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 manpower allocation and scientific research level of radiotherapists in radiotherapy units in mainland China, aiming to provide reference for the construction of radiotherapist teams.Methods:The questionnaire was designed and produced by the organizer, released in the professional committee, professional group and other channels of the radiotherapist industry, and filled out by the technical person in charge of the radiotherapy unit through the online questionnaire survey. The collection time started from mid-May 2021 to mid-June 2021.Results:A total of 558 effective questionnaires filled out by radiotherapy units. The radiotherapy institutions participating in the survey had a total of 5500 radiotherapists, including 3702 males and 1798 females, 3754 with a bachelor's degree, 371 who are currently studying or have obtained a master's degree, 21 who are currently studying or have already obtained a doctoral degree, 3642 with junior or lower titles, 1580 with intermediate titles, and 278 with senior titles. In 2020, radiotherapists from 193 units published articles, those from 81 units received project funding, and those from 56 units obtained patent authorization, and those from 15 units had scientific research transformation. The participating units had a total of 1080 large-scale radiation therapy equipment. In 2020, the daily average number of radiotherapy patients was 47 900, the average daily load of accelerator patients was 44.35, and the average workload index per capita was 8.71. The average daily radiotherapy patients in county-level or below, city-level, and provincial-level institutions were 25.78, 65.68, and 173.76, respectively, and the per capita workload index was 5.22, 8.09, and 10.11.Conclusions:Compared with the 2019 survey, the educational background of radiotherapists in mainland China has been improved, and the title structure has been optimized to a certain extent, and the workload of large-scale radiotherapy units is larger than that of grass-roots units.

Objective:To investigate and analyze the basic occupational situation of Chinese radiotherapists and to provide references for the development and construction of the radiation therapist team in China.Methods:Between May 7, 2021 and June 15, 2021, this survey was conducted using a self-designed questionnaire, which was distributed and collected in the form of online survey to conduct a statistical analysis of the basic situation of radiotherapists in 30 provincial-level administrative regions in China.Results:A total of 2 928 valid questionnaires were collected from 30 provincial-level administrative regions. The ratio of male to female and average age of the participants were 69∶31 and 35 years (18-65), respectively. According to the survey result, 84.7% of the participants came from Tertiary A-level hospitals. In terms of educational background, the participants with doctoral, master, undergraduate, junior-college, and technical-secondary degrees accounted for 0.2%, 6.9%, 76.6%, 14.9%, and 1.4%, respectively. In terms of title, full senior technologists, associate senior technologist, technologist-in-charge, technologist, and technician in the participants accounted for 0.5%, 5.8%, 32.5%, 52.2%, and 8.2%, respectively. The participants with years of employment of 0-, 5-, 10-, 20-y accounted for 33.74%, 25.79%, 25.51%, and 14.96%, respectively. The majors of the participants included medical imaging/imaging technology (45.9%), clinical medicine (19.1%), and biomedical engineering (11.9%).Conclusions:Chinese radiotherapists tend to be younger and are rapidly increasing in number. Employers should attach importance to the career planningand continuing education of radiotherapists to improve their technical skills, in order to fully satisfy the demand for radiotherapists in the new era.

