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Objective:To design and implement a plan data archiving system (PDAS) for radiotherapy treatment, in order to improve the efficiency of plan archiving and avoid plan data loss.Methods:The original plan file in the treatment planning system (TPS) was read and parsed, and the record and verification (R&V) system database was accessed to obtain the patient′s treatment record. PDAS processed all parameters involved in the plan archiving and saved the structured data into a local database. PDAS included two major modules, the plan archiving module and the plan loss detection module. The former could be divided into four parts, data sorting, data compression, archiving check and plan recovery. For different modules, we designed corresponding logic rules and wrote programs to realize the system. Compared with the plan data of manual archiving, the clinical application effect of PDAS was evaluated.Results:Each module of PDAS was developed and implemented. During 31 months of clinical application, the system was stable, and 17 614 plans were archived. Compared with manual archiving, PDAS improved the archiving efficiency significantly and reduced the plan loss rate from 0.004 or so to 0.Conclusions:PDAS can improve the efficiency of plan archiving and ensure the security and integrity of plan data.
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Objective To evaluate the dosimetric penumbra and delivery accuracy of dynamic jaw delivery in tomotberapy.Methods The jaw positioning hardware and the beam model were updated.Mechanical alignments were verified after the upgrade of the jaw positioning hardware.PDDs and beam profiles were measured by a two-dimensional water tank and compared with the new beam model.Dose penumbras in the longitudinal direction were compared between the dynamic and fixed jaw plans for different field width.Delivery accuracy was evaluated by point dose measurements with A1SL chamber and gamma analysis on the dose distribution measured by ArcCheck detector array.Results Mechanical alignments were in tolerance and beam characteristics were tuned to match the dynamic jaw beam model.Differences in the field width between the measured results and reference data were ＜ 0.3％ for both symmetric and asymmetric profiles in the longitudinal direction.The dose penumbra in dynamic jaw delivery was reduced from 17.92 mm to 7.51 mm for 2.5 cm jaw,and from 33.73 mm to 6.97 mm for 5.0 cm jaw,close to the penumbra of the traditional 1.0 cm jaw.IMRT verification of clinical cases was performed by A1SL ion chamber and ArcCheck detector array.The mean point dose difference was 0.33％ ± 0.73％ between the calculated and meassured data.Gamma analysis of dose distributions revealed that approximately 99.8％ of the points satisfied the gamma criteria of 3％ dose difference and 3 mm distance-to-agreement and the mean passing rates remained 97.9％ even with tightest criteria of 2％/2 mm,and 100.0％ with the criteria of 4％/4 mm,respectively.Conclusions Dosimetric penumbra in the longitudinal direction is significantly improved by the dynamic jaw delivery.Both the mechanical alignment and treatment delivery are qualified,suggesting that this new treatment is accurate and reliable.
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Objective To evaluate the feasibility of replacing the fixed jaw 2.5 cm mode with dynamic jaw 5.0 cm for mid-esophageal cancer after the upgrade of helical tomotherapy (TOMO).Methods A total of 10 patients with locally advanced esophageal cancer were planned with radical intent using 2.5 cm fixed jaw (FJ2.5),2.5 cm dynamic jaw (DJ2.5) and 5.0 cm dynamic jaw (DJ 5.0) modes respectively on TOMO.Dose conformity index (CI),dose homogeneity index (HI) and dose to OARs were analyzed to evaluate the plan quality.Treatment time and monitor units were used to assess efficiency.Results CI and HI met clinical requirement for all plans.D J5.0 plans showed significant improvement over FJ2.5 plans in terms of V5 and mean dose to lungs,the V5,V10 and mean dose to normal tissues (t =9.751,4.163,11.840,10.321,3.745,P＜0.05).DJ2.5 plans were superior to DJ5.0 plans in the aspects of the V30,V40 and mean dose to heart,the V20 and mean dose to normal tissues (-2.454,-3.275,-4.192,-6.435,-4.139,-6.431,P＜0.05).Compared with DJ2.5 plans,the V5,V20,V30 and mean dose to lungs,the V4 0and mean dose to heart,maximum dose to cord and cord PRV,the V5,V10,V20 and mean dose to normal tissues of FJ2.5 plans were worse (t=8.289,6.142,3.137,8.895,3.597,4.565,3.782,5.429,16.421,12.496,8.286,11.933,P＜0.05).The beam-on time of DJ5.0 plans was significantly reduced by 43.9％ and 42.8％ compared with FJ2.5 and DJ2.5 plans respectively,and the machine monitor unit was reduced by 42.8％ and 43.8％ respectively.Conclusions The dynamic jaw of 5.0 cm technique is recommended for treatment of mid-esophageal cancer for sake of plan quality and efficiency.It does not only shorten the treatment time and improve radiation efficiency compared with fixed and dynamic jaw of 2.5 cm technique,but also provides a dosimetric advantage in terms of lung and normal tissue sparing in comparison with fixed jaw of 2.5 cm.When only improving plan quality is concerned,the dynamic jaw of 2.5 cm technique is more recommendable.
