RESUMEN
Objective:To investigate the influence of left atrial size on the ablation efficacy, cardiac morphology and function after valve replacement combined with X-type radiofrequency ablation on posterior wall of left atrium.Methods:From January 2015 to December 2019, 416 patients with mitral valve disease complicated with atrial fibrillation were divided into two groups according to the size of left atrium(Anteroposterior diameter 60 mm). Valve replacement combined with " X" radiofrequency ablation on posterior wall of left atrium was performed. The clinical data were analyzed retrospectively.Results:Except for the AF types, gender, length of stay and postoperative complications, other clinical data, operative and perioperative indicators were better in small left atria group(SLA)than in large left atria group(LLA). The differences were statistically significant( P<0.05). Fractional shortening(FS), ejection fraction(EF) in SLA at any time point were higher than that in LLA, P<0.05. The sinus rhythm conversion rates, the change rate of LA anteroposterior diameter in SLA at postoperative time points were higher than that in LLA, P<0.05. There was no significant difference of cardiac troponin(cTn) and myoglobin(MYO) between the two groups in 6 months after operation, P>0.05. The B-type natriuretic peptide(BNP), cTn, MYO in the other time points were lower than that in LLA, P<0.05. Conclusion:Larger left atrium reduces the rate of sinus rhythm conversion and maintenance in patients undergoing valve replacement combined with fibrillation ablation. There were worse ventricular remodeling and cardiac function recovery. Preoperative evaluation of left atrial size is helpful for prognosis.
RESUMEN
Objective Long non-coding RNA(lncRNA) are aberrantly expressed in breast cancer(BC) and strongly associated with its survival prognosis. The aim of this study is to investigate the expression and effect of IncRNA SPATA31D5P on the invasion and migration capacity of breast cancer cells through adsorption of miR-320a. Methods Totally 30 cases of BC tissues and paraneoplastic tissues were collected, and the expression levels of SPATA31D5P in BC tissues and BC cell lines were detected by Real-time PCR. MDA-MB-231 cells were transfected with SPATA31D5P siRNA interference vector, and cell proliferation, invasion and migration capacity were determined using the cell counting kit-8 assay (CCK-8), 5-ethynyl-2'- deoxyuridine(EdU), Transwell and wound-healing assay respectively. And cell cycle and apoptosis were detected by flow cytometry. Bioinformatics approachs were used to screen for miRNAs that could bind complementarily to SPATA31D5P, and the regulatory effect of SPATA31D5P on miR-320a was detected by Real-time PCR and dual luciferase reporter assay. Results SPATA31D5P levels were significantly higher in BC tissues than in adjacent normal breast tissues, and SPATA31D5P expression was higher in each BC cell line than in normal breast epithelial cells MCF10 A. The level of SPATA31D5P in the interference group was 0. 288±0. 052, which was lower than that of the blank control group 1. 114±0. 096 and negative control (NC) group 1. 079±0. 128 (P< 0. 01). The proliferation activity of MDA- MB-231 cells in the interfered group was significantly reduced and apoptotic rate was obviously increased compared to the NC and control groups (P<0. 01) ;the Gj phase block was observed in the interfered group; the scratch healing rate and number of perforated cells in the interference group were (14. 36 ± 1. 75) % and (26±1.52), which were lower than (52. 25± 1.87)% and ( 67. 33 ± 2. 91 ) of the NC group (PcO.Ol). Dual luciferase experiments confirmed that SPATA31D5P could directly regulate miR-320a expression and luciferase activity. Conclusion SPATA31D5P is highly expressed in BC, interfering with SPATA31D5P expression effectively inhibits the proliferation, migration and invasion of MDA-MB-231 cells, and the mechanism may be related to the targeted regulation of miR-320a.
