Objective:To explore the effects of bladder volumes from CT simulation on bladder volume consistency and set-up errors during radiotherapy for prostate cancer, aiming to provide a reference for clinical practice.Methods:A retrospective analysis was conducted for of 66 prostate cancer patients treated with intensity-modulated radiation therapy in the Sun Yat-sen University Cancer Center from August 2015 to November 2020. They underwent CT scan or radiotherapy after voluntarily holding in urine. Cone beam computed tomography (CBCT) scans were performed for them to measure their set-up errors in left-right (L-R), superior-inferior (S-I), and anterior-posterior (A-P) directions before each treatment. The bladder contours of the patients were delineated on CT simulation images and CBCT images. Accordingly, bladder volumes were calculated. Based on the calculated bladder volumes derived from the CT simulation images, the patients were divided into three groups: 18 cases in the 200-300 ml group, 24 cases in the 300-400 ml group, and 24 cases in the >400 ml group. Finally, this study analyzed the effects of bladder volumes derived from CT simulation on set-up errors and the changes of CBCT-derived bladder volumes relative to planned volumes during radiotherapy.Results:The bladder volumes in the 200-300 ml, 300-400 ml, and >400 ml groups during radiotherapy were reduced by 15%, 26%, and 32%, respectively. The pairwise comparison indicates statistically significant differences in the changes of bladder volumes among the three groups ( Z=3.43, 7.97, 4.83, P<0.05). Regarding the three-dimensional set-up errors, there were statistically significant differences in S-I set-up errors among the three groups ( H=26.72, P<0.05), but there was no statistically significant difference in L-R and A-P set-up errors ( P>0.05) among these groups. The 200-300 ml, 300-400 ml, and >400 ml groups exhibited S-I set-up errors of 0.00 (-0.20, 0.20) cm, 0.00 (-0.20, 0.30) cm, and -0.10 (-0.30, 0.20) cm, respectively. Therefore, the >400 ml group displayed larger the S-I set-up errors than other two groups, with statistically significant differences ( Z=4.17, 4.66, P< 0.05), while there was no statistically significant differences in S-I set-up errors between other two groups ( P> 0.05). Conclusions:Controlling the bladder filling volumes at 200-300 ml in CT simulation is beneficial for maintaining bladder volume consistency and reducing set-up errors of patients during radiotherapy.

Objective:To investigate the clinical feasibility of the Unity radiotherapy system guided by magnetic resonance imaging.Methods:Twenty-four patients were enrolled and received a total of 384 fractions of treatment at Unity system. According to the treatment site, all patients were divided into head-neck, abdomen-thorax, pelvic, spine and limb groups. The patients were set-up without external laser. And then, the time required at different stages in online treatment process and the registration error of each fraction were separately calculated. The geometric deformations of MR images were weekly measured by using MR geometric deformation phantom. At last, the Arccheck was used to perform the dose verification of reference plan, online plan and offline plan.Results:The mean duration of radiotherapy in the five groups were 29.1, 27.6, 26.6, 25.6 and 32.0 min, respectively. The set-up errors in the left-right, superior-inferior and anterior-posterior direction in the five groups were: head-neck group (0.08±0.06 cm, 0.16±0.13 cm, 0.08±0.05 cm), abdomen-thorax group (0.23±0.18 cm, 0.50±0.47 cm, 0.12±0.1 cm), pelvic group (0.25±0.19 cm, 0.32±0.25 cm, 0.11±0.09 cm), spine group (0.46±0.38 cm, 0.26±0.26 cm, 0.13±0.07 cm) and limb group (0.33±0.30 cm, 0.34±0.23 cm, 0.08±0.06 cm), respectively. In the central region, the geometric deformation of MR was less than 0.3 mm, and that of the sphere with a diameter of 500 mm was less than 2.1 mm. The meanγ pass rate of the reference plan, online plan and offline plan were 97.92%, 97.84% and 94.58%, respectively.Conclusions:MR-guided radiotherapy has great potential for clinical application, whereas the process of Unity system is relatively complex. The synergy of different departments has a great impact on the treatment, which needs further optimization.

