis showed no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups, or between the prostate bed and prostate bed + pelvic irradiation groups ( P = 0.756, 0.341, 0.605; 0.938, 0.987, 0.605, respectively). Conclusions:In the era of modern IMRT, both adjuvant and salvage radiotherapy, as well as prostate bed and prostate bed + pelvic irradiation, demonstrate similar efficacy and safety profiles after radical prostatectomy for prostate cancer. Treatment outcomes were favorable, and adverse events were minimal.
2.Analysis of organ motion management and dose optimization in deep inspiration breath hold radiotherapy for breast cancer
Hailei LIN ; Hong GAO ; Xiangyan SHA ; Dan WANG ; Rui WANG ; Qinhong WU ; Qiuzi ZHONG ; Yonggang XU ; Gaofeng LI
Chinese Journal of Radiation Oncology 2025;34(12):1223-1229
Objective:To compare the treatment time stability, inter- and intra-fraction errors, and clinical target volume (CTV) to planning target volume (PTV) margin expansions under different gated window settings in deep inspiration breath hold (DIBH) radiotherapy for breast cancer, and to analyze the correlation between organ at risk (OAR) dose optimization and changes in lung volume.Methods:A retrospective analysis was conducted on 65 patients with left-sided breast cancer who received DIBH radiotherapy after modified radical mastectomy. CT simulation positioning was performed using 2 mm or 3 mm gated window for DIBH, followed by target delineation, treatment planning, and dose verification. During treatment, setup errors guided by cone beam CT (CBCT), intra-fraction monitoring errors, and treatment times were recorded. The coefficient of variation (CV) of treatment time was calculated for both gated window settings. Based on inter- and intra-fraction error distributions, the expansion distance of the CTV were determined using the van Herk formula. Dosimetric differences between DIBH and free-breathing (FB) plans for the left lung, heart, and left anterior descending coronary artery (LAD) were compared. Spearman correlation analysis was performed between the relative increase in left lung volume and the relative reduction in OAR dose. Paired t-tests were used for inter-group comparisons. Results:The mean CV of the 3 mm gated window group was 0.08±0.03, which was lower than that of the 2 mm group (0.10±0.04; t=-3.91, P<0.001). The setup errors of the 2 mm group in the X, Y, and Z directions were (1.27±1.03), (1.68±0.94), (1.90±1.25) mm, respectively-significantly smaller than those of the 3 mm group [(1.81±1.41), (2.07±1.69), (2.93±1.90) mm; t=-5.80, -2.33, -5.33; P<0.001,=0.014,<0.001). Setup errors for both groups were within the 25%-75% range and all below 5 mm. The intra-fraction deviations of the 2 mm group in the X, Y, and Z directions were (0.54±0.33), (0.79±0.44), (0.70±0.53) mm, respectively, significantly smaller than those of the 3 mm group [(0.62±0.43), (0.93±0.66), (0.87±0.67) mm; t=-3.87, -3.46, -2.71,all P<0.001). The mean intra-fraction errors of both groups were within 1 mm, with greater deviations in the Y and Z directions than those in the X direction. The CTV expansion margins for the 2 mm group in the X, Y, and Z directions were 4.21, 5.35, 5.99 mm, respectively, while those for the 3 mm group were 5.81, 6.89, 9.06 mm. Compared with FB, DIBH significantly reduced the doses to the left lung, heart, and LAD (all P<0.01). The increase in left lung volume was moderately negatively correlated with the reduction in left lung D mean ( r=-0.43, P=0.028), and highly negatively correlated with the dose reductions to the heart and LAD (both P<0.001). Conclusions:The variability in respiratory gated window settings can lead to differences in treatment time stability as well as inter- and intra-fraction errors, consequently affecting CTV-to-PTV margins. The DIBH technique demonstrates significant dosimetric benefits in reducing radiation exposure to the left lung, heart, and LAD. Volumetric expansion of the left lung is strongly and inversely correlated with the reduction in radiation dose to both the heart and LAD.
