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1.
Krzysztof Slosarek Marta Szlag Barbara Bekman Aleksandra Grzadziel 《Reports of Practical Oncology and Radiotherapy》2010,15(1):8-14
Aim
The aim of the study was to estimate the dose at the reference point applying an aSi-EPID device in the course of patient treatment.Materials and methods
The method assumes direct proportionality between EPID signal and dose delivered to the patient reference point during the treatment session. The procedure consists of treatment plan calculation for the actual patient in the arc technique. The plan was realized with an elliptic water-equivalent phantom. An ionization chamber inside the phantom measured the dose delivered to the reference point. Simultaneously, the EPID matrix measured the CU distribution. EPID signal was also registered during patient irradiation with the same treatment plan. The formula for in vivo dose calculation was based on the CU(g) function, EPID signal registered during therapy and the relation between the dose and EPID signal level measured for the phantom. In vivo dose was compared with dose planned with the treatment planning system.Irradiation was performed with a Clinac accelerator by Varian Medical Systems in the RapidArc technique. The Clinac was equipped with an EPID matrix (electronic portal image device) of aSi-1000. Treatment plans were calculated with the Eclipse/Helios system. The phantom was a Scanditronix/Wellhöfer Slab phantom, and the ionization chamber was a 0.6 ccm PTW chamber.Results
In vivo dose calculations were performed for five patients. Planned dose at the reference point was 2 Gy for each treatment plan. Mean in vivo dose was in the range of 1.96–2.09.Conclusions
Our method was shown to be appropriate for in vivo dose evaluation in the RapidArc technique. 相似文献2.
Antonella Fogliata Giorgia Nicolini Celine Bourgier Alessandro Clivio Fiorenza De Rose Pascal Fenoglietto Francesca Lobefalo Pietro Mancosu Stefano Tomatis Eugenio Vanetti Marta Scorsetti Luca Cozzi 《PloS one》2015,10(12)
Purpose
To evaluate the performance of a model-based optimisation process for volumetric modulated arc therapy, VMAT, applied to whole breast irradiation.Methods and Materials
A set of 150 VMAT dose plans with simultaneous integrated boost were selected to train a model for the prediction of dose-volume constraints. The dosimetric validation was done on different groups of patients from three institutes for single (50 cases) and bilateral breast (20 cases).Results
Quantitative improvements were observed between the model-based and the reference plans, particularly for heart dose. Of 460 analysed dose-volume objectives, 13% of the clinical plans failed to meet the constraints while the respective model-based plans succeeded. Only in 5 cases did the reference plans pass while the respective model-based failed the criteria. For the bilateral breast analysis, the model-based plans resulted in superior or equivalent dose distributions to the reference plans in 96% of the cases.Conclusions
Plans optimised using a knowledge-based model to determine the dose-volume constraints showed dosimetric improvements when compared to earlier approved clinical plans. The model was applicable to patients from different centres for both single and bilateral breast irradiation. The data suggests that the dose-volume constraint optimisation can be effectively automated with the new engine and could encourage its application to clinical practice. 相似文献3.
T. ten Cate M. van Wely H. Gehlmann M. Mauti C. Camaro N. Reifart H. Suryapranata M.J. de Boer 《Netherlands heart journal》2015,23(11):525-530
Aims
The consequences of high radiation dose for patient and staff demand constant improvements in X-ray dose reduction technology. This study assessed non-inferiority of image quality and quantified patient dose reduction in interventional cardiology for an anatomy-specific optimised cine acquisition chain combined with advanced real-time image noise reduction algorithms referred to as ‘study cine’, compared with conventional angiography.Methods
Fifty patients underwent two coronary angiographic acquisitions: one with advanced image processing and optimised exposure system settings to enable dose reduction (study cine) and one with standard image processing and exposure settings (reference cine). The image sets of 39 patients (18 females, 21 males) were rated by six experienced independent reviewers, blinded to the patient and image characteristics. The image pairs were randomly presented. Overall 85 % of the study cine images were rated as better or equal quality compared with the reference cine (95 % CI 0.81–0.90). The median dose area product per frame decreased from 55 to 26 mGy.cm2/frame (53 % reduction, p < 0.001).Conclusion
This study demonstrates that the novel X-ray imaging technology provides non-inferior image quality compared with conventional angiographic systems for interventional cardiology with a 53 % patient dose reduction. 相似文献4.
