Objective:To analyze and compare the interfractional setup errors between two body posi-tioning fixation methods(lithotomy position with carbon fiber full-body fixation frame vs.conventional carbon fiber body fixation frame combined with thermoplastic membrane)in radical radiotherapy for pros-tate cancer,and to calculate the clinical target volume(CTV)to planning target volume(PTV)margin(MPTV)for both methods to optimize immobilization techniques and radiotherapy workflows.Methods:A retrospective analysis was conducted on 37 consecutive patients who underwent radical prostate radio-therapy at Peking University First Hospital between August 2021 and March 2023.The patients were di-vided into two groups based on the immobilization method:Group A(18 patients,450 CBCT image sets)used a carbon fiber whole-body fixator in the lithotomy position,while Group B(19 patients,461 CBCT image sets)used a conventional carbon fiber fixator combined with a thermoplastic mask.All the patients underwent daily cone-beam computed tomography(CBCT)image guidance.Bone registration combined with manual registration was used to obtain the setup error data in the left-right(X),cranio-caudal(Y)and anterior-posterior(Z)directions.The positioning errors of the two groups were compared by using the independent sample t-test,the Mann-Whitney U test and the chi-square test.The average positioning error,systematic positioning error(Σ)and random positioning error(δ)were calculated,and the CTV-PTV extension distance was calculated by using the(MPTV=2.5Σ+0.7δ).Results:The analysis of the setup errors in the three-dimensional direction showed significant differences between the two groups(all P＜0.01).Specifically,the median(quartile)absolute values of the errors in the X,Y,and Z di-rections of group A were[0.40(0.20,0.70)cm,0.50(0.30,0.80)cm,and 0.35(0.20,0.60)cm],respectively.In group B,the corresponding values were significantly reduced to[0.20(0.10,0.40)cm,0.40(0.20,0.70)cm and 0.20(0.10,0.40)cm].The results of Mann-Whitney U test showed that the differences in each direction were highly statistically significant(X:z=-6.86;Y:z=-2.76;Z:z=-5.71).The cumulative distribution ratio of the setup error displacement within 0.5 cm in the X,Y,and Z directions in group A and group B were 297(66.0％)and 408(88.5％)(P＜0.01),250(55.6％)and 285(61.8％)(P=0.055),308(68.4％)and 391(84.8％)(P＜0.01),re-spectively.The CTV-PTV margins in three directions were X 0.66 cm in group A and 0.35 cm in group B;Y0.67 cm and 0.45 cm;Z 0.54 cm and 0.42 cm.Conclusion:Conventional carbon fiber human body fixator combined with thermoplastic film can significantly reduce the setup error.However,the car-bon fiber whole-body fixator in the lithotomy position demonstrated larger setup errors in the X,Y,and Z directions compared with the conventional fixator combined with a thermoplastic mask,indicating the need for further workflow optimization.Given that the lithotomy position is essential for transperineal ultrasound-guided techniques,further research and improvements are required to achieve higher positioning accuracy.

Objective:To evaluate the acute toxicities and related influencing factors of vertebral-body-sparing proton craniospinal irradiation (VBSpCSI) using pencil beam scanning (PBS) technology in pediatric patients, and to assess spinal growth and survival outcomes.Methods:A retrospective analysis was conducted on 70 pediatric patients treated with PBS-based VBSpCSI at Hebei Yizhou Cancer Hospital between January 2020 and December 2022, and continued to follow up until November 2023. Acute toxicities were assessed, and linear regression analysis combined with receiver operating characteristic curve were employed to investigate the dose-effect relationship between vertebral dose and toxicities. Spinal growth after radiotherapy was evaluated by measuring the Cobb angle on follow-up MRI. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.Results:The median age of patients at the time of irradiation was 6 years (range, 2-16 years). Two patients (3%) developed grade ≥3 gastrointestinal toxicities, while 7 patients (10%) experienced grade 1 radiation-induced esophagitis. The nadirs of white blood cell count (WBC), absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) during treatment were significantly negatively correlated with vertebral V 5 Gy ( P=0.009, 0.006, 0.001) and vertebral V 20 Gy ( P=0.007, 0.011, <0.001). When vertebral V 5 Gy<86.5% and vertebral V 20 Gy<73.2%, the incidence of grade ≥3 myelosuppression was significantly reduced ( P<0.001, =0.001). Additionally, younger patient age (in months) and concurrent chemotherapy were also significantly associated with increased acute hematologic toxicity. Among 43 patients with MRI follow-up, no scoliosis, kyphosis, or chronic lumbosacral pain was observed. The 3-year OS and PFS rates were 95.7% and 86.4%, respectively. Conclusions:PBS-based VBSpCSI in pediatric patients demonstrates manageable acute toxicities, with a clear dose-effect relationship between vertebral V 5 Gy , V 20 Gy and hematologic toxicities, and the incidence of non-hematological toxicities remains low. No adverse effects on spinal growth or survival outcomes were observed in the short term.