3.Comparison of the efficacy and adverse events of radiotherapy timing and field extent after radical prostatectomy for prostate cancer
Mingyuan ZHU ; Ming LIU ; Lipin LIU ; Wenhui CAI ; Hui ZHU ; Gaofeng LI ; Qinhong WU ; Hailei LIN ; Dazhi CHEN ; Jingyi JIN ; Cui GAO ; Yonggang XU ; Qiuzi ZHONG
Chinese Journal of Radiation Oncology 2025;34(5):437-445
Objective:To compare the clinical efficacy and adverse events of different postoperative radiotherapy strategies (adjuvant radiotherapy versus salvage radiotherapy) and different irradiation fields (prostate bed versus prostate bed + pelvic radiation) in patients after radical prostatectomy for prostate cancer.Methods:This retrospective analysis included clinical data from 115 patients with localized or locally advanced prostate cancer who received intensity-modulated radiotherapy (IMRT) after radical prostatectomy at Beijing Hospital between March 2014 and September 2023. Among them, 40 patients received adjuvant radiotherapy, and 75 received salvage radiotherapy. And 74 patients received irradiation to both the prostate bed and pelvic (prostate bed + pelvic radiation group), while 41 patients received irradiation to the prostate bed alone (prostate bed irradiation group). Comparison was made between the adjuvant radiotherapy group and salvage radiotherapy group, as well as between prostate bed + pelvic radiation group and prostate bed irradiation group, in terms of overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRRFS), and the incidence of adverse events. Clinical characteristics were compared using the chi-square test. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors affecting survival were analyzed using Cox multivariate regression.Results:The median follow-up duration was 73.1 months. The 5-year OS, PFS and LRRFS rates for the entire cohort were 96.4%, 86.4%, and 93.2%, respectively. A total of 59 patients (51.3%) experienced grade 1-2 acute radiotherapy-related adverse events, while 43 patients (37.4%) experienced grade 1-2 late radiotherapy-related adverse events. No grade ≥ 3 late adverse events were observed. There were no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups ( P = 0.807, 0.996, and 0.976, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). The OS rate in the prostate bed + pelvic radiation group was significantly lower than that in the prostate bed irradiation group ( P = 0.036), while no significant differences were found in PFS or LRRFS ( P = 0.109 and 0.190, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). Multivariable analysis showed no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups, or between the prostate bed and prostate bed + pelvic irradiation groups ( P = 0.756, 0.341, 0.605; 0.938, 0.987, 0.605, respectively). Conclusions:In the era of modern IMRT, both adjuvant and salvage radiotherapy, as well as prostate bed and prostate bed + pelvic irradiation, demonstrate similar efficacy and safety profiles after radical prostatectomy for prostate cancer. Treatment outcomes were favorable, and adverse events were minimal.
4.Analysis of organ motion management and dose optimization in deep inspiration breath hold radiotherapy for breast cancer
Hailei LIN ; Hong GAO ; Xiangyan SHA ; Dan WANG ; Rui WANG ; Qinhong WU ; Qiuzi ZHONG ; Yonggang XU ; Gaofeng LI
Chinese Journal of Radiation Oncology 2025;34(12):1223-1229
Objective:To compare the treatment time stability, inter- and intra-fraction errors, and clinical target volume (CTV) to planning target volume (PTV) margin expansions under different gated window settings in deep inspiration breath hold (DIBH) radiotherapy for breast cancer, and to analyze the correlation between organ at risk (OAR) dose optimization and changes in lung volume.Methods:A retrospective analysis was conducted on 65 patients with left-sided breast cancer who received DIBH radiotherapy after modified radical mastectomy. CT simulation positioning was performed using 2 mm or 3 mm gated window for DIBH, followed by target delineation, treatment planning, and dose verification. During treatment, setup errors guided by cone beam CT (CBCT), intra-fraction monitoring