Objective:To standardize the naming of organ at risk (OAR) and target area during cervical cancer radiotherapy based on AAPM TG-263.Methods:After self-programming of Matlab software to implement the reading and resolution of radiotherapy structure files, the naming of each substructure was automatically output, recorded and restored. After naming all substructures, the structure names were classified by keywords. According to TG-263, a standard naming conversion table of OAR and target area was developed, and the classified structure names were standardized through procedures. Finally, the standardized named radiotherapy structure files were output and imported into the treatment planning system (TPS).Results:The radiation structure of 144 patients with cervical cancer was successfully transformed and displayed correctly in TPS. Before the transformation, the naming of OAR and target area lacked of uniform norms and standards, and the naming of the same structure significantly differed. After the transformation, 43 naming methods of OAR and 74 naming methods of the target area were unified into 20 and 8 naming methods, which were more convenient for staff understanding and communication.Conclusion:The standardization of cervical cancer radiotherapy structure naming can reduce the inconsistency of naming and provide reference for the standardized naming of pelvic tumors.

Objective:To evaluate the clinical efficacy of multi-disciplinary single center's CCCG-HB-2016 regimen in the treatment of hepatoblastoma (HB) in children.Methods:Clinical data of 36 HB patients treated with CCCG-HB-2016 program from Aug 2016 to March 2020 were analyzed.Results:These 36 patients included 20 boys and 16 girls. The serum AFP was all higher than 2 792 ng/ml,there was a correlation between AFP and tumor risk stratification ( H=14.973, P<0.05). Twenty eight cases (77.78%) were epithelial type and 8 cases (22.22%) were mixed epithelial mesenchymal type.All children were treated by tumor resection combined with chemotherapy, and there was a correlation between tumor risk stratification and surgical resection of liver lobe ( H=8.847, P<0.05). The probability of bone marrow suppression in the low-risk group was 58.33% (35/60),that in the intermediate-risk group was 73.49% (61/83) and in the high-risk group was 80.23% (69/86).All 36 cases were followed up to March 31, 2020,with an average follow-up of 21.9 months and the median survival was 22.5 months.The overall survival rate (OS) and event-free survival rate (EFS) were 97.2% and 83.3% respectively. Conclusions:The multidisciplinary CCCG-HB-2016 regimen was with a high success rate and along with a high incidence of bone marrow suppression.

Objective:To evaluate the preliminary clinical efficacy and safety of stereotactic body radiation therapy (SBRT) in combination with targeted therapy for metastatic renal cell carcinoma (mRCC).Methods:Clinical data of 58 patients with mRCC who were treated with SBRT in combination with targeted therapy in Sun Yat-sen University Cancer Center from June 2013 to December 2018 were retrospectively analyzed. Among them, 79.3% patients were classified as intermediate or high risk according to International Metastatic Renal Cell Carcinoma Database Consortium Criteria. The median biologically equivalent dose (BED) was 147 Gy (67 to 238 Gy).Results:Overall, 32, 13, 7, 5 and 1 patients received SBRT for 1, 2, 3, 4 and 6 metastatic sites (105 lesions) and 71.4% of them were bone lesions. Targeted therapy was continued during SBRT. With a median follow-up of 9.4 months (range 2.7 to 40.1 months), 18 patients died. The 1-year local control rate was 97.4%. The 1-year progression-free survival was 50.3%. The 1-and 2-year overall survival was 72% and 53%. Approximately 85% patients experienced pain relief after SBRT. Patients who achieved complete or partial response after SBRT obtained better overall survival than those with stable disease or disease progression (1-year overall survival: 83% vs. 48%, P=0.021). In the whole cohort, 6 cases developed Grade Ⅲ adverse events, 4 of which were Grade Ⅲ myelosuppression, 1 case of Grade Ⅲ neuropathy and 1 case of radiation-induced skin injury. Conclusion:Preliminary study reveals that combined use of targeted therapy and SBRT is an efficacious and safe treatment of advanced mRCC.