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Radiotherapy is an important treatment for lung cancer. However,the radiation-induced lung injury(RILI)affects some patients and also affects the efficacy of treatment. Therefore,it is very important to identify high-risk patients who may have RI-LI and take action intervention or monitoring. Although the individual difference is often explained by clinical and dosimetric,genetic factors also influence the occurrence of RILI. Currently,there are reports on the relationship between single nucleotide polymorphism (SNP)and RILI. The SNP of these specific genes may become an important predictor of RILI,and thus reduce the incidence of radia-tion-induced lung injury.
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Objective To evaluate the effect of the tolerance table of different couch positions in the record and verify system (R&V system) upon the setup accuracy.Methods Clinical data of 715 patients (15 743 fractions of treatment) were extracted from the R&V system database and assigned into four categories including thorax and abdomen,head and neck,breast,and rectum based on the disease site and immobilization device.The first day couch position (FstD) and cumulative average couch position (CumA)were utilized as the references to analyze the couch setup of each faction of treatment,and to establish the tolerance tables of different sites.The sensitivity and specificity of two methods were evaluated by the actual clinical treatment record of the patients.Results For the FstD as the reference,the couch tolerance in the breast was significantly higher than those in other parts.When the CumA was used as the reference,the couch tolerance tended to be stable after a certain fractions of treatment,and the tolerance of all sites was less than that of the FstD.The tolerance tables significantly differed between these two methods (P=0.000).Both two methods possessed high specificity,whereas the CumA method yielded higher sensitivity than the FstD approach.Conclusion Setting a reasonable tolerance table of couch position can effectively improve the setup accuracy.
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Objective To evaluate the value of color Doppler two-dimensional ultrasound combined with real-time ultrasonic shear wave elastography (SWE) in the early diagnosis of breast cancer.Methods A total of 110 suspected breast tumor patients from October 2015 to April 2017 were selected as subjects.Comprehensive detailed examinations on the patients were conducted by routine two-dimensional ultrasound,color Doppler and SWE,and the lesion location,size,boundary,capsule,internal echo,blood flow,elastic value and other related data were recorded.The BI-RADS classification was conducted based on these data.Pathological diagnosis was used as the gold standard to compare the diagnostic effects of color Doppler two-dimensional ultrasound and the combination of color Doppler two-dimensional ultrasound and SWE.Results Of the 110 patients,78 were malignant and 32 were benign.The sensitivity of color Doppler two-dimensional ultrasound for breast cancer diagnosis was 83.3％,the specificity was 81.2％,and the accuracy was 82.7％.The sensitivity of color Doppler two-dimensional ultrasound combined with SWE for breast cancer diagnosis was 88.5％,the specificity was 90.6％,and the accuracy was 94.5％.Conclusion Color Doppler two-dimensional ultrasound combined with SWE can complement each other and improve the qualitative and quantitative diagnosis of early breast cancer.
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Limonene (C₁₀H₁₆) and bisabolene (C₁₅H₂₄) are both naturally occurring terpenes in plants. Depending on the number of C₅ units, limonene and bisabolene are recognized as representative monoterpenes and sesquiterpenes, respectively. Limonene and bisabolene are important pharmaceutical and nutraceutical products used in the prevention and treatment of cancer and many other diseases. In addition, they can be used as starting materials to produce a range of commercially valuable products, such as pharmaceuticals, nutraceuticals, cosmetics, and biofuels. The low abundance or yield of limonene and bisabolene in plants renders their isolation from plant sources non-economically viable. Isolation of limonene and bisabolene from plants also suffers from low efficiency and often requires harsh reaction conditions, prolonged reaction times, and expensive equipment cost. Recently, the rapid developments in metabolic engineering of microbes provide a promising alternative route for producing these plant natural products. Therefore, producing limonene and bisabolene by engineering microbial cells into microbial factories is becoming an attractive alternative approach that can overcome the bottlenecks, making it more sustainable, environmentally friendly and economically competitive. Here, we reviewed the status of metabolic engineering of microbes that produce limonene and bisabolene including microbial hosts, key enzymes, metabolic pathways and engineering of limonene/bisabolene biosynthesis. Furthermore, key challenges and future perspectives were discussed.
