PEDIATRIC REGIONAL DRL ASSESSMENT IN COMMON CT EXAMINATIONS FOR MEDICAL EXPOSURE OPTIMIZATION IN TEHRAN, IRAN

Estimation of diagnostic reference levels for pediatric head computed tomography in Yaoundé

The diagnostic reference levels (DRLs) are determined from dosimetry studies to compare and manage patient doses in medical imaging procedures. The aim of this work was to establish the first DRLs for pediatric patients during the most common computed tomography (CT) procedures in Yaoundé, Cameroon during routine head CT examinations to know how to improve our clinical practice tomorrow. The sample was classified per age group: ≤ 1-, 1-5-, 5-10- and 10-15-y-old. The retrospective study was used. The proposed DRLs were defined as 75th percentile of the median values of the distributions. In terms of Volume CT Dose Index (CTDIvol) and dose length product (DLP), the DRLs obtained for the ages groups were: 28.6 mGy and 545.8 mGy.cm, 32.6 mGy and 735 mGy.cm, 37.1 mGy and 761.6 mGy.cm and 44.2 mGy and 1081.2 mGy.cm, respectively. DRLs in Yaoundé for DLP were higher than those of comparison literatures. The Yaoundé CTDIvol was higher than the comparison literatures except for the IAEA (2015) values for the three older age groups. The DRLs reported in Yaoundé were compared to Morocco 2020, Switzerland 2018, IAEA 2015 and Iran 2020 values. The estimation of this first DRL for pediatric head CT scan in Yaoundé must be a starting point to spread this investigation towards other examinations and imaging modalities across the country. Therefore, optimization of the CT scan procedures and orderly updates of local DRLs are necessary to improve radioprotection.

ESTABLISHMENT OF LOCAL DIAGNOSTIC REFERENCE LEVEL FOR ROUTINE PAEDIATRIC COMPUTED TOMOGRAPHY EXAMINATIONS IN BAFOUSSAM WEST CAMEROON

The main purpose of this study was to determine local diagnostic reference level (LDRL) for routine computed tomography (CT) examination in Bafoussam, western Cameroon. The exposure parameters and dose quantities were collected manually. This retrospective, evaluative and comparative study was conducted to determine LDRLs for routine head CT examination in Bafoussam, to optimize these procedures in the region. The 75th percentile values of the calculated volume CT dose index (CTDIvol) and dose length product (DLP) were proposed as LDRL. The sample was classified in four age groups: < 1, 1-5, 5-10 and 10-15 y. The LDRLs obtained for the four age groups were: 24 mGy and 381.32 mGy.cm, 42.5 mGy and 875.55 mGy.cm, 45.85 mGy and 939.62 mGy.cm, 57.12 mGy and 1222.3 mGy.cm, respectively. The 75th percentile CTDIvol and DLP dose values for this study are higher than international values. We propose a coordinating discussions and collaboration about patient's and specific equipment's change information's, between radiologists, medical imaging technicians and medical physicist, which can reduce absorbed doses and improved medical practice in hospitals.

Pediatric effective dose assessment for routine computed tomography examinations in Tehran, Iran

Background:

The purpose of this study is to evaluate the effective dose (ED) for computed tomography (CT) examination in different age groups and medical exposure in pediatric imaging centers in Tehran, Iran.

Methods:

Imaging data were collected from 532 pediatric patients from four age groups subjected to three prevalent procedures. National Cancer Institute CT (NCICT) software was used to calculate the ED value.

Results:

The mean ED values were 1.60, 4.16, and 10.56 mSv for patients' procedures of head, chest, and abdomen–pelvis, respectively. This study showed a significant difference of ED value among five pediatric medical imaging centers (P < 0.05). In head, chest, and abdomen–pelvis exams, a reduction in ED was evident with decreasing patients' age.

Conclusion:

As there were significant differences among ED values in five pediatric medical imaging centers, optimizing this value is necessary to decrease this variation. For head CT in infants and also abdomen–pelvis, further reduction in radiation exposure is required.

ESTIMATION OF DIAGNOSTIC REFERENCE LEVELS AND ACHIEVABLE DOSES FOR PEDIATRIC PATIENTS IN COMMON COMPUTED TOMOGRAPHY EXAMINATIONS: A MULTI-CENTER STUDY

This study was conducted to determine first local diagnostic reference levels (DRLs) and achievable doses (ADs) for pediatric patients during the most common computed tomography (CT) procedures in Yazd province. The DRL was obtained based on volume CT dose index (CTDIvol) and dose length product (DLP) for four various age groups of children. Data were collected from the most commonly performed pediatric CT scans, including abdomen-pelvis, chest, brain and sinus examinations, at six high-loaded institutes. The patients' data (766 no.) in terms of CTDIvol and DLP were obtained from four age groups: ≤1-, 1-5-, 5-10- and 10-15-y-old. The 75th percentiles of CTDIvol and DLP were considered as DRL values and the 50th percentiles were described as ADs for those parameters. Consequently, the acquired DRLs were compared with other national and international published values. The DRLs in terms of CTDIvol for abdomen-pelvis, chest, brain and sinus examinations were 3, 8, 9 and 10 mGy; 4, 5, 5 and 5 mGy; 25, 28, 29 and 38 mGy; and 23, 24, 26 and 27 mGy for four different age groups of ≤1-, 1-5-, 5-10- and 10-15-y-old, respectively. The DRL values in terms of DLP were 75, 302, 321 and 342 mGy.cm; 109, 112, 135 and 170 mGy.cm, 352, 355, 360 and 481 mGy.cm; and 206, 211, 228 and 245 mGy.cm, respectively, for the mentioned age groups. In this study, the DRL and AD values in the brain examination were greater among the other studied regions. The DRL plays a critical role in the optimization of radiation doses delivered to patients and in improving their protection. This study provides the local DRLs and ADs for the most common pediatric CT scanning in Yazd province to create optimum situation for the clinical practice.