Objective:To analyze and compare the interfractional setup errors between two body posi-tioning fixation methods(lithotomy position with carbon fiber full-body fixation frame vs.conventional carbon fiber body fixation frame combined with thermoplastic membrane)in radical radiotherapy for pros-tate cancer,and to calculate the clinical target volume(CTV)to planning target volume(PTV)margin(MPTV)for both methods to optimize immobilization techniques and radiotherapy workflows.Methods:A retrospective analysis was conducted on 37 consecutive patients who underwent radical prostate radio-therapy at Peking University First Hospital between August 2021 and March 2023.The patients were di-vided into two groups based on the immobilization method:Group A(18 patients,450 CBCT image sets)used a carbon fiber whole-body fixator in the lithotomy position,while Group B(19 patients,461 CBCT image sets)used a conventional carbon fiber fixator combined with a thermoplastic mask.All the patients underwent daily cone-beam computed tomography(CBCT)image guidance.Bone registration combined with manual registration was used to obtain the setup error data in the left-right(X),cranio-caudal(Y)and anterior-posterior(Z)directions.The positioning errors of the two groups were compared by using the independent sample t-test,the Mann-Whitney U test and the chi-square test.The average positioning error,systematic positioning error(Σ)and random positioning error(δ)were calculated,and the CTV-PTV extension distance was calculated by using the(MPTV=2.5Σ+0.7δ).Results:The analysis of the setup errors in the three-dimensional direction showed significant differences between the two groups(all P＜0.01).Specifically,the median(quartile)absolute values of the errors in the X,Y,and Z di-rections of group A were[0.40(0.20,0.70)cm,0.50(0.30,0.80)cm,and 0.35(0.20,0.60)cm],respectively.In group B,the corresponding values were significantly reduced to[0.20(0.10,0.40)cm,0.40(0.20,0.70)cm and 0.20(0.10,0.40)cm].The results of Mann-Whitney U test showed that the differences in each direction were highly statistically significant(X:z=-6.86;Y:z=-2.76;Z:z=-5.71).The cumulative distribution ratio of the setup error displacement within 0.5 cm in the X,Y,and Z directions in group A and group B were 297(66.0％)and 408(88.5％)(P＜0.01),250(55.6％)and 285(61.8％)(P=0.055),308(68.4％)and 391(84.8％)(P＜0.01),re-spectively.The CTV-PTV margins in three directions were X 0.66 cm in group A and 0.35 cm in group B;Y0.67 cm and 0.45 cm;Z 0.54 cm and 0.42 cm.Conclusion:Conventional carbon fiber human body fixator combined with thermoplastic film can significantly reduce the setup error.However,the car-bon fiber whole-body fixator in the lithotomy position demonstrated larger setup errors in the X,Y,and Z directions compared with the conventional fixator combined with a thermoplastic mask,indicating the need for further workflow optimization.Given that the lithotomy position is essential for transperineal ultrasound-guided techniques,further research and improvements are required to achieve higher positioning accuracy.