Objective To compare the positioning accuracy between personalized polyurethane foam with wing boards and negative pressure vacuum bag in radiotherapy for lung cancer using kilovoltage cone beam computed tomography(CBCT). Methods Thirty-nine patients with lung cancer who received chest radiotherapy in our hospital from 2015 to 2016 were enrolled as subjects. In those patients, 20 were immobilized by negative pressure vacuum bags(VB group)and the others by personalized polyurethane foam with wing boards(PF group).CBCT images were acquired weekly and registered with planning CT images. Setup errors in the left-right, superior-inferior, and anterior-posterior directions, three-dimensional(3D) displacement vector,and setup time were recorded. The margin of the planning target volume(PTV)was calculated using the Van Herk formula(2.5∑+0.7σ). Between-group comparison was made by paired t test. Results The PF group had a significant smaller setup error in the y-direction than the VB group (2.54±1.79 vs.3.19±2.14 mm,P=0.03),while there were no significant differences in setup errors in the x-or z-direction between the two groups(1.80± 1.48 vs. 1.90± 1.41 mm, P=0.46;2.14± 1.75 vs. 2.25± 1.75 mm,P=0.35). There were no significant differences in rotational setup errors in the Rx-,Ry-,or Rz-direction between the two groups(1.15°±0.76°vs. 1.15°±0.85°, P=0.50;0.71°±0.60°vs. 0.72°±0.43°, P=0.45;0.62°±0.54° vs. 0.46°±0.30°,P=0.06). The PTV margins in the x?,y?,and z?directions were expanded by 5.56, 8.57, and 7.02 mm, respectively, in the PF group, and by 5.62, 9.27, and 7.23 mm,respectively,in the VB group. The proportion of patients with 3D displacement vectors larger than 5 mm was 40% in the PF group and 45% in the VB group.Conclusions For patients undergoing radiotherapy for lung cancer,personalized polyurethane foam with wing boards can,to a certain extent,reduce the setup error in the superior-inferior direction and PTV margin expansion.[Key words] Lung neoplasms/radiotherapy; Polyurethane foam; Vacuum bag; Setup errors;Margin

Objective To analyze the 10-year survival outcome and failure patterns for patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT),aiming to provide reference for optimized treatment for NPC.Methods Clinical data of 866 patients with NPC receiving IMRT from January 2001 to December 2008 were retrospectively analyzed.Survival analysis was performed using the Kaplan-Meier estimator.Univariate analysis was carried out by log-rank test and multivariate analysis was performed using Cox proportional hazards model.Results The median follow-up time was 132 months.The 10-year local recurrence-free survival (LRFS),distant metastasis-free survival (DMFS),progression-free survival (PFS) and disease specific survival (DSS) were 92.0％,83.4％,75.7％ and 78.6％,respectively.A total of 210 patients died including 124 patients (59.0％) from distant metastasis,which was the primary cause of death,and 47 (22.3％) from local regional recurrence.Independent negative factors of DSS included age＞50 years (P=0.00),LDH ≥ 245 IU/L (P=0.00),Hb＜ 120 g/L (P=0.01),T2-T4 staging (P=0.00),N1-N3 staging (P=0.00) and GTV-nx＞20 cm3(P=0.00).The 10-year LRFS,DMFS and DSS of stage Ⅱ NPC patients did not significantly differ after IMRT alone and chemoradiotherapy (P=0.83,0.22,0.23).For patients with stage Ⅲ NPC,the 10-year LRFS and DSS in the chemoradiotherapy arm were significantly higher than those in the IMRT alone (P=0.01,0.01),whereas no statistical significance was observed in the DMFS between two groups (P=0.14).The overall survival of stage Ⅳa+Ⅳb NPC patients is relatively poor.Conclusions IMRT can improve the long-term survival of NPC patients.Distant metastasis is the primary failure pattern.Patients with stage Ⅰ-Ⅱ NPC can obtain satisfactory survival outcomes after IMRT alone.The addition of chemotherapy can further enhance the LRFS and DSS of stage Ⅲ NPC patients.However,the optimal therapeutic strategy remains to be urgently investigated for stage a+ Ⅳb NPC patients.