Purpose
To determine whether negative associations between enrollment in a high-deductible health plan (HDHP) and one exemplar unhealthy behavior – daily smoking – are found only among people who chose these plans.Design
Cross-sectional analysis of nationally-representative data.Setting
United States from 2007 to 2008.Subjects
6,941 privately insured non-elderly adult participants in the 2007 Health Tracking Household Survey.Measures
Self-reported smoking status.Analysis
We classified subjects as HDHP or traditional health plan enrollees with employer-sponsored insurance (ESI) and no choice of plans, ESI with a choice of plans, or coverage through the non-group market. We used multivariate logistic regression to measure associations between HDHP enrollment and daily smoking within each of the 3 coverage source groups while controlling for potential confounders.Results
HDHP enrollment was associated with lower odds of smoking among individuals with ESI and a choice of plans (AOR 0.55, 95% CI 0.33–0.90) and those with non-group coverage (AOR 0.64, 95% CI 0.34–1.22), though the latter association was not statistically significant. HDHP enrollment was not associated with lower odds of smoking among individuals with ESI and no choice of plans (AOR 1.04, 95% CI 0.69–1.56).Conclusions
HDHP enrollment is associated with lower odds of smoking only among individuals who chose to enroll in an HDHP. Lower rates of unhealthy behaviors among HDHP enrollees may be a reflection of individuals who choose these plans. 相似文献5.
Karthikeyan Nithiyanantham Ganesh Kadirampatti Mani Vikraman Subramani Karrthick Karukkupalayam Palaniappan Mohanraj Uthiran Sennniandavar Vellengiri Sambasivaselli Raju Sanjay S. Supe Tejinder Kataria 《Reports of Practical Oncology and Radiotherapy》2014,19(5):287-295
Aim
To study the influence of segment width on plan quality for volumetric modulated arc based stereotactic body radiotherapy.Background
The redundancy of modulation for regularly shaped small volume tumors results in creation of many small segments and an increase of monitor units, with a consequent prolongation of treatment and uncertainty in treatment delivery.Materials and methods
Six cases each in lung, abdomen and liver were taken for the study. For each case, three VMAT SBRT plans were generated with different penalties on minimum segment width of 0.5, 1.0 and 1.5 cm. A comparison was made on the metrics of dose volume histogram, dosimetric indices, monitor units (MUs) and delivery accuracy.Results
The mean reduction of total MUs when compared with 0.5 cm plan was observed as 12.7 ± 6.0% and 17.5 ± 7.2% for 1.0 cm and 1.5 cm of minimum segment width, respectively. The p value showed a significant degradation in dosimetric indices for 1.5 cm plans when compared with 0.5 cm and 1.0 cm plans. The average deviation of measured dose with TPS calculated was 3.0 ± 1.1%, 2.1 ± 0.84% and 1.8 ± 0.9% for 0.5, 1.0 and 1.5 cm, respectively. The calculated gamma index with pass criteria of 2% dose difference and 2 mm distance to agreement was 95.9 ± 2.8%, 96.5 ± 2.6% and 97.8 ± 1.6% as calculated for 0.5, 1.0 and 1.5 cm of penalties, respectively. In view of the trade off between delivery efficiency and plan quality, 1 cm minimum segment width plans showed an improvement.Conclusions
VMAT SBRT plans with increased optimal value of minimum segment width showed better plan quality and delivery efficiency for stereotactic body radiotherapy. 相似文献6.
