The measurement of absolute dose in radiation therapy / 中国医疗器械杂志

This article presents and discusses the measurement of absolute dose in radiation therapy, aiming to achieve the requires of quality assurance in radiotherapy by WHO and enhance the tumor control probability.

Some special problems about the usement of wedge field in radiation therapy / 中国医疗器械杂志

This article presents and discusses some special problems about the use of wedge field in radiation therapy according to the practice of the author. Thus we attain the rules of quality assurance in radiotherapy by WHO.

The effect of ventilator circuit change frequency on ventilator-associated pneumonia incidence / 中国综合临床

Objective To explore the effect of ventilator circuit change frequency on the incidence of ventilator-associated pneumonia (VAP). Methods Patients receiving mechanical ventilation in the ICU,Department of Emergency, Respiratory Department and Department of Neurosurgery from March 2008 to September 2010 were randomized into two groups. For these two groups ,the ventilator circuit was changed once or twice a week. The recorded parameters included the clinical symptoms and signs of the ventilated patients. Samples at different parts of the circuit were collected for microbiological detection. The data were analyzed statistically. Results The incidence of VAP was 28. 30% ( 13/53 ) in twice-a-week group and 35.84%( 19/53 ) in once-a-week group. There was no significant difference between the two groups. The rates for positive microbiological detection in the circuit were 48. 16% and 44. 49% for once-a-week and twice-a-week group,respectively. No significant difference was observed ( P ＞ 0.05 ). Moreover, there was no significant difference in terms of the microbiology positivity between different parts of the circuit(P ＞ 0. 05 ). Gram-negative bacteria were the main pathogen of VAP with Acinetobacter baumannii ranking at the top. Conclusion Frequency of Ventilator circuit change does not influence the incidence of VAP. We suggest that the frequency for ventilator circuit change should be once a week. At the same time, the nurse staff should be trained for specific technology and the incidence of hospital infection should be controlled at multiple rings of the chain.

Some special problems and countermeasure about dose calibration of high-energy electron for linear accelerator / 中国医疗器械杂志

This article presents and discusses some special problems about the dose calibration of high-energy elections for Linear Accelerator according to the practice of the authors. Thus the paper explain the issues of this work, and clarify the wrong understanding of real work for the aim of attaining the rules of quality assurance in radiotherapy by WHO.

Dose calibration of high-energy electron for linear accelerator / 医疗卫生装备

Objective To calibrate the dose of 12MeV high-energy electron for Siemens MD7745 medical linear accelerator.Methods The international protocols,contents and technical standards were expatiated.Some existing problems in dose calibration of high-energy electron were analyzed.Results The working precision met the requirement of quality assurance in radiotherapy by WHO.Conclusion In order to improve the therapeutic effect,the dose must be calibrated,and the error in dose calibration of high-energy electron should be reduced to the lowest.