Objective:Before the radiotherapy was performed, patients with pelvic tumors were analyzed for the consistency of bladder filling in the three steps of " Immobilization" , " CT Simulation" and " X-ray Simulation" .Methods:In 2014, 105 patients (68 cases of cervical cancer, 32 cases of rectal cancer, 3 cases of vaginal cancer and 2 cases of prostate cancer) with pelvic tumor radiotherapy were randomly assigned to monitor bladder urine volume to a target urine volume of 400 ml. First, patient were exhorted to empty the bladder, and the bladder volume meter BVI 9400 was used to measure the urine volume of the patient after emptying of the bladder. The patient immediately drank about 540 ml of water and suppressed urine, measurements were taken every 0.5 h. At the same time, when the patient complained of " urgency of urine" , bladder urine volume would be measured again and the time would also be recorded. Every other half an hour (emptying, 0.5 h after emptying, 1.0 h after emptying), when complaining of " urgency of urine" , when actually performing urine volume and time were described as: U 0 and t 0, U 0.5 and t 0.5, U 1.0 and t 1.0, U t and t, U T and T. Results:There was a statistically significant difference in gender and age, and women had stronger ability to urinate than men U 1.0( P=0.003), young people had stronger ability to urinate than middle-aged U 1.0( P=0.002). In the three-step comparison, there was no statistically difference between 1 hour after emptying urine volume U 1.0( P=0.177) and the actually performing urine volume U T ( P=0.052). And the final urine volume was concentrated at 298-526 ml. After the patient emptied the urine volume and complained of " urgency of urine" , the time slot was t=(75.2±49.9) min, with the urine volume of U t=(331.2±140.3) ml. And there was no statistically difference between U t and U T ( P=0.198) at X-ray Simulation. Conclusions:The patient emptied the bladder and immediately drank 540 ml of water. After 1 hour of suppressing urine, he complained of " urgency of urine" and achieved the target urine volume (400 ml). At this time, the bladder urine volume U 1.0 was consistency in the immobilization, CT Simulation, and X-ray Simulation.

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 investigate the effect of body mass index (BMI) on setup errors in intensity-modulated radiotherapy for cervical cancer and explore the optimal position for patients with different BMI without taking into account the rotation error and the changes in target area and adjacent organs.Methods:A total of 90 patients were divided into three groups according to their BMI: light weight group (BMI≤18.4 kg/m 2), normal weight group (18.5 kg/m 2≤BMI≤23.9 kg/m 2) and overweight group (BMI≥24 kg/m 2). Thirty patients were assigned into each group including15 patients in the supine position and 15 patients in the prone position. In total, 2 250 sets of CBCT scan data of 90 patients were obtained. The setup errors were recorded and analyzed in each group. The margins of the optimal position were calculated according to the formula of M PTV=2.5+ 0.7. Results:When BMI was not taken into account, there was no significant difference in the setup errors between the supine and prone positions in the x, y and z directions (all P>0.05). When BMI was considered, the setup error in the supine position were significantly smaller than those in the prone position in the x and y directions in the light weight group, whereas there was no significant difference in the setup errors between the supine and prone positions in the z direction ( P>0.05). The corresponding M PTV in the supine position was 4.76, 4.27 and 5.73 mm, respectively. In the normal weight group, there was no significant difference in the setup errors between the supine and prone positions in the x and y directions (both P>0.05), whereas the setup error in the prone position was smaller than that in the supine position in the z direction. The corresponding M PTV in the prone position were 6.42, 10.21 and 4.91 mm, respectively. In the overweight group, there was no significant difference in the setup errors between the supine and prone positions in the x and z directions (all P>0.05), whereas the setup error in the prone position was smaller than that in the supine position in the y direction. The corresponding M PTV in the prone position were 5.88, 5.26 and 5.32 mm, respectively. Conclusions:Without taking into account the rotation error and the changes in target area and adjacent organs, when the BMI≤18.4, the supine position is recommended. When the BMI≥18.5, it is better to choose the prone position.

