Explanation of health requirements and surveillance specifications for radiation worker / 中华放射医学与防护杂志

Chinese National Standards GBZ 98-2020 Health Requirements and Surveillance Specifications for Radiation Worker was published and will replace the current standards GBZ 98-2017 Health Requirements for Radiation Workers and GBZ 235-2011 Specifications for Occupational Health Surveillance for Radiation Workers from May 1 in 2021. The significance of this new National Standards, the background, basic principles, basis of revision of important indicators and the matters needing attention in the application of the standard are described in detail, especially for the medical institutions carrying out occupational health examination requirements, the determination of occupational health examination items, examination method and examination reports, so as to avoid the possible misunderstandings and doubts in using the standards.

Measurement of gross β activity in urine of normal adults / 中华放射医学与防护杂志

Objective To measure the total β radioactive background level in the urine of normal adults,and to establish the method which can be universally used and satisfy the needs of rapid screening of samples in large batch.Methods A total of 83 urine samples from healthy adults were prepared by evaporation.And the gross β activity in urine was detected by using low background measuring instrument.Results The optimal experimental conditions were in place.The sampled volume was 200 ml,and the samples were turned to nitric acid salinization,ashed at 300℃ for 2 h,and the measured time was 1000 min.To get a more stable result,the urine residues were put aside for 24 h before measurement.The radioactivity in urine of healthy adults was between 9.40-55.92 Bq/L,and showed no correlation with age and sex.Conclusions When the radioactivity in urine is detected under the conditions mentioned above,the sample preparation process is simple and quickly,which can satisfy the needs of large batch sample screening.

Radiosensitivity enhancement of recombimant adenoviral-mediated retinoblastoma 94 gene in human esophageal carcinoma cells / 中华放射医学与防护杂志

Objective To study the radiosensitivity enhancement effects of recombinant adenovirus mediated retinoblastoma 94 gene on the growth of esophageal carcinoma cells EC109.Methods EC109cells was transfected with recombinant Rb94 gene adenovirus and irradiated by 137Cs γ-rays.The cohorts were divided into groups as blank control,Ad-LacZ,Ad-Rb94,radiation and Ad-Rb94 combined with radiation.Cell inhibition ratio,cell cycle and expression of retinoblastoma protein of EC109 cells were analyzed.Results The growth of EC109 cells transfected with Ad-Rb94,radiation and Ad-Rb94 combined with radiation group was all inhibited.The group of Ad-Rb94 combined with radiation resulted in greater inhibition of cells growth compared with Ad-Rb94 group and radiation group ( F =23.31,P ＜0.05 ).Cells of G2 phases of EC109 cancinoma cells for Ad-Rb94 combined with radiation group were the highest,which was 50％.The combination of Ad-Rb94 and radiation group resulted in the greatest expression of retinoblastoma protein,which reached 71％,significantly higher than Ad-Rb94 infection and radiation groups ( x2 =8.31,6.73,P ＜ 0.05 ).Conclusions Retinoblastoma 94 gene combined with ionizing radiation can enhance the radiation sensitivity of EC109 cells.

Radiation dose to patients in cardiovascular disease interventional procedures / 中华放射医学与防护杂志

Objective To collect and analyze the radiation dose to patients in cardiovascular interventional procedures and the radiation dose-related indicators,in order to provide a basis for improving radiation protection of patients.MethodsThe clinical data of 26 cases of complete cardiovascular interventional procedures was collected in the municipal Grade A Class Three hospitals,including coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA),and the patient-received radiation doses and other related factors was studied.TLD personal dosimeter radiation field matrix method was used to measure fluorescence time,the entrance skin dose (ESD),the peak skin dose (PSD),dosearea product (DAP) and other indicators.TLD was used to measure the organ dose of the phantom under the cardiovascular interventional procedure condition.ResultsThe fluoroscopy time was (17.7 ±15.6) min during the range of 0.80-42.4 min.The average entrance skin dose (ESD) was (159 ± 138)mGy during the range of 4.40-459 mGy.The peak skin dose (PSD) was (769 ± 705) mGy during the range of 22.6 - 2.43 × 103mGy.The fluorescence time,entrance skin dose (ESD) ,peak skin dose (PSD) of the group CA + PTCA are greater than the group CA and the difference has statistical significan.The peak skin dose and the fluoroscopy time have good linear correlation (r = 0.84,P ＜ 0.01 ).Conclusion The peak skin dose the patient received in cardiovascular interventional radiological operation can be estimated through the fluoroscopy time.