Objective To compare the setup errors of the negative pressure vacuum air cushion (vacuum bag) and the Orfit body foam fixator (Orfit frame) in radiotherapy for cervical cancer.Methods A total of 40 patients receiving three-dimensional radiotherapy for cervical cancer were enrolled in this study and equally and randomly divided into vacuum bag group and Orfit frame group.And the two groups were divided into Orfit-1 group, Orfit-2 group, vacuum-1 group, and vacuum-2 group according to the treatment course.The Orfit-1 group and vacuum-1 group were the data in the first 12 treatments, while the Orfit-2 group and vacuum-2 group were the data in the following 13 treatments.A cone-beam computed tomography scan was performed before each treatment to analyze setup error and then the body position was corrected to start the treatment.Comparison of continuous data between groups was made by paired t-test, while comparison of categorical data was made by chi-square test.Results There was a significant difference in the setup error in y-axis direction between the Orfit-1 group and the Orfit-2 group (P=0.003) and the setup error in r-axis direction between the vacuum-1 group and the vacuum-2 group (P=0.013).There were no significant differences in the setup errors in four directions (x-axis, y-axis, z-axis, and r-axis) between the Orfit-1 group and the vacuum-1 group (P>0.05).There were significant differences in the setup errors in y-axis and z-axis directions between the Orfit-2 group and the vacuum-2 group (P=0.007;P=0.001).Conclusions The Orfit frame and the vacuum bag have their own advantages and disadvantages in the fixation of body position in radiotherapy for cervical cancer.The setup error can be improved by long vacuum bags, ultrasound bladder capacity scanner, image-guided radiotherapy, or sectional radiotherapy plan.

Objective To develop a MOSAIQ Integration PlatformCHN (MIP) based on the workflow of radiotherapy (RT) and to meet the actual requirements in China and the special needs for the radiotherapy department.Methods MIP used C/S (client-server) structure mode running on the local network in the hospital and its database was based on the Treatment Planning System (TPS) and MOSAIQ database.Five network servers,as the core hardware,supplied data storage and network service based on cloud services.The core software was developed based on Microsoft Visual Studio Platform using C# network programming language.The MIP server could simultaneously offer network service for about 200 workstations,including entry,query,statistics,and print of data.Results MIP had 15 core function modules,such as Notice,Appointment,Billing,Document Management (application/execution),and System Management,which almost covered the whole workflow of radiotherapy.Up to June 2016,the recorded data in the MIP were as follows:13546 patients,13533 plan application forms,15475 RT records,14656 RT summaries,567048 billing records,and 506612 workload records.Conclusions The MIP based on the RT workflow has been successfully developed and used in clinical practice.It is an important part of radiotherapy information system construction with the advantages of intuitive operation,real-time performance,data security,and stable operation.It is digital,paperless,user-friendly,and convenient for the retrieval and statistics of data as well as information sharing and department management,and can significantly improve the efficiency of the department.More functions can be added or modified to enhance its potentials in research and clinical practice.

Objective To monitor and compare the breathing mechanics on PC,VC and PRVC during pneumoperitoneum,and to discuss the significance of the clinic use of PRVC.Method Ninety laparoscopic cholecystectomy patients were equally divided into 3 groups (PC,VC,PRVC).Levels of PES,PAWM,PAP,PaCO2,ETCO2,TV MAP and HR were detected before pneumoperitoneum,and at 5,10,15 and 20 minutes postpneumoperitoneum.Results Pneumoperitoneum made three respiratory patterns with different levels of PAWM,PAP,and PES.PES post-pneumoperitoneum in the VC model was obviously higher than that in the PC and PRVC group.At 10 min post-pneumoperitoneum,levels of PaCO2 and ETCO2 increased obviously in the PC and VC group(P ＜ 0.05).Levels of PaCO2 and ETCO2 were increased in the PC group,but TV level post-pneumoperitoneum was significantly lower than that in the other two groups (P ＜ 0.05).Level of PaCO2 and ETCO2 were increased in the PC and VC group post-pneumoperitoneum,along with increases of MAP and HR (P ＜ 0.05).Levels of MAP and HR in the PRVC group post-pneumoperitoneum were significantly lower than those in the PC and VC group (P ＜ 0.05).Conclusion PRVC mode can effectively reduce the increases of pneumoperitoneum-induced PAWM,PAP,PES,without the unusual increase of PaCO2 and ETCO2 during surgeries,contributing to the stability of vital signs of perioperative patients.