Objective:To evaluate the acute toxicities and related influencing factors of vertebral-body-sparing proton craniospinal irradiation (VBSpCSI) using pencil beam scanning (PBS) technology in pediatric patients, and to assess spinal growth and survival outcomes.Methods:A retrospective analysis was conducted on 70 pediatric patients treated with PBS-based VBSpCSI at Hebei Yizhou Cancer Hospital between January 2020 and December 2022, and continued to follow up until November 2023. Acute toxicities were assessed, and linear regression analysis combined with receiver operating characteristic curve were employed to investigate the dose-effect relationship between vertebral dose and toxicities. Spinal growth after radiotherapy was evaluated by measuring the Cobb angle on follow-up MRI. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.Results:The median age of patients at the time of irradiation was 6 years (range, 2-16 years). Two patients (3%) developed grade ≥3 gastrointestinal toxicities, while 7 patients (10%) experienced grade 1 radiation-induced esophagitis. The nadirs of white blood cell count (WBC), absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) during treatment were significantly negatively correlated with vertebral V 5 Gy ( P=0.009, 0.006, 0.001) and vertebral V 20 Gy ( P=0.007, 0.011, <0.001). When vertebral V 5 Gy<86.5% and vertebral V 20 Gy<73.2%, the incidence of grade ≥3 myelosuppression was significantly reduced ( P<0.001, =0.001). Additionally, younger patient age (in months) and concurrent chemotherapy were also significantly associated with increased acute hematologic toxicity. Among 43 patients with MRI follow-up, no scoliosis, kyphosis, or chronic lumbosacral pain was observed. The 3-year OS and PFS rates were 95.7% and 86.4%, respectively. Conclusions:PBS-based VBSpCSI in pediatric patients demonstrates manageable acute toxicities, with a clear dose-effect relationship between vertebral V 5 Gy , V 20 Gy and hematologic toxicities, and the incidence of non-hematological toxicities remains low. No adverse effects on spinal growth or survival outcomes were observed in the short term.

8-hydroxy-2'-deoxyguanosine (8-OHdG) is a sensitive and stable biomarker for evaluating DNA oxidative damage. A rapid and sensitive colloidal gold immunochromatographic strip was developed for 8-OHdG detection by a competitive method. The sample pad (glass cellulose film), bonding pad (glass cellulose film), nitrocellulose film and absorbent pad were pasted on the polyvinyl chloride (PVC) base plate to construct the test strip. Colloidal gold (AuNPs) was prepared by the reduction of chloroauric acid with sodium citrate. 8-OHdG antibody (Ab) was coated on the outer layer of AuNPs to form Ab@AuNPs as a probe. Bovine serum albumin (BSA) and 8-OHdG were conjugated with carbodiimide hydrochloride to prepare an artificial antigen, which was used as the coating antigen of detection line. Goat anti mouse polyclonal antibody IgG was used as the coating antibody of control line. The experimental parameters were optimized including the type of nitrocellulose membrane, the formula of loading solution, and the spraying amount of gold labeled antibody. The results showed that the appropriate nitrocellulose membrane was CN 95. The optimal loading solution included BSA (1%), Tween-20 (3%), sucrose (3%) and NaCl (0.9%). The optimal spraying amount of gold labeled antibody was 4 μL. 8-OHdG can be detected by the strip under visible light, and the level of 8-OHdG in urine can be preliminarily determined by comparing the color intensity of T line and C line. The 8-OHdG concentration in urine was further calculated by the gray value of T line and the threshold of detection was 2.55 μg/L. This colloidal gold immunochromatographic strip is simple, rapid and specific for detecting 8-OHdG in human urine to preliminarily evaluate the human status.
8-Hydroxy-2'-Deoxyguanosine ; Animals ; Antibodies, Monoclonal ; Gold ; Gold Colloid/chemistry* ; Metal Nanoparticles ; Mice ; Sensitivity and Specificity