Marta Krystyna Gizynska Anna Zawadzka Wojciech Bulski 《Reports of Practical Oncology and Radiotherapy》2010,15(6):155-160
Aim
The purpose of this study was to examine the usefulness of using Simultaneous Integrated Boost (SIB) radiotherapy for thyroid cancer treatment.Background
At our hospital a 3D Conformal RadioTherapy (3D-CRT) technique involving photon and electron beams for the treatment of thyroid cancer was often used.1 High dose to the spinal canal was limiting the total dose of such a treatment. After investigation of Intensity Modulated Radiotherapy (IMRT) technique involving seven photon beams for first course of treatment3 we decided to examine possibility of reducing treatment fractions by using SIB radiotherapy.Material and methods
Plans for 10 patients were studied. For each patient, IMRT plan for the first course of treatment (50 Gy for PTV), two plans for the second course of treatment (10 Gy for BOOST) and a SIB plan (50 Gy for PTV, 56 Gy for BOOST) were prepared. For all plans, comparisons of dose statistics for the PTV, BOOST, PTV without BOOST (defined as PTV without BOOST with 1 cm margin), spinal canal and Patient Outline (Body) was done.Results
Minimum dose for BOOST is higher in the SIB technique than in the two course treatment. PTV without BOOST receives the same average dose in SIB and the 1st course IMRT – 50.10 Gy and 49.84 Gy, respectively. In the SIB technique, higher reduction of dose delivered to the spinal canal is possible (27 Gy compared with 30 Gy).Conclusion
SIB therapy for thyroid cancer with relation to typical two course treatment is a good proposal of reducing the number of fractions with the same dose for BOOST and PTV without BOOST. Additionally, better sparing of the spinal canal is achieved. 相似文献7.
Thomas M. Kessler Livio Mordasini Christian Weisstanner Peter Jüni Bruno R. da Costa Roland Wiest George N. Thalmann 《PloS one》2014,9(12)
Objective
To assess the efficacy and safety of sono-electro-magnetic therapy compared to placebo in men with refractory CPPS.Patients and Methods
In a randomized, placebo-controlled, double-blind single center trial, we assessed the effect of sono-electro-magnetic therapy in men with treatment refractory CPPS. Sixty male patients were randomly assigned to treatment with either sono-electro-magnetic (n = 30) or placebo therapy (n = 30) for 12 weeks. The primary outcome was a change in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) from baseline to 12 weeks.Results
The 12-week difference between sono-electro-magnetic and placebo therapy in changes of the NIH-CPSI total score was −3.1 points (95% CI −6.8 to 0.6, p = 0.11). In secondary comparisons of NIH-CPSI sub-scores, we found differences between groups most pronounced for the quality-of-life sub-score (difference at 12 weeks −1.6, 95% CI −2.8 to −0.4, p = 0.015). In stratified analyses, the benefit of sono-electro-magnetic therapy appeared more pronounced among patients who had a symptom duration of 12 months or less (difference in NIH-CPSI total score −8.3, 95% CI −14.5 to 2.6) than in patients with a longer symptom duration (−0.8, 95% CI −4.6 to 3.1; p for interaction = 0.023).Conclusions
Sono-electro-magnetic therapy did not result in a significant improvement of symptoms in the overall cohort of treatment refractory CPPS patients compared to placebo treatment. Subgroup analysis indicates, however, that patients with a symptom-duration of 12 months or less may benefit from sono-electro-magnetic therapy, warranting larger randomized controlled trials in this subpopulation.Trial Registration
ClinicalTrials.gov NCT00688506相似文献8.