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Objective To use clustering analysis to help physicians detect abnormal parameters in radiotherapy treatment plans and improve the efficiency of plan verification. Methods From 2010 to 2015, 835 breast cancer treatment plans for using 4?field hybrid intensity?modulated radiotherapy from MOSAIQ were collectted. Fractional dose, beam angle, and monitor unit were used as featured parameters of a treatment plan to generate a dataset. The K?means clustering algorithm based on principal component analysis was used to perform a clustering analysis of the dataset and divide the dataset into different clusters. The outliers of clusters were automatically detected based on the distance threshold. The outlier?contained treatment plans were manually verified by physicians to determine the accuracy of clustering analysis in detection of abnormal plans. Results In the clustering analysis, the sample space composed by parameters of treatment plans for breast cancer was divided into 4 clusters, 3 of which had outliers detected. In the targeted treatment plans, 3 plans became outliers because of special target volume and the other 4 plans needed improvement. Conclusions Clustering analysis is effective to help physicians to independently verify treatment plans.
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Objective To investigate the effects of different irradiation techniques on dose distribution in target volume and normal tissues after the radical surgery for gastroesophageal junction adenocarcinoma,and to provide the optimal regimen for clinical treatment.Methods A total of 9 patients with gastroesophageal junction adenocarcinoma who underwent radical esophagus-proximal gastrectomy or total gastrectomy were enrolled.The therapeutic regimens of five-field static intensity-modulated radiotherapy (IMRT),volumetric-modulated arc therapy (VMAT),and helical tomotherapy (HT) were designed for each patient,and the dose-volume histogram was used to evaluate the effects of different irradiation techniques on the conformity index (CI) and homogeneity index (HI) of target volume and the surrounding normal tissues. The prescribed dose was 45 Gy at 1.8 Gy/fraction.The patients received oral S-1 as concurrent chemotherapy at a dose of 80 mg/(m 2? d) twice a day during radiotherapy.Results Compared with IMRT and VMAT,HT had better CI and HI of the target volume,as well as a better protective effect on the intestinal tract and bone marrow.Compared with IMRT and HT,VMAT had a lower V20 and V30 for the left kidney and a lower V30 for the heart,while IMRT had lower V5 and V10 for both lungs;V20 and mean dose showed no significant differences between the three techniques.HT had the highest mean sub-field hop count,followed by IMRT and VMAT.Conclusions IMRT, VMAT, and HT can meet the clinical requirements,but besides ensuring the best CI and HI of the target volume,HT has a good protective effect on the intestine and spinal cord and can help to reduce the incidence of adverse events in patients.
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Objective To preliminarily observe the clinical efficacy of hippocampal-sparing prophylactic cranial irradiation (HS-PCI) using helical tomotherapy (HT) in patients with limited-stage small-cell lung cancer (LS-SCLC) after chemoradiotherapy,and compare HT with intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in dose distribution.Methods From April to June,2014,six patients with LS-SCLC who had achieved a complete remission after chemoradiotherapy were assigned to HS-PCI using HT within a month after brain metastasis was ruled out using brain magnetic resonance imaging (MRI).After fusing CT images and MRI images,the hippocampus was contoured in the fusion images and hippocampal avoidance regions were created using a volumetric expansion of 3 mm around the hippocampus.A dose of 25 Gy in 10 fractions to 95％ of planning target volume (PTV) was prescribed in HT,IMRT,and VMAT.The clinical efficacy,adverse reactions,neurocognitive function,and brain metastasis were evaluated for HT.The dose distribution in PTV and hippocampus were compared between HT,IMRT,and VMAT.Results There were one patient with abdominal wall and abdominal lymph node metastases,one patient with local recurrence,and no patient with brain metastasis during the observation period.The numbers of patients with grade 1 and grade 2 headache,dizziness,and hair loss reactions were 3 and 1,3 and 1,and 4 and 2,respectively.There were no significant differences in the average score of the Mini-Mental State Examination before treatment and at 3 and 6 months after treatment (29.7,29.2,and 29.3 ; P =0.083,0.317,and 0.157).The mean dose to the hippocampus was 16.85 Gy for IMRT and 17.59 Gy for VMAT.For HT,the mean doses to the hippocampus and avoidance regions were reduced to 5.26 Gy and 6.21 Gy,respectively.The prescribed dose for HT was reduced by 79％ and 71％ compared with IMRT and VMAT,respectively.The average coverage rate of the prescribed dose was 94.48％ for HT.Conclusions HT achieves promising dose distribution and target coverage in sparing of the hippocampus.Moreover,HT dose not increase the incidence of adverse reactions.The change in neurocognitive function needs to be further studied with longterm observation and large-scale sampling.