ObjectiveBy testing trace elements content and sulfur isotopic composition of 12 primary Cinnabaris ore samples from Xingren city and Danzhai county of Guizhou province， to explore the feasibility of identifying the origin of Chinese medicinal materials based on the trace element content-isotopic tracer technique. MethodThe contents of 50 trace elements in Cinnabaris were determined by inductively coupled plasma mass spectrometry， and cluster analysis and principal component analysis （PCA） were performed by OriginPro 2018 software. At the same time， the sulfur isotopic composition in Cinnabaris samples was determined by gas stable isotope mass spectrometry. ResultThe trace element content and sulfur isotopic composition of Cinnabaris in Xingren and Danzhai were quite different， the contents of vanadium （V）， chromium （Cr）， copper （Cu）， arsenic （As）， strontium （Sr）， barium （Ba）， thallium （Tl）， aluminum （Al）， titanium （Ti） and manganese （Mn） in Cinnabaris from Lanmuchang were significantly higher than those in the Sixiangchang. The results of cluster analysis showed that the trace element content of 6 Cinnabaris samples from Sixiangchang was close and had a good correlation， while the contents of trace elements in 6 samples from Lanmuchang were far apart. The PCA biplots showed that 6 samples of Cinnabaris from Sixiangchang concentrated on the negative half axis of principal component 1 and 2， while 6 samples from Lanmuchang concentrated on the positive half axis of principal component 1 and 2. The δ³⁴S values of Cinnabaris samples from Lanmuchang and Sixiangchang were 0.573%-0.884% and 2.233%-2.364%， scatter diagram showed that the δ³⁴S values of Cinnabaris from the same origin were distributed in the same area， but δ³⁴S values of samples from the two producing areas were different， which indicates that the formation mechanism of Cinnabaris was different. ConclusionBased on the analysis of Cinnabaris from two producing areas in Guizhou province， it is found that Cinnabaris from different producing areas has different trace element composition， and the correlation of trace elements in samples from the same producing area is good， and the composition of δ³⁴S in Cinnabaris from different producing areas is different. The results show that trace element-isotopic tracer technique has great potential in the study of origin identification and traceability of mineral Chinese medicine， which can provide new research ideas for origin traceability， identification and quality evaluation of Chinese medicinal materials.

Objective To evaluate the incidental irradiation to the axillary levels Ⅰ,Ⅱ and Ⅲduring the whole breast radiotherapy after breast conserving surgery(BCS)without axillary lymph node dissection(ALND)in breast cancer(BC)patients.Methods A retrospective analysis was performed on the consecutive 42 cases of T1-2N0M0stage BC patients with sentinel lymphnode biopsy(SLNB)and BCS but without ALND.The axillary lymph nodes of Ⅰ,Ⅱ and Ⅲ were delineated according to RTOG atlas guideline.Three radiotherapy plans including conventional tangential field(CTF),three-dimensional conformal radiotherapy(3D-CRT)and forward-planned intensity-modulated radiotherapy(IMRT)for whole breast irradiation were devised for each case.The Prescription dose was 50 Gy per 25 fractions.Doses to axillary levels(Ⅰ-Ⅲ)were evaluated.Results The mean doses delivered to axillary by the three techniques(CTF,3D-CRT and IMRT)were(40.1 ±6.8),(35.4 ±8.3),(32.9 ±7.0)Gy for level Ⅰ(F＝10.269,P＜0.05),(33.2 ±7.1),(30.6 ±6.7),(30.4 ±7.0)Gy for level Ⅱ(P＞0.05)and(9.6 ±6.8),(6.4 ±4.5),(5.2 ±3.7)Gy for level Ⅲ(F ＝8.377,P ＜0.05),respectively.V50(volume receiving 50 Gy)for the three techniques were 21.3％,27.6％,9.6％for level Ⅰ(F＝13.161,P＜0.05),12.9％,15.9％,8.3％for level Ⅱ(F＝2.750,P＜0.05)and 0.4％,0.1％and 0％for level Ⅲ(P＞0.05),respectively.Conclusions The doses coverage to axillary levelsⅠ-Ⅲwere all limited in the three techniques.Therefore,it is necessary to assess the risk of axillary lymph node metastasis adequately to develop individualized radiotherapy plans.