Effie Viguiliouk Cyril W. C. Kendall Sonia Blanco Mejia Adrian I. Cozma Vanessa Ha Arash Mirrahimi Viranda H. Jayalath Livia S. A. Augustin Laura Chiavaroli Lawrence A. Leiter Russell J. de Souza David J. A. Jenkins John L. Sievenpiper 《PloS one》2014,9(7)
Background
Tree nut consumption has been associated with reduced diabetes risk, however, results from randomized trials on glycemic control have been inconsistent.Objective
To provide better evidence for diabetes guidelines development, we conducted a systematic review and meta-analysis of randomized controlled trials to assess the effects of tree nuts on markers of glycemic control in individuals with diabetes.Data Sources
MEDLINE, EMBASE, CINAHL, and Cochrane databases through 6 April 2014.Study Selection
Randomized controlled trials ≥3 weeks conducted in individuals with diabetes that compare the effect of diets emphasizing tree nuts to isocaloric diets without tree nuts on HbA1c, fasting glucose, fasting insulin, and HOMA-IR.Data Extraction and Synthesis
Two independent reviewer’s extracted relevant data and assessed study quality and risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences (MD) with 95% CI’s. Heterogeneity was assessed (Cochran Q-statistic) and quantified (I2).Results
Twelve trials (n = 450) were included. Diets emphasizing tree nuts at a median dose of 56 g/d significantly lowered HbA1c (MD = −0.07% [95% CI:−0.10, −0.03%]; P = 0.0003) and fasting glucose (MD = −0.15 mmol/L [95% CI: −0.27, −0.02 mmol/L]; P = 0.03) compared with control diets. No significant treatment effects were observed for fasting insulin and HOMA-IR, however the direction of effect favoured tree nuts.Limitations
Majority of trials were of short duration and poor quality.Conclusions
Pooled analyses show that tree nuts improve glycemic control in individuals with type 2 diabetes, supporting their inclusion in a healthy diet. Owing to the uncertainties in our analyses there is a need for longer, higher quality trials with a focus on using nuts to displace high-glycemic index carbohydrates.Trial Registration
ClinicalTrials.gov NCT01630980相似文献9.
Jia-Yang Lu Michael Lok-Man Cheung Bao-Tian Huang Li-Li Wu Wen-Jia Xie Zhi-Jian Chen De-Rui Li Liang-Xi Xie 《PloS one》2015,10(3)
Purpose
To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer.Methods
For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans.Results
The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1–3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found.Conclusion
The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs. 相似文献10.
Charles Mayo Luis Fong de los Santos Jon Kruse Charles R. Blackwell Luke B. McLemore Deanna Pafundi Joshua Stoker Michael Herman 《PloS one》2013,8(3)
Introduction
Results of use of methodology for VMAT commissioning and quality assurance, utilizing both control point tests and dosimetric measurements are presented.Methods and Materials
A generalizable, phantom measurement approach is used to characterize the accuracy of the measurement system. Correction for angular response of the measurement system and inclusion of couch structures are used to characterize the full range gantry angles desirable for clinical plans. A dose based daily QA measurement approach is defined.Results
Agreement in the static vs. VMAT picket fence control point test was better than 0.5 mm. Control point tests varying gantry rotation speed, leaf speed and dose rate, demonstrated agreement with predicted values better than 1%. Angular dependence of the MatriXX array, varied over a range of 0.94–1.06, with respect to the calibration condition. Phantom measurements demonstrated central axis dose accuracy for un-modulated four field box plans was ≥2.5% vs. 1% with and without angular correction respectively with better results for VMAT (0.4%) vs. IMRT (1.6%) plans. Daily QA results demonstrated average agreement all three chambers within 0.4% over 9 month period with no false positives at a 3% threshold.Discussion
The methodology described is simple in design and characterizes both the inherit limitations of the measurement system as well at the dose based measurements that may be directly related to patient plan QA. 相似文献11.