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<p><b>OBJECTIVE</b>To explore the correlation of the position and height of the examination couch with the accuracy of image registration in an exact effective field of vision (FOV) of single photon emission computed tomography/computed tomography (SPECT/CT) and determine the optimal position of the examination couch for best image registration.</p><p><b>METHODS</b>The tests were performed on a SPECT/CT with 6 radioactive (153)Gd sources in 3 groups (two in each group with energy peak of 40.9 Kev, 41.54 Kev, and 103.18 Kev) in an assorted standard pattern. Thirteen groups of slice data were obtained by changing the position and height of the bed but keeping the tomograpy slice constant. The bias of the accuracy of image registration was acquired using ALIGNMENT software and compared for different examination couch positions and heights.</p><p><b>RESULTS</b>The position of the examination couch at 0 cm in the Z axis and -4 cm in the Y axis showed the least error of image registration.</p><p><b>CONCLUSION</b>To achieve optimal SPECT and CT image fusion, quality control must be implemented and calibration of image registration accuracy should be done when necessary.</p>
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Humans , Algorithms , Image Enhancement , Patient Positioning , Software , Tomography, Emission-Computed, Single-PhotonABSTRACT
Objective To verify the dose delivery accuracy of volumetric-modulated arc therapy plan by log-file analysis of linear accelerator that can be created when a dynamic delivery occurs.Methods Accelerator log file in binary format recorded the accelerator execution plan for each control point corresponding to the gantry angle,multi-leaf collimator leave position,cumulative machine monitor units ( MU).These information were read from the accelerator log file with Matlab7.1,then the original control points in the plan file replaced the corresponding information for the log,which generated a new plan.New plan was exported into the planning system to reculculate the dose.The volume dose histogram (DVH) and dose distribution was contrasted to determine the accuracy of the accelerator plan of implementation between two plans.Results Compared with the original plan,antry angle difference over ± 1° accounted for about 35％ of the entire arc of control points in 4 of 12 arcs and the percentage of the leave error of ±0.5 mm was about 95％.MU error of a single control point was larger,but the cumulative MU for each are was small which was located between-0.09％ to 0.11％ in the selected 12 arcs.Between the targets,the maximum dose,minimum dose,the mean dose differences were from-0.07％ to 0.42％,-0.38％ to 0.40％,0.03％ to 0.08％,respectively.The maximum dose and mean dose differences of organs at risks were located from-1.16％ to 2.51％,-1.21％ to 3.12％,respectively.Conclusions Accelerator log-file analysis to verify the VMAT plan nan be supplyed to the experimental method supplement.
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Objective To explore the influence of computed tomography (CT) and magnetic resonance imaging (MRI) fusing technique on target volume and dosimetrics of normal tissues in intensity modulated radiotherapy (IMRT) for prostate carcinoma.Methods Ten patients with pathologically diagnosed moderate-high risk localized prostate carcinoma were enrolled in this study.CT and MRI images were collected.Same image slices of the prostate, seminal vesicles, rectum and bladder were anatomically delineated using image fusing software.Clinical target volume (CTV) was defined as the prostate plus seminal vesicles.IMRT treatment planning was designed basing on CT and MRI images, respectively.Differences of CTV volume and dose volume histogram of rectum and bladder between the two image groups were analyzed.Results The mean volume of CTV on CT and MRI images was 84.03 cm3 and 53.53 cm3,respectively (t =2.47,P=0.024).The V50, V60 and V70 of rectum were 30.28%, 19.13%, 9.53% on MRI and 37.03%, 24.99% and 14.55% on CT images, respectively, with significent difference (t =2.71,P=0.014 for V50; t =2.83,P=0.011 for V60; t=3.19,P=0.005 for V70).The maximal dose of bladder was 81.10 Gy on MRI and 82.45 Gy on CT, respectively(t=2.41,P=0.027).Conclusions By using image fusing technique, the mean volume of the prostate plus seminal vesicles delineated on MRI image is smaller as compared to CT image.The volume of the rectum receiving high irradiation dose can be reduced when MRI was used to delineate CTV compared to CT image.
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Brachytherapy has become an important treatment for soft tissue sarcoma by its unique radio-biology and radiation physics characteristics, the treatment time is divided in accordance with preoperative brachytherapy, intraoperative brachytherapy, postoperative brachytherapy, brachytherapy alone, which in im-proving the rate of limb preservation and local control rate sarcoma has played an important role. However, the timing of treatment, treatment modalities, the choice of implantation dose is still in dispute.