errors, and treatment times were recorded. The coefficient of variation (CV) of treatment time was calculated for both gated window settings. Based on inter- and intra-fraction error distributions, the expansion distance of the CTV were determined using the van Herk formula. Dosimetric differences between DIBH and free-breathing (FB) plans for the left lung, heart, and left anterior descending coronary artery (LAD) were compared. Spearman correlation analysis was performed between the relative increase in left lung volume and the relative reduction in OAR dose. Paired t-tests were used for inter-group comparisons. Results:The mean CV of the 3 mm gated window group was 0.08±0.03, which was lower than that of the 2 mm group (0.10±0.04; t=-3.91, P<0.001). The setup errors of the 2 mm group in the X, Y, and Z directions were (1.27±1.03), (1.68±0.94), (1.90±1.25) mm, respectively-significantly smaller than those of the 3 mm group [(1.81±1.41), (2.07±1.69), (2.93±1.90) mm; t=-5.80, -2.33, -5.33; P<0.001,=0.014,<0.001). Setup errors for both groups were within the 25%-75% range and all below 5 mm. The intra-fraction deviations of the 2 mm group in the X, Y, and Z directions were (0.54±0.33), (0.79±0.44), (0.70±0.53) mm, respectively, significantly smaller than those of the 3 mm group [(0.62±0.43), (0.93±0.66), (0.87±0.67) mm; t=-3.87, -3.46, -2.71,all P<0.001). The mean intra-fraction errors of both groups were within 1 mm, with greater deviations in the Y and Z directions than those in the X direction. The CTV expansion margins for the 2 mm group in the X, Y, and Z directions were 4.21, 5.35, 5.99 mm, respectively, while those for the 3 mm group were 5.81, 6.89, 9.06 mm. Compared with FB, DIBH significantly reduced the doses to the left lung, heart, and LAD (all P<0.01). The increase in left lung volume was moderately negatively correlated with the reduction in left lung D mean ( r=-0.43, P=0.028), and highly negatively correlated with the dose reductions to the heart and LAD (both P<0.001). Conclusions:The variability in respiratory gated window settings can lead to differences in treatment time stability as well as inter- and intra-fraction errors, consequently affecting CTV-to-PTV margins. The DIBH technique demonstrates significant dosimetric benefits in reducing radiation exposure to the left lung, heart, and LAD. Volumetric expansion of the left lung is strongly and inversely correlated with the reduction in radiation dose to both the heart and LAD.
5.Improvement effect of velvet antler polypeptide in osteoporosis model rats and its effect on SIRT1/FOXO1 signaling pathway
Xueting CHI ; Xiaowei HUANG ; Fangyuan CHEN ; Gaofeng ZHOU ; Jinji WANG ; Guangfu LYU ; Zhe LIN ; Qing GONG
Journal of Jilin University(Medicine Edition) 2024;50(1):120-127
Objective:To discuss the protective effect of velvet antler peptide(VAP)in the osteoporosis(OP)model rats,and to clarify the possible mechanism.Methods:Sixty 12-week-old SD rats were randomly divided into control group,model group,positive drug group(treated with 1 mg·kg-1·d-1 of alendronate sodium by gavage),low dose of VAP group(treated with 100 mg·kg-1·d-1 VAP),medium dose of VAP group(treated with 200 mg·kg-1·d-1 VAP),and high dose of VAP group(treated with 300 mg·kg-1·d-1 VAP),and there were ten rats in each group.Except for control group,the rats in the other groups were injected with dexamethasone(2 mg·kg-1)to replicate the OP rat model,while the rats in control group were injected with the equivalent volume of saline twice a week for 11 consecutive weeks.Dual-energy X-ray absorptiometry was used to detect the bone mineral density(BMD)of femur tissue of the rats in various groups;enzyme-linked immunosorbent assay(ELISA)method was used to detect the levels of serum calcium(Ca2+),phosphate(P),osteoprotegerin(OPG),alkaline phosphatase(ALP),and osteocalcin(OCN)in serum of the rats in various groups;biochemical method was used to detect the malondialdehyde(MDA)level and superoxide dismutase(SOD)activity in serum of the rats in various groups;HE staining was used to observe the pathomorphology of bone tissue of the rats in various groups;Western blotting method