Investigation and analysis on level of medical exposure in radiodiagnosis and radiotherapy in Jiangsu Province in 2016

Yuanyuan Zhou, Ningle Yu, Jiayi Ma, Xiaoyong Yang, Wei Chen, Xiaodong Shi, Xiang Du, Chunyong Yang, Furu Wang, Jin Wang


Background: The aim of the present study is to investigate the frequency and the dose level of the medical exposure and estimate the distribution of the medical radiation in Jiangsu 2016, which can establish foundation to improve the protection of the medical irradiation.
Methods: All the medical institutions were covered in the fundamental information survey and 31 medical institutions were sampled to investigate the medical radiation frequency and the dose level. All the medical radiation information in 2016 were gathered in the sample hospital and a liner model were established to evaluate the medical radiation frequency in the whole province in 2016. The nuclear medicine diagnosis and therapy frequency were calculated by the inpatient number in sample hospitals and the whole province respectively. The exposure parameter, the dose information displayed in the equipment and the patient information of the digital radiography (DR) and CT in the sample hospitals were investigated and some dose level parameters were measured by a radio-dosimeter.
Results: By the end of the 2016, there were 9,248 medical radiation equipment in Jiangsu. The number of CT, linear accelerator and nuclear medicine (PET, SPECT) increased of 3.6, 5.2 and 5.0 times respectively, compared with the investigation results in 1999. The results showed that the frequency of radio-diagnostic, radio-therapy, nuclear medicine diagnostic, and nuclear medicine therapy was 710.85 (include CT 240.21), 2.80, 15.44, and 0.37 procedures per 1,000 persons. The results of the dose level indicated that the 75th percentile of the PA-chest, lumbar spine and the hip joint view were higher than the diagnostic reference level (DRL) in GB18871-2002. The 75th percentile value of the CT head and CT chest scan is 691 and 483 mGy·cm respectively, which is higher than the DRL in GBZ165. The 75th percentile values of the CTDI (computed tomography dose index) vol in all age groups of pediatric CT scans were higher than the DRL in which the 75th percentile value of the CTDI vol is 1.8 times higher than the DRL.
Conclusions: It is important to capture the frequency and the dose level of the medical radiation in Jiangsu Province and find out the vulnerable spot of the medical radiation protection. The results of the present investigation provided us the basic information to improve the distribution of the resources in radiation protection and enhance the protection of the patients.