RESUMEN
Objective:To help clinicians simplify the post-processing operations of structures by developing rapid processing software for target area and organs at risk structures based on ESAPI.Methods:SmartStructure script software was developed based on ESAPI, verified and evaluated in clinical work. 10 cases of rectal cancer receiving neoadjuvant radiotherapy, 10 breast cancer treated with postoperative radiotherapy, 10 cervical cancer receiving postoperative radiotherapy, 10 nasopharyngeal carcinoma receiving radical radiotherapy and 10 lung stereotactic body radiotherapy (SBRT) were selected, and different types of tumors had different post-processing operations of structures. In each case, three methods were used for post-processing of structures. In the control group (manual group), normal manual processing was employed. In the experimental group 1(SmaStru-N group), scripts without templates were utilized. In the experimental group 2(SmaStru-P group). scripts combined with templates were adopted. The processing time of the three methods was compared. Clinicians scored the scripting software from multiple aspects and compared the feeling scores of scripting software and manual operation.Results:All three methods can be normally applied in clinical settings. The error rate in the manual group was 7.0%, 3.0% in the SmaStru-N group 0% in the SmaStru-P group, respectively. Compared with the manual method, SmaStru-N shortened the processing time of target area and organs at risk by 60.9% and 93.3% for SmaStru-P. In addition, SmartStructure was superior to manual method in terms of using feeling scores. Clinicians gave lower score for the" applicability" and" simplicity" , and higher score on the" accuracy" and" efficiency" .Conclusions:Compared with conventional manual structure processing method, SmartStructure software can rapidly and accurately process all structures of the target area and organs at risk, and its advantages become more obvious with the increasing number of structures that need to be processed. SmartStructure software can meet clinical requirements, reduce the error rate, elevate processing speed, improve the working efficiency of clinicians, providing basis for the development of adaptive radiotherapy.
RESUMEN
Radiation therapy plays an important role in the adjuvant treatment of patients with early endometrial carcinoma. Vaginal stump is a common site of disease failure for early endometrial carcinoma patients with intermediate-high risk factors for recurrence. Compared with external beam radiotherapy, vaginal brachytherapy (VBT) can achieve comparable local control rate with fewer toxicities. In this article, research progresses upon the application of VBT in patients with early endometrial carcinoma after hysterectomy were investigated from multiple perspectives of the selection of patients, the selection of vaginal applicator, factors influencing dose distribution, image-guided adaptive brachytherapy, the design and implementation of radiotherapy regime. In addition, the application of intensity-modulated VBT and the usage of novel quality assurance equipment were also discussed.
RESUMEN
Objective:To compare the dosimetric parameters and plan complexity between newly-delicated HyperArc (HA) and conventional volumetric-modulated arc therapy (VMAT) in the treatment of brain metastases.Methods:For 26 patients with brain metastases, HA, conventional coplanar (Cop) and non-coplanar (Non-cop) VMAT plans with a prescription dose of 9 Gy 3fx or 6 Gy 5fx were generated. The dosimetric parameters for planning target volume (PTV), RTOG conformity index (RTOG CI), Paddick CI, homogeneity index (HI), gradient index (GI), maximum dose (D max) of brainstem and dose-volume parameters of brain-PTV(V 2Gy-V 26Gy) were statisticaly compared among these three approaches. In addition, the monitor unit (MU) and the plan complexity parameters (including MCSv and AlPO) were statistically compared. Results:To prevent missed targets during treatment, all plans were established with RTOG CI of greater than 1.1. For Paddick CI, HA provided significantly higher conformity (0.89±0.019) than Non-cop (0.87±0.036, P=0.001) and Cop (0.88±0.017, P=0.003) VMAT. For GI, the fastest dose fall-off was noted in HA (3.35±0.64), followed by conventional Non-cop VMAT of (3.70±0.80), and conventional Cop VMAT of (4.90±1.85)(all P<0.05). For the brainstem sparing, HA plan performed better than Non-cop plan[(604.14±531.61) cGy vs.(682.75±558.22) cGy, P<0.05)]. For normal brain tissue sparing, HA approach showed significant reduction than conventional Cop and Non-cop VMAT (both P<0.05). For MU, HA approach (2 872.60 ± 566.93) was significantly lower than those of Non-cop VMAT (3 771.28 ± 1 022.38, P<0.05) and Cop VMAT (4 494.08 ± 1 323.09, P<0.05). In terms of plan complexity, the MCSv of Cop plan was the lowest, indicating that the complexity was the highest ( P<0.05). The AlPO of HA was significantly higher than that of Non-cop VMAT ( P<0.05), suggesting that the complexity of HA plan was lower ( P<0.05). Conclusion:For the treatment of brain metastases, HA provides better conformity, more rapid dose fall-off, better sparing of brainstem and normal brain tissues and less plan complexity compared with conventional VMAT.