was used to detect the expression levels of silent information regulator 1(SIRT1),catalase(CAT),Runt-related transcription factor 2(RUNX2),and forkhead box protein O1(FOXO1)proteins in bone tissue of the rats in various groups.Results:Compared with control group,the BMD of femoral tissue of the rats in model group was decreased(P<0.05);compared with model group,the BMD of femur tissue of the rats in positive drug group,medium dose of VAP group,and high dose of VAP group were increased(P<0.05 or P<0.01).Compared with control group,the levels of Ca2+,P,OPG,and SOD activities in serum of the rats in model group were decreased(P<0.05),and the levels of ALP,OCN,and MDA were increased(P<0.05);compared with model group,the level of OPG in serum of the rats in low dose of VAP group was significantly increased(P<0.05),the levels of Ca2+,P,OPG,and activities of SOD in serum of the rats in positive drug group,medium dose of VAP group,and high dose of VAP group were significantly increased(P<0.05 or P<0.01),and the levels of ALP,OCN,and MDA in serum of the rats in positive drug group and different doses of VAP groups were decreased(P<0.05 or P<0.01).The HE staining results showed that compared with control group,the rats in model group had fewer bone cells and disordered arrangements in the bone tissue,thinner bone trabeculae with large fractures,and an expanded marrow cavity;compared with model group,the rats in positive drug group,medium dose of VAP group,and high dose of VAP group had thicker bone trabeculae arranged more tightly.The Western blotting results showed that compared with control group,the expression levels of SIRT1,CAT,RUNX2,and FOXO1 proteins in bone tissue of the rats in model group were decreased(P<0.05);compared with model group,the expression levels of SIRT1,CAT,RUNX2,and FOXO1 proteins in bone tissue of the rats in positive drug group,medium dose of VAP group,and high dose of VAP group were significantly increased(P<0.05 or P<0.01).Conclusion:VAP has the protective effect against OP in the rats,and its mechanism may be related to mediating the antioxidant stress action through the SIRT1/FOXO1 signaling pathway.
6.The application effect of preoperative autologous blood localization method in laparoscopic resection of gastric stromal tumors in unfavorable areas of the stomach
Qiyi LIN ; Liling CHEN ; Longqin LI ; Huaishuai WANG ; Yixiang ZHUANG ; Yinlin LI ; Zhicong CAI ; Jianpeng PAN ; Jianpeng CHEN ; Tao GUO ; Gaofeng LIN ; Guoxi XU
Journal of Chinese Physician 2024;26(8):1137-1139
Objective:To explore the application effect of preoperative autologous blood localization method in laparoscopic resection of gastric stromal tumors in unfavorable areas of the stomach.Methods:A retrospective analysis was conducted on the case data of 40 patients with gastric stromal tumors in unfavorable locations admitted to Jinjiang Hospital from January 2019 to December 2022. The patients were divided into a control group (intraoperative endoscopic localization method) and an autologous blood localization group according to different intraoperative lesion localization methods, with 20 cases in each group. The surgical time, intraoperative blood loss, hospitalization time, postoperative exhaust time, and adverse reactions were compared between the two groups.Results:The surgery time of the autologous blood localization group was shorter than that of the control group [(92.30±8.80)min vs (108.20±14.87)min, P<0.05]. There was no statistically significant difference in intraoperative bleeding, hospitalization time, and postoperative exhaust time between the two groups (all P>0.05). Two groups of patients did not show an increase in inflammatory indicators such as white blood cells and C-reactive protein on the day after surgery. Both groups of patients did not experience adverse reactions such as fever, abdominal pain, or postoperative complications. Conclusions:The autologous blood injection localization method provides a safe, simple, and effective method for preoperative localization of gastric stromal tumors in unfavorable areas of the stomach under laparoscopy, and is worthy of clinical promotion and use.