Dhanabalan Rajasekaran Prakash Jeevanandam Prabakar Sukumar Arulpandiyan Ranganathan Samdevakumar Johnjothi Vivekanandan Nagarajan 《Reports of Practical Oncology and Radiotherapy》2015,20(1):57-65
Aim
To evaluate the new Octavius 4D system for patient specific quality assurance and to study the correlation between plan complexity and gamma index analysis in patient specific quality assurance of VMAT using the Octavius 4D system.Background
McNiven (2010) proposed a study to evaluate the utility of a complexity metric, the Modulation Complexity Score, to evaluate the relationship of the metric with deliverability in IMRT.Materials and methods
Evaluation of the Octavius 4D system was carried out by gamma evaluation of user defined MLC created patterns and AAPM TG 119 benchmark plans. The relationship between plan complexity expressed as Modulation Complexity Score (MCS) and the gamma index analysis was established by a planar and volumetric gamma analysis of 106 clinically approved VMAT patient plans of different sites.Results
Average volumetric 3D global gamma evaluation (3 mm/3%) results for the evaluation plans was 97.41% for 6 MV X-rays and 98.30% for 15 MV X-rays. Average MCS values for the head and neck, pelvic and thoracic plans were 0.2224, 0.3615 and 0.1874. Average volumetric 3D global gamma analysis (3 mm/3%) results for the head and neck, pelvic and thoracic VMAT plans were 95.45%, 97.51% and 96.98%, respectively. Out of 90 correlation analyses between the MCS and gamma passing rate, only 3 had the r value greater than 0.5.Conclusions
The Octavius 4D system is a suitable device for patient specific pretreatment QA. Global and local gamma analysis results showed a weak correlation with the MCS. 相似文献12.
Laurence M. Renard Valery Bocquet Gwenaelle Vidal-Trecan Marie-Lise Lair Claudine Blum-Boisgard 《PloS one》2013,8(11)
Introduction
Type 2 diabetes is associated with severe micro- and macro-vascular complications. Physicians’ and patients’ adherence to follow-up guidelines permits postponing or reducing these complications. The objectives were to assess the level of adherence to fundamental follow-up guidelines and determine patients’ characteristics associated with this level of adherence in the context of Luxembourg, where no guidelines were implemented.Study population
The exhaustive residing population treated for type 2 diabetes in Luxembourg during the 2000-2006 period (N = 21,068).Methods
Seven fundamental criteria were extracted from international guidelines (consultation with the treating physician, HbA1c tests, electrocardiogram, retinal, dental, lipid and renal check-ups). The factors associated with the level of adherence to those criteria were identified using a partial proportional odds model.Results
In 2006, despite 90% of the patients consulted at least 4 times their treating physician, only 0.6% completed all criteria; 55.0% had no HbA1c test (−8.6 points since 2000) and 31.1% had a renal check-up (+21.6 points). The sex (ORmale: 0.87 [95%CI, 0.83−0.92]), the nationality (ORNonEU: 0.64 [0.52−0.78]), the type of antidiabetic treatment (ORoral: 1.48 [1.35−1.63], ORmixed: 1.35 [1.20−1.52]) and the type of treating physician (ORG-ID: 0.47 [0.42−0.53]) were the main factors associated with the level of adherence in 2006 (3 or more criteria).Conclusion
A large percentage of patients were not provided with a systematic annual follow-up between 2000 and 2006. This study highlighted the necessity to promote guidelines in Luxembourg, education for physicians and to launch a national discussion on a disease management program for diabetic patients. 相似文献13.
Background
Inhaled iloprost potentially improves hemodynamics and gas exchange in patients with chronic obstructive pulmonary disease (COPD) and secondary pulmonary hypertension (PH).Objectives
To evaluate acute effects of aerosolized iloprost in patients with COPD-associated PH.Methods
A randomized, double blind, crossover study was conducted in 16 COPD patients with invasively confirmed PH in a single tertiary care center. Each patient received a single dose of 10 µg iloprost (low dose), 20 µg iloprost (high dose) and placebo during distinct study-visits. The primary end-point of the study was exercise capacity as assessed by the six minute walking distance.Results
Both iloprost doses failed to improve six-minute walking distance (p = 0.36). Low dose iloprost (estimated difference of the means −1.0%, p = 0.035) as well as high dose iloprost (−2.2%, p<0.001) significantly impaired oxygenation at rest. Peak oxygen consumption and carbon dioxide production differed significantly over the three study days (p = 0.002 and p = 0.003, accordingly). As compared to placebo, low dose iloprost was associated with reduced peak oxygen consumption (−76 ml/min, p = 0.002), elevated partial pressure of carbon dioxide (0.27 kPa, p = 0.040) and impaired ventilation during exercise (−3.0l/min, p<0.001).Conclusions
Improvement of the exercise capacity after iloprost inhalation in patients with COPD-associated mild to moderate PH is very unlikely.Trial Registration
Controlled-Trials.com ISRCTN61661881 相似文献14.
