Approximately 1000 monthly CT exams (adult and pediatric) were reviewed. The project was well accepted by the operational team and referred by the hospital’s quality department for certification assessment.
DIR reports were important for warning signs for outliers. However, it must be considered that IR parameter applies an American reference level, and there are differences in the biotypes of the Brazilian population and the technological equipment in Brazil.
The incidence of pediatric CT exams in each semester:
- head (N=322; 62%);
- abdomen (N=153; 29.8%);
- chest (N=20; 3.9%);
- spine (N=17; 3.3%).
The incidence of the adults CT exams and assessment dose of 25th, median and 75th without contrast was:
- head (35.5%; CDTI vol: 26/26/26; DLP: 574/590/697);
- abdomen (26.7%; CDTI vol: 11/14/17; DLP: 548/703/933);
- face (22%; CDTI vol: 19/19/19; DLP: 340/355/375);
- chest (11.6%; CDTI vol: 6/7/9; DLP: 220;273,357);
- spine (4.2%; CDTI vol: 14/19/25; DLP: 343/465/635.
After the recommendation it was observed a reduction of the median CTDI vol per scan for pediatric age group CT realized in the period from January 2019 to June 2020:
- Abdominal/pelvis CT Scan
- 300% of reduction for 0 to 2 years old;
- 67% of reduction for 11 to 14 years old;
- 33% of reduction for 3 to 6 years old.
b. Chest CT Scan
- 100% of reduction for 0 to 6 years old;
- 50% of reduction for 11 to 14 years old.
After the implementation of dose monitoring with the analysis of the periodic dose reports, the hospital applied some recommendations and there was a reduction in the CTDI vol, SSDE and DLP per scan parameters prevalent in the 0 to 6 year age groups, for the abdomen-pelvis and chest CT exams, as well as 11-14 years old. But more optimization must be done.
Adults CT showed lower dose on head and chest according to DIR parameters; and image quality was verified. But more optimization must be done to abdominal and spine adult CT.
Table 01 and 02 show an example of the CT pediatric dose according to DIR, SSDE, CTDI vol, DLP per scan from January 2019 to June 2020.
The Graphic 1 and 2 represents an example of Facility Perfomance on 10 High Volume DIR Exams (Adult/Pediatric).
Optimizating action:
- Reduction in the length and number of CT phases, dose adjustment according to the weight of the patient, Z-Axis Dose Modulation was suggested according to the data analysis;
- Verify if there was recent previous exams and alert the radiologist;
- Guidance on justification with physicians;
- Motivation for using of non-ionizing radiation tests (magnetic resonance and ultrasound);
- Re-evaluation of the protocols according to international references;
- Permanent education will be applied in the future by the department coordinator.
Team perception
The monitoring dose software was well accepted by the group of employees and contributed to the technicians’ awareness about the appropriate radiation dose.
An anonymous self-administered structured questionnaire, three questions and a Likert scale (totally agree; partially agree; totally disagree and partially agree) was applied in 2020 to all the technicians in tomography department (N=15) about their perception of the daily operational of the monitoring system. 13 out of 15 technicians responded the questionnaire. The Graphic 3 represents the technicians's answers of the questionnaires about their perceptions of the dose monitoring system. Usually the radiologist do not check the dose report daily and training course will be planned.
Future education actions
- The justification program will be applied by the hospital leaders.
- Couching feed back will be done to the requester (graphic 4 shows the incidence of types of exams requested).
- Training courses will be applied to radiologist, technicians and requesters.
- Technicians and radiologists suggested to apply automatic monitoring dose to radiographic exams.
- The hospital will apply an intelligence algorithm to X-Ray and mammography service on 2021.