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 analyze the incidence and risk factors of benign liver space-occupying mass in patients with chronic hepatitis B (CHB) and the ultrasound features that differentiate these masses from small hepatocellular carcinoma. METHODS: We retrospectively analyzed the color Doppler and clinical data of 17 721 patients with CHB treated in the Hepatology Unit of Nanfang Hospital between January, 2016 and December, 2017. The data were compared with those of 21629 healthy control subjects undergoing routine physical examination in the Center of Heath Management of Nanfang Hospital during the same period. RESULTS: Compared with the control subjects, the patients with CHB had significantly higher incidences of hepatic cysts (11.8% 8.7%, < 0.05), hepatic hemangioma (8.2% 1.6%, < 0.05) and hepatic cirrhosis nodules (20.6% 2.4%, < 0.05). The incidences of hepatic cysts and cirrhosis nodules increased with age and was significantly higher in male than in female patients ( < 0.001). The highest incidence of hepatic hemangioma was found in CHB patients aged 30-49 years without a gender difference (>0.05). Sonographically, the benign liver masses commonly showed homogeneous echo within the lesion with clear boundaries and regular shape. Hepatic hemangioma was distinctively hyperechoic in 83.32% (1579/1895) of the patients, while small hepatocellular carcinoma presented with weaker peripheral and internal blood flow signals with a lower flow velocity in the arteries and a higher flow velocity in the portal vein. Liver cirrhosis nodules mostly showed a mixture of strong and weak echoes (79.60%; 7637/9595) without blood flow signal within or around the nodule; an increased volume of the nodule accompanied by heterogeneous echoes within the nodule indicated an increased probability of malignant lesion. Hepatic cysts often displayed no echo within the lesion, but the echo could be enhanced posteriorly. CONCLUSIONS The patients with CHB are at a significantly higher risk of developing hepatic cysts, hepatic hemangiomas and hepatic cirrhosis nodules than the control population, and an older age and the male gender are associated with a higher incidence of hepatic cysts or cirrhosis. The differences in the sonographic and hemodynamic features can help to differentiate hepatic benign mass from malignant lesions, and kinetic changes in sonography can be used to monitor potential malignant transformation of the cirrhotic lesions.

OBJECTIVE: To compare the efficacy and safety of different antiviral and antifibrotic regimens in patients with chronic hepatitis B (CHB) and hepatic fibrosis and the incidence of hepatocellular carcinoma (HCC) associated with these therapies. METHODS: A total of 840 patients with CHB and concurrent hepatic fibrosis, who received antiviral therapy in Nanfang Hospital between June, 2010 and June, 2018, were enrolled in this follow-up cohort study. The patients were assigned to 3 cohorts matched for gender, age (difference≤5 years), HBeAg status and liver stiffness measurement (LSM) for treatment with one of the 3 antiviral drugs, namely entecavir, tenofovir dipivoxil and adefovir dipivoxil; each cohort was divided into 2 groups, with one of the groups having a combined treatment with Fufang Biejiaruangan tablet. The cumulative negative conversion rate of HBV DNA, normalization rate of ALT, hepatic fibrosis regression and the incidence of HCC were compared among the 3 cohorts and across the 6 groups at 144 weeks. RESULTS: A total of 749 patients were available to follow-up at 144 weeks. Compared with the baseline data, the cumulative negative conversion rate of HBV DNA increased gradually and the abnormal rate of ALT decreased significantly over time during the treatment in all the 6 groups (all < 0.001). Compared with the any of the antiviral drugs used alone, the combined treatments all resulted in significantly better antifibrotic effects (χ=11.345, χ=10.160, χ=6.358; all < 0.05). At 144 weeks, the incidence of HCC were 2.2%, 1.7%, 1.7% and 3.3% in enecavir group, enecavir with Biejiaruangan tablet group, adefovir group, and adefovir with Biejiaruangan tablet group, respectively, showing no significant difference between the two cohorts (4 groups; χ=6.813, =0.138). None of the patients in the 2 groups with tenofovir treatment had HCC by the end of the observation. CONCLUSIONS Antiviral therapy combined with antifibrotic therapy can effectively reverse hepatic fibrosis and reduce the incidence of HCC in patients with CHB; among the 3 antiviral drugs, tenofovir dipivoxil can be a better option for reducing the incidence of HCC in these patients.
Antiviral Agents ; Carcinoma, Hepatocellular ; etiology ; DNA, Viral ; Follow-Up Studies ; Hepatitis B e Antigens ; Hepatitis B virus ; Hepatitis B, Chronic ; complications ; Humans ; Liver Cirrhosis ; complications ; Liver Neoplasms ; etiology ; Prospective Studies

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.