Objective To analyze the adverse events in patients diagnosed with oligometastasized castration resistant prostate carcinoma (CRPC) receiving radiotherapy for the primary and metastatic prostate carcinomas.Methods Twenty patients with oligometastasized CRPC admitted to our hospital between 2011 and 2015 were treated with image-guided volumetric modulated arc therapy (VMAT).The dose for prostate+ seminal vesicle was 76 Gy/38 f,46 Gy/23 f for the pelvic lymph node and the median dose for the metastatic lesions was 60 Gy (52-66)/23 f.Relevant clinical data and adverse events were analyzed.Results All patients completed the radiotherapy.Only 1 patient showed grade Ⅲ urinary obstruction and received catheterization.In terms of acute adverse events of ≥ grade Ⅱ,urinary tract was observed in 4 cases (20％),rectum in 2 (10％) and blood system in 2(10％).The rectal V50 was correlated with acute adverse events of ≥ grade Ⅱ.The median follow-up time was 24.2 months.No patient suffered from late adverse events of ≥ grade Ⅱ.All cases showed a decline in the level of prostate specific antigen (PSA) after radiotherapy.The median PSA reduction rate was 99％.Among them,16 cases (80％) had a PSA reduction rate of over 90％.Conclusions It is safe and efficacious to perform radical dosage radiotherapy for primary and metastatic prostate carcinomas in patients with oligometastasized CRPC.

Objective To apply real-time transperineal ultrasound ( TPUS) to monitor the intra-fractional prostate motion,collect and analyze the data of the prostate motion,aiming to provide evidence for the optimization of the target area and plan of radiotherapy for prostate cancer. Methods TPUS is a non-invasive monitoring technique that utilizes an automatic scanning ultrasound probe to dynamically monitor and correct the motion of organs during radiotherapy. In this study, TPUS was utilized to collect 1588 intra-fractional data of 70 patients with prostate cancer. Prior to each cycle of radiotherapy,CBCT was adopted to correct the errors between intra-factional data by using VMAT. During radiotherapy, real-time ( once per second) ultrasound images were acquired to monitor the 3D motion of the prostate on the x (left+,right-),y (cranial+, caudal-), and z ( abdominal+, dorsal-) axes, emphasizing the analysis of 4D motion of the prostate. Results All patients successfully completed the treatment and data collection. The median time of effective monitoring per faction was 179 seconds (132-286 seconds). During 95% of the monitoring time,the distance of prostate motion was 2. 22 mm in the left direction,2. 17 mm in the right,2. 08 mm in the cranial, 1. 98 mm in the caudal,2. 44 mm in the abdominal and 2. 97 mm in the dorsal direction,respectively. In the x,y and z axes,the percentage of time in which the distance of prostate motion less than 1 mm among the total time was 83. 07%,85. 46% and 78. 27%,respectively,whereas 97. 70%,97. 87% and 96. 45% for＜3 mm, respectively. Conclusions TPUS is a non-invasive real-time monitoring technique,which can detect the 4D motion of the prostate during radiotherapy. By using VMAT,the range of prostate motion is relatively small, and the motion range is less than 3 mm in each direction within 95% of the time.

Objective To study the radiosensitizing effect of 2'-hydroxyflavanone (2'-HF) on prostate cancer cells,and to preliminarily investigate its mechanism.Methods Colony formation assay,tert-butylhydroperoxide (TBHP) oxidative stress assay,Hoechst staining,and apoptosis flow cytometry using Annexin V-FITC and propidium iodide (PI) were performed to measure the impact of 2'-HF on the radiosensitivity of VCaP prostate cancer cells.Western blot was used to determine the effects of 2'-HF on expression of AKT,phosphorylated AKT (p-AKT),and aldo-keto reductase 1 C3 (AKR1 C3) in VCaP cells and preliminarily investigate the mechanism.Data were analyzed by t test and factorial analysis of variance.Results The results of colony formation assay indicated that after exposure to radiation,VCaP cells treated with 2'-HF had a significantly lower proliferation level than cells in the control group (P=0.010),yielding a sensitization enhancement ratio of 1.19.The resuhs of TBHP oxidative stress assay suggested that VCaP cells treated with 2'-HF had significantly weaker anti-oxidative capacity than cells in the control group (P=0.015).Hoechst staining and apoptosis flow cytometry with Annexin V-FITC and PI indicated that 2'-HF treatment plus irradiation significantly enhanced apoptosis in VCaP cells (P=0.001.The results of Western blot suggested that 2'-HF treatment significantly inhibited the protein expression of p-AKT and AKR1C3 in VCaP cells (P=0.013 and P=0.016).Conclusions 2'-HF can enhance the radiosensitivity of prostate cancer cells,which is probably associated with its inhibitory effects on AKT pathway and AKR1C3 expression in prostate cancer cells.