7.Comparison of the efficacy of Billroth Ⅱ+ Braun anastomosis and simple Billroth Ⅱ anastomosis in digestive tract reconstruction after laparoscopic distal gastric cancer radical resection
Huaishuai WANG ; Zhicong CAI ; Gaofeng LIN ; Guoxi XU ; Yixiang ZHUANG ; Yinlin LI ; Qiyi LIN ; Zaiyuan YE
Journal of Chinese Physician 2023;25(10):1464-1467
Objective:To compare the clinical efficacy and quality of life of patients between Billroth Ⅱ+ Braun anastomosis and simple Billroth Ⅱ anastomosis in digestive tract reconstruction after laparoscopic distal gastric cancer radical resection.Methods:A retrospective analysis was performed on clinical data of 68 patients who underwent laparoscopic distal gastric cancer radical resection in Jinjiang Municipal Hospital from January 2019 to January 2022. Forty patients who underwent Billroth Ⅱ+ Braun anastomosis were included in the observation group, and 28 patients who underwent simple Billroth Ⅱ anastomosis were included in the control group. Perioperative indicators and postoperative indicators one year after surgery were collected to observe the safety and efficacy of patients after surgery.Results:There were no significant differences in operation time, intraoperative bleeding volume, postoperative exhaust time, time to remove gastric tube and drainage tube, and postoperative hospital stay between the two groups (all P>0.05). There were also no significant differences in postoperative complications between the two groups ( P>0.05). One year after surgery, the incidence of food retention and residual gastritis in the observation group were lower than those in the control group (all P<0.05), while there were no significant differences in the incidence of bile reflux and reflux esophagitis between the two groups (all P>0.05). One year after surgery, nutritional evaluation showed that the total protein decline and prognostic nutritional index (PNI) in the observation group were lower than those in the control group, with significant differences (all P<0.05). The incidence of bloating and reflux symptoms in the observation group one year after surgery was lower than that in the control group, with significant differences (all P<0.05). Conclusions:Billroth Ⅱ+ Braun anastomosis is a safe method for digestive tract reconstruction after laparoscopic distal gastric cancer resection, which can improve patients′ quality of life after surgery.
8.Research progress and safety of immune checkpoint inhibitors in the treatment of gastrointestinal neoplasms
Yixiang ZHUANG ; Gaofeng LIN ; Guoxi XU ; Huaishuai WANG ; Zhicong CAI ; Yinlin LI ; Qiyi LIN ; Weibo LIU
Journal of Chinese Physician 2022;24(3):338-340,345
Gastrointestinal neoplasms is the most common digestive tract neoplasms, and its incidence rate is increasing year by year. Compared with other solid tumors, the application of immune checkpoint inhibitors in gastrointestinal neoplasms is still in the stage of continuous exploration. This paper intends to review the relevant research and latest progress of immune checkpoint inhibitors in advanced gastric cancer, mismatch repair function defect/microsatellite high instability and mismatch repair function integrity/microsatellite stability or microsatellite low instability, and further evaluate the effectiveness and safety of immunotherapy combined with relevant studies.
9.Efficacy comparison of albumin-bound paclitaxel and conventional paclitaxel combined with cisplatin and concurrent radiotherapy in treatment of locally advanced esophageal squamous cell carcinoma
Lin ZHU ; Gaofeng YUAN ; Xiao HU ; Shimeng LI ; Junxia HU ; Lei CAO ; Delin LIU ; Yimin LIU
Cancer Research and Clinic 2022;34(4):287-290
Objective:To explore the clinical efficacy and adverse reactions of albumin-bound paclitaxel (Nab-P) and conventional paclitaxel combined with cisplatin and concurrent radiotherapy for the treatment of patients with locally advanced esophageal squamous cell carcinoma.Methods:Forty-nine patients with locally advanced esophageal squamous cell carcinoma admitted to the First People's Hospital of Suqian from November 2016 to May 2020 were included. Of the 49 patients, 23 cases were treated with Nab-P combined with cisplatin and concurrent radiotherapy (NP group), 26 cases were treated with conventional paclitaxel combined with cisplatin and concurrent radiotherapy (TP group). All patients received 2 cycles of chemotherapy. The curative efficacy was evaluated one month after the end of radiotherapy, and the curative effect and adverse reactions of the two treatment regimens were compared.Results:The objective remission rate in NP group was 78.3% (18/23), and the disease control rate was 100.0% (23/23). The objective response rate in TP group was 61.5% (16/26), and the disease control rate was 92.3% (24/26). The objective response rate and disease control rate in NP group were higher than those in TP group, but the differences were not statistically significant (both P > 0.05). The common adverse reactions were mainly hair loss, loss of appetite, bone marrow suppression, radiation esophagitis, radiation pneumonia, malaise and myalgia. The incidence rate of grade 3-4 acute bone marrow suppression in NP group (8.7%, 2/23) was lower than that in TP group (38.5%, 10/26), and the difference was statistically significant ( χ2 = 4.35, P = 0.037). The incidence rate of myalgia in NP group (26.1%, 6/23) was lower than that in TP group (61.5%, 16/26), and the difference was statistically significant ( χ2 = 4.85, P = 0.028). Conclusions:Nab-P combined with cisplatin and concurrent radiotherapy has good efficacy in the treatment of patients with locally advanced esophageal squamous cell carcinoma, and the incidence rate of adverse reactions is lower than that of conventional paclitaxel combined with cisplatin and concurrent radiotherapy, so that the regimen is safe.