Katia Alikaniotis Oscar Borla Valeria Monti Gianna Vivaldo Alba Zanini Gianrossano Giannini 《Reports of Practical Oncology and Radiotherapy》2016,21(2):117-122
Aim
To employ the thermal neutron background that affects the patient during a traditional high-energy radiotherapy treatment for BNCT (Boron Neutron Capture Therapy) in order to enhance radiotherapy effectiveness.Background
Conventional high-energy (15–25 MV) linear accelerators (LINACs) for radiotherapy produce fast secondary neutrons in the gantry with a mean energy of about 1 MeV due to (γ, n) reaction. This neutron flux, isotropically distributed, is considered as an unavoidable undesired dose during the treatment. Considering the moderating effect of human body, a thermal neutron fluence is localized in the tumour area: this neutron background could be employed for BNCT by previously administering 10B-Phenyl-Alanine (10BPA) to the patient.Materials and methods
Monte Carlo simulations (MCNP4B-GN code) were performed to estimate the total amount of neutrons outside and inside human body during a traditional X-ray radiotherapy treatment.Moreover, a simplified tissue equivalent anthropomorphic phantom was used together with bubble detectors for thermal and fast neutron to evaluate the moderation effect of human body.Results
Simulation and experimental results confirm the thermal neutron background during radiotherapy of 1.55E07 cm−2 Gy−1.The BNCT equivalent dose delivered at 4 cm depth in phantom is 1.5 mGy-eq/Gy, that is about 3 Gy-eq (4% of X-rays dose) for a 70 Gy IMRT treatment.Conclusions
The thermal neutron component during a traditional high-energy radiotherapy treatment could produce a localized BNCT effect, with a localized therapeutic dose enhancement, corresponding to 4% or more of photon dose, following tumour characteristics. This BNCT additional dose could thus improve radiotherapy, acting as a localized radio-sensitizer. 相似文献15.
Line Sletner Britt Nakstad Chittaranjan S. Yajnik Kjersti M?rkrid Siri Vangen Mari H. V?rdal Ingar M. Holme K?re I. Birkeland Anne Karen Jenum 《PloS one》2013,8(8)
Background
Neonates from low and middle income countries (LAMIC) tend to have lower birth weight compared with Western European (WE) neonates. Parental height, BMI and maternal parity, age and educational level often differ according to ethnic background, and are associated with offspring birth weight. Less is known about how these factors affect ethnic differences in neonatal body composition.Objectives
To explore differences in neonatal body composition in a multi-ethnic population, and the impact of key parental factors on these differences.Methods
A population-based cohort study of pregnant mothers, fathers and their offspring, living in Oslo, Norway. Gender- and gestational-specific z-scores were calculated for several anthropometric measurements, with the neonates of WE ethnic origin as reference. Mean z-scores for neonates with LAMIC origin, and their parents, are presented as outcome variables.Results
537 singleton, term neonates and their parents were included. All anthropometric measurements were smaller in neonates with LAMIC origin. Abdominal circumference and ponderal index differed the most from WE (mean z-score: −0.57 (95% CI:−0.69 to −0.44) and −0.54 (−0.66 to −0.44), and remained so after adjusting for parental size. Head circumference and skin folds differed less, and length the least (−0.21 (−0.35 to −0.07)). These measures became comparable to WEs when adjusted for parental factors.Conclusions
LAMIC origin neonates were relatively “thin-fat”, as indicated by reduced AC and ponderal index and relatively preserved length and skin folds, compared with neonates with WE origin. This phenotype may predispose to type 2 diabetes. 相似文献16.