RESUMEN
Objective:To compare the calculation result and analyzes the reasons for their differences so as to provide reference for the revision and improvement of the current national standards on radiation shielding design for the room of brachytherapy.Methods:For the initial activity 10 Ci (1 Ci=3.7×10 10 Bq) of radioactive sources, the shielding schemes of brachytherapy room were designed in accordance with UK Institnte of Physics and Engineering in Medicine(IPEM) Report 75, USA NCRP Report 151 and the national standard GBZ/T 201.3-2014, respectively. The differences in shielding limits, occupancy factors and other relevant factors are compared in detail. Results:The annual exposure time in a typical brachytherpy room was about 330 h. The point-specific concrete thickness were 70, 65, 61, 70, 50 cm as required by NCRP Report 151, 41, 43, 30, 40, 39 cm by IREM regulations and 84, 79, 46, 88, 39 cm by GBZ/T 201.3, respectively. The concerned concrete shielding thickness calculated under the GBZ/T 201.3-2014 was generally thicker, with lesser difference from NCRP Report 151 result, whereas that from the IPEM75 report was thinnest. The equivalent lead shielding thicknesses of the protective doors calculated using the three method are 1.170, 0.854 and 1.040 cm, respectively.Conclusions:The shielding thickness calculated using the calculation method and evaluation index recommended by the current Chinese shielding standards for brachytherapy bunker is similar to that reported in NCRP151, but is conservative. In particular, the evaluation index of instantaneous dose equivalent rate required by the current national standards and the relative conservative value of occupancy factor will significantly increase the shielding thickness required by the main shielding area.
RESUMEN
Objective:To discuss the design details of accelerator room for a novel enclosed O-ring linac Halcyon, and to optimize its protection and layout.Methods:According to the optimization principle of radiation protection and the requirements of national radiation protection standards, and the structural characteristics of Halcyon accelerator, the differences between conventional and this novel accelerator rooms were analyzed by discussing the space layout of the machine room, shielding calculation, electrical facilities, purifying ventilation, temperature and humidity control and other factors.Results:The Halcyon machine had a compact structure, a closed ring frame design and a main beam shielding device, which could greatly reduce the radiation protection pressure while improving the space utilization rate of the machine room. The optimized design layout of the machine room could eliminate hidden dangers, avoid design defects, and prevent adverse consequences caused by design errors.Conclusions:The overall structure of Halcyon accelerator is different from that of conventional accelerators. The design details should be taken into full consideration to ensure the optimization of radiation protection, lay a good foundation for subsequent installation, debugging and operation of the equipment and create a good treatment environment for patients and medical staff.
RESUMEN
BACKGROUND@#There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China. We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage I EC using in-house made multi-channel applicators (IH-MCA) in a single institution.@*METHODS@#Three hundred and ninety patients with stage I IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015. All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after external beam radiotherapy (EBRT). The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT. Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment. The Kaplan-Meier method was used to calculate survival rate.@*RESULTS@#Follow-up rate was 92.8% and the median follow-up time was 48 months (range 4-172 months). The 5-year overall survival (OS), progression-free survival, local recurrence, and distant metastasis rates for all patients were 96.3%, 92.1%, 2.9%, and 4.8% respectively. Two patients had isolated relapse in vagina outside the irradiated volume. The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio: 0.368, 95% confidence interval [CI]: 0.131-1.035, P = 0.048; hazard ratio: 0.576, 95% CI: 0.347-0.958, P = 0.026,).@*CONCLUSIONS@#For patients with IR to HR stage I EC, adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates. Age and grade were the prognostic factors correlated with OS.
RESUMEN
Objective To analyze the failure and processing methods of helical tomotherapy multileaf collimator (MLC) and summarize relevant maintenance experience,aiming to accurately identify the faulty parts,shorten the downtime and enhance the work time.Methods The failure data of the helical tomotherapy MLC system in the past 48 months were analyzed to identify the common faulty parts,causes and processing methods.Results During the previous 48 months,the MLC failure occurred for 20 times,11 times for air compressor failure,4 times for position verification board failure,twice for leaf driver failure,twice for cushion valve failure and once for the slip of leaf position verification rod.The MLC failure was significantly correlated with the humidity of high-pressure gas.The work time of machine exerted significant effect upon the service time of MLC parts.Conclusions The structure of the helical tomotherapy MLC system is complex.The high-intensity work increases the failure rate.The humidity of high-pressure gas affects the normal operation of the MLC equipment.The faulty parts can be identified,the downtime can be reduced and the work time can be enhanced by summarizing the experience of MLC maintenance.