10.Comparison of different immobilization methods in breast cancer radiotherapy after breast-conserving surgery
Xuechen LUO ; Jialei YU ; Lin ZHU ; Xuenan LI ; Gaofeng LI ; Xia XIU ; Qiuzi ZHONG ; Yonggang XU
Chinese Journal of Radiological Medicine and Protection 2022;42(7):522-526
Objective:To compare and analyze the differences in the setup accuracy of different immobilization method in breast cancer radiotherapy after breast-conserving surgery.Methods:A retrospective study was conducted on 60 patients who received radiotherapy after breast-conserving surgery from January to August, 2021. These patients were divided into two groups. One group consisted of 30 cases who were immobilized using a modified body thermoplastic membrane combined with a multifunction body board during the breast cancer radiotherapy and was called the modified body thermoplastic membrane group. The other group comprised 30 cases immobilized using a vacuum cushion during breast cancer radiotherapy and was referred to as the vacuum cushion group. The setup errors, 3D vector errors, the proportion of errors of > 5 mm, and the dosimetric differences in the planning target volume (PTV) and the clinical target volume (CTV) before and after simulated treatment bed moving (including the PTV_ V100, PTV_ V95, and CTV_ V95 before simulated treatment bed moving and the PTV_ V100 S, PTV_ V95 S, and CTV_ V95 S after simulated treatment bed moving) were compared between two groups. Moreover, for the modified body thermoplastic membrane group, the changes in the average setup errors at different radiotherapy stages were also analyzed. Results:A total of 369 cone-beam CT scans were conducted for 60 patients, including 195 CT scans for the modified body thermoplastic membrane group and 174 CT scans for the vacuum cushion group. The setup errors in the x, y, and z directions (right-left, anterior-posterior, and superior-inferior, respectively) of the modified body thermoplastic membrane group were (2.59±1.98) mm, (2.38±2.04) mm, and (1.45±1.16) mm, respectively, while those of the other group were (2.24±1.63) mm, (2.78±2.17) mm, and (2.70±1.88) mm, respectively. The 3D vector errors of both groups were (4.32±2.28) mm and (5.13±2.14) mm, respectively. Therefore, the setup error in direction z and the 3D vector error of the modified body thermoplastic membrane group were less than those of the vacuum cushion group ( t = -7.77, -3.41, P<0.05). Moreover, the proportion of setup errors of > 5 mm in the x direction of the vacuum cushion group was lower than that of the modified body thermoplastic membrane group ( χ2 = 7.13, P<0.05), while such proportion in the z direction of the modified body thermoplastic membrane group was lower than that of the vacuum cushion group ( χ2= 5.90, P<0.05). After the simulated treatment bed moving, the PTV_ V100 S of the modified body thermoplastic membrane group was better than that of the vacuum cushion group ( t = 2.47, P < 0.05). Furthermore, for the modified body thermoplastic membrane group, the setup errors in the x direction in the first week were higher than those in the 2-3 weeks and 4-5 weeks ( P<0.05). Conclusions:The modified body thermoplastic membrane combined with a multifunction body board yield better immobilization effects than a vacuum cushion. However, it produces high setup errors in the x direction in the first week of the radiotherapy, to which special attention should be paid.

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