Quantification and construction of the effective point calculation model of ionization chamber in Monacao treatment planning system / 中华放射肿瘤学杂志

Objective Because of statistical noise in Monte Carlo dose calculations,the effective point doses may not be accurately calculated.A user-defined sphere volume was adopted to substitute the effective point to take sphere sampling around the effective point,which minimize the random errors and improve the accuracy of statistical dose.Methods Direct dose measurements were performed at 0°and 90° using a 0.125 cm3 Semiflex ionization chamber (IC) 31010 isocentrically placed in the center of a homogeneous Cylindric sliced RW3 phantom (PTW,Germany).In the scanned CT phantom series,the sensitive volume length of the IC (6.5 mm) was delineated and the isocenter was defined as the simulated effective point.All beams were simulated in the treatment planning system (TPS) in accordance to the measured model.The grid spacing was calculated by 2 mm voxels and the relative standard deviation should be ≤ 0.5％.The statistical and measured doses were statistically compared among three IC models with different electron densities (ED;esophageal lumen ED =0.210 g/cm3 for model A,air ED =0.001 g/cm3 for model B and the default CT scanned ED for model C) at different sampling sphere radius (2.5,2.0,1.5 and 1.0 mm) to evaluate the effect of Monte Carlo.calculation uncertainty upon the dose accuracy.Results In the Monaco TPS,the statistical value was in the highest accordance with the measured value with an absolute average deviation of 0.49％ when the IC was set as esophageal lumen ED =0.210 g/cm3 and the sampling sphere radius was 1.5 mm.When the IC was set as air ED=0.001 g/cm3 and default CT scanned ED,and,the recommended statistical sampling sphere radius was 2.5 mm,the absolute average deviations were 0.61％ and 0.70％.Conclusion In the Monaco TPS,the calculation model with an ED of 0.210 g/cm3 and a sampling radius of 1.5 mm is recommended for the ionization chamber 31010 to substitute the effective point dose measurement to decrease the random stochastic errors of Monte Carlo.

Application of disease screening with magnetically controlled capsule endoscopy / 中国内镜杂志

Objective To study the clinical value of magnetically controlled capsule endoscopy in diseases screening. Method We retrospectively analyzed 61 cases which were evaluated by magnetically controlled capsule endoscopy from March 2015 to December 2016. The items include operating time, the divergence rate score and cleanliness score of stomach. The consistency was compared between magnetically controlled capsule endoscopy and gastric duodenal endoscopy. Results 61 upper gastrointestinal tract studies were included. The mean age was (49.4 ± 11.6) years. No capsule retention, perforation or bleeding occurred. There was 98.4% patients, which cleanliness of stomach was good. There was 68.9% patients, which filling degree of stomach was good. The concordance rate of the two tests of gastrduodenoscopy and magnetically controlled capsule endoscopy was 89.9% (80/89). The concordance rate of the two tests was 78.9% (15/19) in esophageal and cardia, 92.9% (52/56) in stomach, 92.9% (13/14) in duodenum. Conclusion Our experience shows that magnetically controlled capsule endoscopy is a safe and useful tool for the diagnosis of upper gastrointestinal tract disease. The detection rate is similar to gastrduodenoscopy.

The clinical observation of advanced primary liver cancer under the chemotherapy of hyperthermia combined with EOF approach / 中国基层医药

Objective To discuss the clinical efficacy of advanced primary liver cancer under the chemother-apy of hyperthermia combined with EOF approach.Methods 75 patient samples who had advanced primary liver cancer in total were chosen and were divided into the two groups randomly.The control group containing 37 patient samples had advanced primary liver cancer which would be applied with EOF approach.The treatment group contai-ning 38 samples had advanced primary liver cancer.The treatment strategy was to apply EOF approach combined with high -frequency hyperthermia in vitro.Results The total rate of efficiency on the treatment group and control group was 73.68% vs 48.6%.The DCR rate was 92.1% versus 56.8%,1 year survival rate was 57.8% versus 45.9%and 2 years survival rate was 10.5% versus 5.4% which showed that the results of the treatment group was obviously better than that of the control group.Conclusion The method that combining the chemotherapy of hyperthermia with EOF to treat advanced primary liver cancer can obviously improve clinical efficacy and survival period.What′s better is that this approach will not increase the toxicity of chemotherapy.

Value of echocardiography in the diagnosis of aortico-left ventricular tunnel / 中华超声影像学杂志

Objective To evaluate the clinical value of echocardiography in the diagnosis of aorticoleft ventricular tunnel.Methods The echocardiographic and clinical characteristics were retrospectively analyzed in 6 patients with aortico-left ventricular tunnel we reported and 147 cases that documents reported.Results Six patients were confirmed by operation.The main echocardiographic characteristics of aortico-left ventricular tunnel were as follows:An abnormal communication began in the ascending aorta above the level of the coronary arteries,bypassed the aortic valve,and terminated in the left ventricle.The color Doppler flow imaging demonstrated to-and-fro flow,with or without aortic valve involvement.According Hovaguimian and his colleagues,2 cases were type Ⅰ,2 cases were type Ⅲ,1 case was type Ⅳ,1 case was type Ⅱ (showed as recanalization).Base on all of the 153 patients that we and documents reported,the accuracy rate of ultrasound diagnosis was 79.6％,the misdiagnosis rate was 17.1％,and missed diagnosis rate was 3.3 ％.Conclusions Echocardiography is the non-invasive and sensitive tool in the diagnosis of the type of aortico-left ventricular tunnel and structure of cardiac involvement,and is the preferred method for preoperative.