Anna Bandurska-Luque Tomasz Piotrowski Agnieszka Skroba?a Adam Ryczkowski Krystyna Adamska Joanna Ka?mierska 《Reports of Practical Oncology and Radiotherapy》2015,20(2):145-152
Aim
This prospective study aims to assess feasibility of helical tomotherapy (HT) for craniospinal irradiation (CSI) and perform dosimetric comparison of treatment plans for both HT and 3D conformal radiotherapy (3DCRT).Background
CSI is a challenging procedure. Large PTV size requires field matching due to technical limitations of standard linear accelerators, which cannot irradiate such volumes as a single field. HT could help to avoid these limitations as irradiation of long fields is possible without field matching.Materials and methods
Three adults were enrolled from 2009 to 2010. All patients received radiochemotherapy. Treatment plans in prone position for 3DCRT and in supine position for HT were generated. The superior plan was used for patients’ irradiation. Plans were compared with the application of DVH, Dx parameters – where x represents a percentage of the structure volume receiving a normalized dose and homogeneity index (HI).Results
All patients received HT irradiation. The treatment was well tolerated. The HT plans resulted in a better dose coverage and uniformity in the PTV: HI were 5.4, 7.8, 6.8 for HT vs. 10.3, 6.6, 10.4 for 3DCRT. For most organs at risk (OARs), the D(V80) was higher for HT than for 3DCRT, whereas D(V5) was lower for HT.Conclusions
HT is feasible for CSI, and in comparison with 3DCRT it improves PTV coverage. HT reduces high dose volumes of OARs, but larger volumes of normal tissue receive low radiation dose. HT requires further study to establish correlations between dosimetrical findings and clinical outcomes, especially with regard to late sequelae of treatment. 相似文献17.
Thibaud P. Coroller Raymond H. Mak John H. Lewis Elizabeth H. Baldini Aileen B. Chen Yolonda L. Colson Fred L. Hacker Gretchen Hermann David Kozono Edward Mannarino Christina Molodowitch Jon O. Wee David J. Sher Joseph H. Killoran 《PloS one》2014,9(4)
Purpose
To examine the frequency and potential of dose-volume predictors for chest wall (CW) toxicity (pain and/or rib fracture) for patients receiving lung stereotactic body radiotherapy (SBRT) using treatment planning methods to minimize CW dose and a risk-adapted fractionation scheme.Methods
We reviewed data from 72 treatment plans, from 69 lung SBRT patients with at least one year of follow-up or CW toxicity, who were treated at our center between 2010 and 2013. Treatment plans were optimized to reduce CW dose and patients received a risk-adapted fractionation of 18 Gy×3 fractions (54 Gy total) if the CW V30 was less than 30 mL or 10–12 Gy×5 fractions (50–60 Gy total) otherwise. The association between CW toxicity and patient characteristics, treatment parameters and dose metrics, including biologically equivalent dose, were analyzed using logistic regression.Results
With a median follow-up of 20 months, 6 (8.3%) patients developed CW pain including three (4.2%) grade 1, two (2.8%) grade 2 and one (1.4%) grade 3. Five (6.9%) patients developed rib fractures, one of which was symptomatic. No significant associations between CW toxicity and patient and dosimetric variables were identified on univariate nor multivariate analysis.Conclusions
Optimization of treatment plans to reduce CW dose and a risk-adapted fractionation strategy of three or five fractions based on the CW V30 resulted in a low incidence of CW toxicity. Under these conditions, none of the patient characteristics or dose metrics we examined appeared to be predictive of CW pain. 相似文献18.