RESUMEN
Background@#There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China. We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage I EC using in-house made multi-channel applicators (IH-MCA) in a single institution.@*Methods@#Three hundred and ninety patients with stage I IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015. All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after external beam radiotherapy (EBRT). The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT. Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment. The Kaplan-Meier method was used to calculate survival rate.@*Results@#Follow-up rate was 92.8% and the median follow-up time was 48 months (range 4–172 months). The 5-year overall survival (OS), progression-free survival, local recurrence, and distant metastasis rates for all patients were 96.3%, 92.1%, 2.9%, and 4.8% respectively. Two patients had isolated relapse in vagina outside the irradiated volume. The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio: 0.368, 95% confidence interval [CI]: 0.131–1.035, P = 0.048; hazard ratio: 0.576, 95% CI: 0.347–0.958, P = 0.026,).@*Conclusions@#For patients with IR to HR stage I EC, adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates. Age and grade were the prognostic factors correlated with OS.
RESUMEN
Objective To evaluate the anxiety and explore relevant risk factors in patients receiving radiotherapy and their relatives,aiming to provide evidence for improving the quality of life. Methods Before radiotherapy,the self-rating anxiety scale (SAS) was utilized to evaluate the anxiety of patients and their relatives. The incidence rate of anxiety was analyzed under the influence from different risk factors. Results A total of 646 participants (463 patients and 183 relatives) were included in this study. The average SAS scores of all participants,patients and family relatives were 41.52±10. 08,41.02±19. 37 and 42.79±11. 56, significantly higher than 37.23±12. 58 for the healthy population in China (P= 0. 000. 0.000,0. 000).For patients aged 11-30,31-50 and 51-90 years,the incidence rate of anxiety was 26％(7/ 26),11. 0％(20/ 182) and 19. 1％(47/ 246),respectively (P= 0. 026).The incidence rate of anxiety for patients with and without tumor recurrence was 27％ (13/ 48) and 15. 4％ (64/ 415) (P= 0. 040).Seventeen of 63 patients (27％) with metastases experienced anxiety,whereas 60 of 396 patients (15. 2％) without metastases suffered from anxiety (P= 0. 020).The incidence rate of anxiety in patients with three or more chronic diseases was 26％(19/ 74),significantly higher compared with 15. 0％(58/ 387) in those with less comorbidities (P= 0. 024). Multivariate binary logistic regression analysis demonstrated that three or more chronic diseases or serious diseases were high risk factors of anxiety (OR= 1. 92,95％CI:1. 03-3. 567). Conclusions Patients who receive radiotherapy and their relatives are prone to anxiety. Young age,tumor recurrence or metastasis and≥ three comorbidities or severe diseases are the high risk factors of anxiety. It is necessary to evaluate the anxiety of patients and their family relatives before radiotherapy and deliver psychological counseling.
RESUMEN
Objective To explore and establish accurate detection quality control method of source positioning and timer precision for afterloading equipment. Methods The source positioning detection device was made of hd camera,EBT3 disposable film and steel rule,collecting source in each resident point for video images and film. Accurate measurement of radioactive source positioning and timer accuracy, including the timing absolute error and linear error through analysis of image sampling rate. After the film grayscale distribution analysis,comparison between film gray peak position and the measurement of resident point geometry,got the stay point source physics and radiation center deviation. Results Radioactive source physics and radiation center deviation was (-0.33± 0. 10) mm;For all default dwell time,timer average absolute deviation was (0.22±0. 02) s,linear fitting result was y=x-0. 226,R2=1,timing linear error was-0. 01％ Conclusions established detection means through the video images and film exposure quantitative analysis for accurately determination of source positioning,dwell time and source radiation center precision. After experimental testing the machine precision satisfied the requirement of clinical use.
