Radiation Dose Survey of Pediatric Chest Computed Tomography Examinations: A Local Diagnostic Reference Levels Approach to Patient Safety

Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .

Analysis of Local Diagnostic Reference Levels for Pediatric Patients Undergoing 18F-FDG PET/CT Imaging for Oncology

Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDIvol values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .

Radiation Dose from CT-Scan of Childhood’s Head: Results of the First Ivorian Survey in a Single Study Site

Objectives: This study aims to evaluate the level of X-ray doses used in childhood’s head as Local Diagnostic Reference Levels (LDRLs) in computed tomography (CT) at a university hospital in Côte d’Ivoire. The Diagnostic Reference Level (DRL) have been set up and used to prevent unusually high radiation doses used in radiology departments and is therefore an optimization tool for practices and procedures in medical X-ray imaging for the radiation protection of patients. Methods: A prospective study of volume CT dose index (CTDIvol) and dose length product (DLP) was performed on images of childhood’s head obtained from a CT-scanner of 64 bars equipped with the tube current modulation capability and manufactured by Hitachi Medical System. 122 CT-scan data from 55 childhood’s head were analyzed. The scan data were stratified in four age groups: Results: The 75th percentile of CTDIvol and DLP (set as LDRL) obtained with respect to the stratified age groups are: 22.5 mGy and 452.5 mGy∙cm, 27.7 mGy and 690.6 mGy∙cm, 28 mGy and 722.4 mGy∙cm, 33.6 mGy and 736.8 mGy∙cm respectively. These outcome values increase with respect to the age of pediatric patients and are comparable to DRLs values obtained internationally. Conclusions: Obtaining good image quality while using low dose in children’s head computed tomography for radiation protection require to setup more surveys in Côte d’Ivoire for regional and national DRL. We proposed through this survey LDRLs in terms of CTDIvol and DLP, comparable to international DRLs values. This survey will be strengthened by additional surveys in order to obtain national DRLs for the radiation protection of the child patient in Côte d’Ivoire.

Establishment of Dose Reference Levels for Nuclear Medicine in Sudan

In this study, a national survey for establishment of Nuclear Medicine (NM) Dose Reference Levels (DRLs) for adult patients was carried out. The Administrated Activity (AAs) (MBq) was collected from six nuclear medicine departments. Factors influencing the image quality were also observed. The established Sudan National DRLs represent the AA value corresponding to 75th percentile of the AA frequency distribution. Generally, Sudan National DRLs and average AAs are comparable with the papers published in the international literature. All Sudanese DRLs values were found within the international range. While it is noted that the Sudanese DRLs is higher than the values of ARSA except for the MIBI pharmaceuticals that used in both parathyroid and myocardial perfusion scan and for 99mTcDTPA that used for Dynamic Renal scan study the DRLs values were decreased. In compared with UNSCEAR 2008 data, the average dose (MBq) for Sudanese we note that the bone scan falls within the average values while it’s lower in all other scans except for parathyroid scan in which the AAAs increase more than twice. When compared to BSS 1996, it showed variation in increased and decreased AAAs. There may be potential for reducing the higher values of AAs, in co-operation with Nuclear Medicine staff.

A multi-provincial survey and analysis of radiation doses from pediatric CT in China

Objective:To survey and analyze the radiation doses of pediatric CT in some provinces(autonomous region)or municipalities in China,and compare them with the data released by the relevant domestic and international organizations,so as to identify the current status of Chinese pediatric CT radiation doses.Methods:Radiation doses of pediatric CT were collected during August and December 2016 from 40 hospitals(including 18 children’s hospitals)in 15 provinces,municipalities or autonomous regions across the China.The procedures of head CT,chest CT and abdomen CT were selected in these hospitals,and 10 patients in each group of 0-<1 y,1-<5 y,5-<10 y and 10-<15 y were collected at random for every procedure.Weighted CT dose index(CTDI_(w)),volumetric CT dose index(CTDI_(vol))and dose length product(DLP)were used as survey quantities.An independent sample Kruskal-Wallis rank sum test was performed for CTDI and DLP for each procedure for different age groups,and pairwise comparisons were performed for intra-group data.The same statistical method was also conducted for CTDI and DLP of the same procedure and age group in different provinces or municipalities.Results:The 75th percentiles of the distribution of CTDI and DLP in different age groups of 0-<1 y,1-<5 y,5-<10 y and 10-<15 y were as follows:36.5,43.4,49.1,51.1 mGy and 488,635,723,852 mGy.cm for head,6.1,6.4,6.8,9.6 mGy and 108,136,187,293 mGy.cm for chest,10.5,10.3,11.4,13.0 mGy and 251,284,353,523 mGy.cm for abdomen.The 50th percentiles of the distribution of the radiation doses for the same procedure varied with the ages(head,CTDI_(w):H=155.66,DLP:H=212.35,P<0.05;chest,CTDI_(vol):H=85.43,DLP:H=197.36,P<0.05;abdomen:H=62.29,DLP:H=173.22,P<0.05)and with lower dose at lower age.Radiation doses were close for head between 5-<10 y and 10-<15 y groups,for chest between 1-<5 y and 5-<10 y groups and between 5-<10 y and 10-<15 y groups,and for abdomen between 0-<1 y and 1-<5 y groups,with no statistically significant difference(the adjusted P>0.05).The dose levels of different provinces or municipalities in the same procedure and age group were not consistent,and the differences were statistically significant(P<0.05).The data were different from the domestic and international values of DRL.The 75th percentiles of CTDI_(w) and DLP values of head CT were close to the data from Japan and UK(United Kingdom),higher than the data from Korea and EC(European Commission).The 75th percentiles of CTDI values of all age groups were lower than the values of Japan and UK,and larger than that of Korea and EC in chest CT and abdomen CT.Conclusions:The 75th percentile values of the distribution of the pediatric CT doses obtained from the survey were inconsistent with those released by the relevant national and international organizations.It is necessary to update the national DRLs for pediatric CT on the basis of the actual survey data.