Daniela Muenzel Thomas Koehler Kevin Brown Stanislav ?abi? Alexander A. Fingerle Simone Waldt Edgar Bendik Tina Zahel Armin Schneider Martin Dobritz Ernst J. Rummeny Peter B. No?l 《PloS one》2014,9(9)
Purpose
Evaluation of a new software tool for generation of simulated low-dose computed tomography (CT) images from an original higher dose scan.Materials and Methods
Original CT scan data (100 mAs, 80 mAs, 60 mAs, 40 mAs, 20 mAs, 10 mAs; 100 kV) of a swine were acquired (approved by the regional governmental commission for animal protection). Simulations of CT acquisition with a lower dose (simulated 10–80 mAs) were calculated using a low-dose simulation algorithm. The simulations were compared to the originals of the same dose level with regard to density values and image noise. Four radiologists assessed the realistic visual appearance of the simulated images.Results
Image characteristics of simulated low dose scans were similar to the originals. Mean overall discrepancy of image noise and CT values was −1.2% (range −9% to 3.2%) and −0.2% (range −8.2% to 3.2%), respectively, p>0.05. Confidence intervals of discrepancies ranged between 0.9–10.2 HU (noise) and 1.9–13.4 HU (CT values), without significant differences (p>0.05). Subjective observer evaluation of image appearance showed no visually detectable difference.Conclusion
Simulated low dose images showed excellent agreement with the originals concerning image noise, CT density values, and subjective assessment of the visual appearance of the simulated images. An authentic low-dose simulation opens up opportunity with regard to staff education, protocol optimization and introduction of new techniques. 相似文献19.
Galit Kleiner-Fisman Edwin Khoo Nikohl Moncrieffe Triina Forbell Pearl Gryfe David Fisman 《PloS one》2014,9(12)
Objective
Evaluate safety and efficacy of Incobotulinumtoxin A in elderly patients with dementia and paratonia.Setting
University-affiliated hospital, spasticity management Clinic.Participants
Ten subjects were enrolled. Inclusion criteria: 1) severe cognitive impairment 2) diagnosis of Alzheimer’s disease, vascular dementia, or frontotemporal dementia, and 3) score >3 on the paratonic assessment instrument, with posture in an arm(s) interfering with provision of care. Exclusion criteria: 1) alternate etiologies for increased tone and 2) injection with botulinum toxin within the 6 months preceding the study.Design
Single center, randomized, double blind, placebo-controlled, crossover trial with two treatment cycles of 16 weeks. Assessments occurred at 2, 6, 12 and16 weeks following injections. Subjects received up to 300 U of Incobotulinumtoxin A in arm(s).Primary and Secondary Outcome Measures
Primary outcome measure was the modified caregiver burden scale (mCBS); exploratory secondary outcome measures were also performed. Analysis of variance and mixed modeling techniques were used to evaluate treatment effects.Results
Incobotulinumtoxin A treatment produced significant improvement in mCBS total score −1.11 (–2.04 to −0.18) (Treatment effect and 95% CI), dressing sub-score −0.36 (–0.59 to 0.12), and cleaning under the left and right armpits sub-score −0.5 (–0.96 to −0.04), −0.41 (–0.79 to −0.04) respectively. PROM in the left and right elbow increased by 27.67 degrees (13.32–42.02) and 22.07 degrees (9.76–34.39) respectively. PROM in the left and right shoulder increased by 11.92 degrees (5.46–18.38) and 8.58 degrees (3.73–13.43) respectively. No significant treatment effect was found for GAS, VAS and PAINAD scales or change in time to perform care. No adverse drug reactions occurred.Conclusions
Administration of Incobotulinumtoxin A in elderly people with advanced dementia and paratonia may be an efficacious and safe treatment to increase range of motion and reduce functional burden. Further studies are needed to confirm results.Trial Registration
ClinicalTrials.Gov NCT02212119相似文献20.
Guang-cong Liu Guo-yuan Sui Guang-ying Liu Yang Zheng Yan Deng Yan-yan Gao Lie Wang 《PloS one》2013,8(11)