RESUMEN
Objective To compare metabolite ratios in the basal ganglia regions between preterm and term neonates and analyze the correlation between metabolite ratio and postmenstrual age(PMA)using 2D magnetic resonance spectroscopy(MRS)at 3.0T,so as to explore the value of MRS in evaluating neonatal brain development.Methods Normal neonates who underwent 3.0T MRS exam ination were recruited.Axial 2D MRS was performed with the point-resolved spectroscopy sequence(PRESS)(echo time/repetition time,144 ms/1 000 ms) through the basal ganglia covering three regions of interest(ROI)(i.e.bilateral lenticular nucleus,thalamus and white matter beside the anterior horn of lateral ventricle).The peak areas ratios of Cho/Cr,NAA/Cho and NAA/Cr were calculated.Metabolite ratios were compared between preterm and term neonates,and between three ROIs. Correlation between metabolite ratio and PMA was further analyzed.Results Totally 54 neonates were included(preterm/term,27/27).In all the three ROIs,preterm neonates presented significantly higher Cho/Cr(P＜0.05) and significantly lower NAA/Cho ratios(P＜0.001)than those of term neonates;higher NAA/Cr ratio was only observed in the lenticular nucleus of preterm neonates(P＜0.001).Significant differences in metabolite ratios were detected among the three ROIs in preterm group(P＜0.05).For term group,metabolite ratios differed between lenticular nucleus and white matter beside the anterior horn of the lateral ventricle(P＜0.01),while no difference between lenticular nucleus and thalamus was found(P＞0.05).Significant correlation between metabolite ratio and PMA was found in all the three ROIs except NAA/Cr ratio in the white matter beside the anterior horn of the lateral ventricle.To be specific,we found linear negative correlation of Cho/Cr ratio(r= -0.325,-0.633,-0.438) and positive correlation of NAA/Cho ratio(r = 0.604,0.773,0.483)in all the three ROIs,but negative correlations of NAA/Cr ratio(r=0.487,0.367)in lenticular nucleus and thalamus with PMA.Conclusion Our findings suggest the tempo-spatial pattern of neonatal brain metabolite development in terms of anatomic location and PMA.Besides,the multi-voxel MRS presents potentials in establishing the normal topologic and age-matched reference in neonates and thus making brain maturation assessment and detection of early abnormal metabolism.
RESUMEN
Objective To explore the significance of signal classification by multimodal magnetic resonance imaging(MRI)(including conventional MRI,diffusion imaging,and susceptibility-weighted imaging)on neonatal punctate white matter lesions(PWML).Methods Between March 2011 and February 2013,neonates with PWML who underwent 3.0T MRI examination were recruited.The routine protocols included T1 weighted imaging (T1WI),T2 weighted imaging(T2WI),diffusion tensor imaging(DTI),and 3D-enhanced susceptibility-weighted angiography(ESWAN).Apparent diffusion coefficient(ADC)map,magnitude image,and phase image were obtained from DTI and ESWAN,respectively.The signal of PWML was one-to-one observed on T1WI,T2WI, ADC map and magnitude image.The combined signals were classified and the number of cases of each type was counted.Results Totally 84 neonates with PWML were included(preterm/term,47/37).Seven signal types were found and classified into three groups: ① Type Ⅰ was the most,59 cases,accounting for 70.24%,with the performance of high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and high-signal intensity on magnitude image. ② Type Ⅱ,7 cases,accounting for 8.33%,high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and low-signal intensity on magnitude image.③ Type Ⅲ - Ⅶ,26 cases,accounting for 30.95%,high-signal intensity on T1WI,low/iso-signal intensity on T2WI,low/iso-signal intensity on ADC map,high/iso-signal intensity on magnitude image.There was no significant difference in the incidence of different signal types between preterm and full-term PWML neonates. Conclusion Magnetic resonance signal may reflect the characteristics of PWML lesions.Signal classification of PWML by multimodal magnetic resonance imaging is helpful in determining injury type and has certain significance in guiding clinical treatment.
RESUMEN
Objective:To conduct in-depth study of the distribution and diversity of viruses in poultry is of great importance in monitoring the emergence of interspecies transmission of novel viruses that may cause epidemics with public health significance. Poultry is an economically important source of meat, eggs and feathers which plays an important role as natural reservoirs of many pathogenic viruses. Compared with wild animals, poultry have more frequent interactions and therefore opportunities to transmit their viruses to human.Methods:To study the viromes of different types of poultry in Hainan, China, we used metagenomics for deep viral nucleic acid sequencing of the faecal samples collected from chickens, ducks and pigeons from a live poultry market in Haikou.Result:The poultry viromes were identified by sequence similarity comparisons of viral reads (BLASTxE score, <5) against viral reference database. A total of 15 309 viral reads were obtained, approximately 13 063, 1 370 and 876 viral reads were generated from the chicken, duck, pigeon faecal samples, respectively. The majority of the sequences were homologous to the animal virus of Adenoviridae, Herpeaviridae, Picobirnaviridae, Reoviridae, Retroviridae, Circoviridae, Paramyxoviridae, Astroviridae, Caliciviridae, Coronaviridae, Picornaviridae, and Orthomyxoviridae. The VP4 and VP7 segments of a pigeon rotavirus, similar to fox rotavirus in group A, were sequenced and phylogenetically analyzed. The near full genome of a pigeon circovirus was also analyzed.Conclusion:The major types of poultry in a Haikou harbor many different families of viruses in their feces which may have the potential for interspecies transmissions. Further studies should be conducted to identify the most prevalent and important viruses among a larger number of poultry in Haikou and other areas in Hainan.
RESUMEN
Objective To investigate the relationship of hypothyroxinemia to gestational diabetes mellitus during early pregnancy. Methods A total of 11 365 cases of women with early singleton pregnancies were collected from Chongqing Health Center for Women and Children. The screening of thyroid function was performed. The postload glucose concentrations and the risks of gestational diabetes mellitus in hypothyroxinemia were investigated. The relationship of thyroid hormones to postload glucose concentration was evaluated. The association between thyroid peroxidase antibodies(TPOAb) and gestational diabetes mellitus was analyzed. Results Early pregnancy women with hypothyroxinemia had a higher postload glucose concentration. Comparing to normal pregnancy women, the prevalence of gestational diabetes mellitus in hypothyroxinemia was higher(42.2%vs18.4%, P<0.05). Free thyroxine(FT4) was significantly negatively correlated with postload glucose concentration. FT4 was associated with gestational diabetes mellitus. The risk of gestational diabetes mellitus was greater when FT4 was lower. The prevalence of gestational diabetes mellitus in early pregnancy women with TPOAb levels ≥500 IU/ml was significantly higher than that in normal pregnancy women (31.2%vs 18.4%, P<0.05). Conclusion Early pregnancy women with hypothyroxinemia and TPOAb≥500 IU/ml were related to the risk of gestational diabetes mellitus. Lower FT4 was the risk factor of gestational diabetes mellitus.
RESUMEN
Objective To examine the interfractional dosimetric variations among inverse three-dimensional (3D) plan, forward 3D plan, and two-dimensional (2D) plan of intracavitary brachytherapy for cervical cancer, and to discuss the risk of implementing the interval plan on different implantation applicators at short time intervals.Methods Twenty-five groups of CT-guided intracavitary brachytherapy (two consecutive radiations at ≤4 d apart) plans from 11 cervical cancer patients who received radical radiation therapy in our hospital were reviewed and compared.The dwelling location and time of the first intracavitary brachytherapy plan (Plan-1) were simulated on the CT image of the second intracavitary brachytherapy to form Plan-1-S.The target coverage indices and D 2 cc of organs at risk (OARs) of Plan-1-S and Plan 2(actual plan of the second intracavitary brachytherapy) under the three planning modes were recorded and compared using the paired t-test, Wilcoxon signed rank test, and ANOVA.Results The D90, D100, and V100 of high-risk CTV were significantly lower in Plan-1-S created under the inverse mode in the actual plan (-9.11±13.46%,-13.16±18.79%, and-7.80±13.34%, P=0.002, 0.002, and 0.005, respectively).D90, D100, and V100 of the interval plan had the greatest reduction under the inverse mode (76%, 80%, and 76%, respectively).The maximum reductions in D90, D100, and V100 were 332.14 cGy (2D), 244.12 cGy (forward), and 41.76%(inverse).OAR overdose occurred most frequently under the forward mode;the rates of D90, D100, and V100 reductions accompanied by one OAR overdose were 29.41%, 37.50%, and 25.00%, and the rates of D90, D100, and V100 reductions by two OAR overdoses were 5.88%, 12.50%, and 6.25%,respectively.Overdose occurred most frequently in the small intestine (36%).Comparison of the three planning modes showed that the inverse plan had a greater reduction in each target coverage index than the 2D plan.Conclusions The simulated interval plan can significantly reduce target coverage and increase the risk of OAR overdose regardless of the planning mode and the short time intervals, and is therefore not recommended for clinical application.
RESUMEN
Objective To compare the relative dose of small fields measured by clinically common detectors and those obtained from Monte Carlo simulation in order to obtain the accurate measurement method, and to modify the inappropriate detectors.Methods The percentage depth-dose distribution curve and profile (flatness and symmetry) curves were collected at 2 cm×2 cm, 3 cm×3 cm, and 4 cm×4 cm under 6-MV X-ray of Trilogy linear accelerator by CC13, PFD, SFD, and blue phantom.The results were compared with the stimulation results from Monte Carlo method (the current gold standard).The correction factors for the detectors with large error were calculated to provide reference data for clinical practice.Results The results measured by SFD detector were most close to the results from Monte Carlo simulation.The measurement errors of CC13 and PFD detectors were large.The correction factor in the penumbra for CC13 and PFD detector was 0.664-1.499.Conclusions SFD detector is better than CC13 and PFD detector in the measurement of small fields, but CC13 and PFD detector can provide reference data for clinical practice after the corresponding correction.
RESUMEN
Objective To investigate how to use the ArcCHECK to complete synchronization test in helical tomotherapy(HT). Methods According to the synchronization test suggested by AAPM TG148, three aspects should be tested.(1)Gantry angle consistency:ArcCHECK device in the long axis was perpendicular to the rotation plane using virtual isocenter positioning. A delivery sequence was defined with a slice width of 2.5 cm,a pitch of 0.1,and a minimum of 40 rotations. The control sinogram was set to open the middle two leaves(No. 32 and 33)at projections centered at 0°, 120°, and 240°.(2)Couch speed uniformity:The ArcCHECK was fixed on the treatment couch by positioning the long axis in the movement direction of couch. An irradiation was done with a static gantry in the 0° position, the collimation set to 1 cm,and all MLC leaves open. A couch travel distance of 20 cm was programmed using a clinically common couch speed(0.3-0.5 mm/s for 2.5 cm treatment slice width)in the course of irradiation.(3) Synchronization of couch translation and gantry rotation:In this test,a rotational irradiation was used with the nominal 1.0 cm beam and a pitch of 1 for 13 rotations. The control sonogram was set to open all the leaves for a half rotation on the second,seventh,and twelfth rotations. The initial collected data were used as the baseline data of parameters. The subsequent measurements were compared with the baseline data using the point to point absolute dose pass rates of DD(dose difference,1%). Results The gantry angle consistency could check the correct initial angles at the beginning of the treatment and the ability to reproduce the projection every rotation.There were six parallel and straight high-dose regions in ArcCHECK software.In the couch speed uniformity test,the relative dose in the long axis in the high-dose regions was changed less than 2%. In the synchronization test of couch translation and gantry rotation,three parallel high-dose regions with the same separation spacing were present in the ArcCHECK software. The synchronization tests were done twenty-eight times in the second,seventh, and twelfth irradiation rotations and the average pass rates were 93.2%±1.5%,93.7%±1.1%,and 93.5%±1.3%,respectively. Conclusions The ArcCHECK device is a suitable alternative method for performing the synchronization test in HT due to its lower workload and costs compared with the film.
RESUMEN
Objective To investigate the surgical methods and experience of laparoscopic radical cystectomy and orthotopic ileal neobladder for invasive bladder cancer. Methods The clinical data of 14 patients with invasive bladder cancer underwent laparoscopic radical cystectomy and orthotopic ileal neobladder were collected retrospectively during March 2011 and October 2014. Results The 13 patients with invasive bladder cancer were successfully completed laparoscopic radical cystectomy and orthotopic ileal neobladder. 1 case was treated with laparotomy because of unsatisfactory surgery ifeld caused by excessive tumor bleeding. Twelve cases of the urethra-neobaldder anastomosis were completed through the abdominal incision, while for the other 2 cases, the anastomosis was done under the laparoscope, 2 cases were performed neovesicourethral anastomosis using single-needle running sutures through laparoscopy. The median operative time was 444 minutes, the mean intraoperative blood loss was 490 ml. Postoperative pathologic results conifrmed that 12 cases were bladder transitional cell carcinoma (1 case with partial squamous cell carcinoma) and 2 cases with bladder adenocarcinoma. No severe complication occurred except for 2 cases of urinary leakage and 1 case of urinary incontinence. Patients were followed up for 6-56 months,within which 3 patients were died of distant metastasis, 1 case was detected with intracranial metastasis, 1 case was found with urethra-vesical anastomotic stenosis while cured after urethrotomy. Ten cases were well recovered and the mean volume of the neobladder was 300 ml. Conclusions Laparoscopic radical cystectomy and orthotopic ileal neobladder have the advantage of better therapeutic effects, safety, minimal invasion and rapid recovery, which are the preferred therapeutic methods for invasive bladder cancer.