We conducted a cross-sectional study on radiological safety and the practice of pediatric radiology in general reference hospitals in Kongo Central Province in the DRC.

Our investigation sites consisted of six general reference hospitals in Kongo Central province; namely the General Reference Hospitals of Matadi, Boma, Moanda, Kisantu, Luozi, and Kasangulu. The study was conducted over a period of October to April 2024.

Radiologist and non-radiologist health professionals working in the health facilities concerned by the study constituted our target population.

We surveyed a convenience sample of 50 health professionals including 10 radiologists working in the six general reference hospitals concerned by the survey; namely: Matadi GRH, Boma GH, Moanda GH, Kisantu GH, Luozi GH, and Kasangulu GH. A questionnaire related to the evaluation of radiological safety in pediatric radiology was submitted to them. We used weighted stratified sampling to determine the number of health professionals to survey by category (Radiologist or non-radiologist).

For this study, the techniques used for data collection are face-to-face interviews using a semi-open questionnaire and participant observation.

Except for general aspects relating to the observance of radiation protection principles by all categories of health professionals for the safety of patients and the environment; the following parameters were the subject of our investigations for the eight examinations on the list of the International Commission on Radiological Protection in pediatrics: X-ray penetration (voltage in kilovolts), focus-film distance (FFD in cm); X-ray quantity in milliampere-seconds (MAS) and entrance surface dose. The entrance surface dose for each radiology department was calculated based on the above radiophysical parameters of the pediatric radiology examination protocol using the following formula:

$\text{DE}=0.15\ast {\left(\text{U}/100\right)}^2\ast \text{Q}\ast {\left(100/\text{FFD}\right)}^2$ [9] .

where:

U is the high voltage in KV

Q is the charge in MAS

FFD is the focus-film distance

The Student’s t-test was useful to us as it allowed us to compare means to see if the difference between the mean doses of the surveyed hospitals and those of the International Commission on Radiological Protection is statistically significant or not. The chi-square test also allowed us to analyze the proportions between health personnel who observe radiation protection principles and those who do not.

The results of this study will allow us to consider continuing education or capacity building of health personnel on radiation protection on the one hand, and on the other hand, to readjust the radiation protection course program in initial training to perpetuate radiological safety for maximizing the protection of patients and the environment against the harmful effects of X-rays.

Table 1 informs us that many among the health personnel of the surveyed health structures in Kongo Central were non-radiologists, namely 80%.

Table 2 indicates that a large number of the surveyed health structures in Kongo Central were from the public sector, namely (83.3%).

Looking at Table 3 , the vast majority of radiology personnel said that a large number of radiological examinations prescribed for children are not justified. Still according to this table, in the health structures of Kongo Central, there is a statistically non-significant difference between radiology health personnel who declared the non-justification of radiological examinations prescribed for children compared to those of other categories (p ≤ 0.05).

According to Table 4 , the vast majority of radiology health personnel emphasized that more than 30% of radiological examinations prescribed for children prove to be unjustified. Also, this same table shows that the difference is not statistically significant between the extent of unjustified examinations reported by radiologists and that reported by non-radiologists (p ≥ 0.05).

According to Table 5 , relating to the analysis of the level of contribution to the optimization of radiation protection in pediatric radiology in health structures of Kongo Central, there is a statistically significant difference between radiologists and other health personnel (p ≤ 0.05).

According to Table 6 , there is a statistically significant difference between radiologists and other health personnel who have knowledge of dosimetric evaluation of the department in the practice of pediatric radiology and those who do not have related knowledge (p ≤ 0.05).

According to Table 7 , comparing the DRLs/ESDs of the General Hospital of Massa in Kasangulu with the DRLs/ESDs of the ICRP in pediatrics, there is a statistically non-significant difference in means (t > 0.05). As such, the department is less irradiating for children at GRH/Massa.

According to Table 8 , there is a statistically very significant difference in means between the DRLs/ESDs of the General Hospital of Boma and the DRLs/ESDs of the ICRP in pediatrics (p = 0.05). Therefore, the radiology department of the General Hospital of Boma is highly irradiating in pediatrics.

Table 9 shows that there is a statistically very significant difference in means between the DRLs/ESDs of the General Hospital of Moanda and the DRLs/ESDs of the ICRP in pediatrics. Thus, the department is highly irradiating in pediatrics (p = 0.05).

According to Table 10 , there is a statistically significant difference in means between the DRLs/ESDs/PED. of the General Reference Hospital of Kisantu (GRH/KISANTU) in Kongo Central and the DRLs/ESDs/PED. of the ICRP in pediatrics (p < 0.05). Consequently, the department is irradiating for children at the General Reference Hospital of Kisantu in Kongo Central.

According to Table 11 , there is a statistically significant difference in means between the DRLs/ESDs/PED. of the General Reference Hospital of Luozi in Kongo Central and the DRLs/ESDs/PED. of the ICRP in pediatrics (p < 0.05). The department is highly irradiating for children at GRH/LUOZI.

According to Table 12 , there is a statistically very significant difference in means between the DRLs/ESDs/PED. of the Provincial General Reference Hospital of Matadi and the DRLs/ESDs/PED. of the ICRP in pediatrics (p > 0.05). The department is highly irradiating for children at PGRH/Matadi.

Many of our respondents were non-radiologists, namely 80%. This distribution was made possible thanks to stratified sampling weighted and proportional to the number of each category to avoid underestimating or overestimating one category or another. Also, 83% of the surveyed establishments were state-owned ( Table 1 , Table 2 ).

In Kongo Central, many of the surveyed radiology health personnel reported that more than 30% of radiological examinations requested for children are not justified. To avoid frustrating patients who have already been reassured by requesting doctors or nurses, the services are obliged to receive them for examination, rightly or wrongly. These results corroborate those found by B. Bope Kwete M and others, in their article on evaluation of dosimetry in pediatric radiology in Bukavu, South Kivu in the DRC [10] .

Also, the vast majority of radiology personnel openly stated that many radiological examinations prescribed for children are not justified. Still, according to this table, in the health structures of Kongo Central, there is a statistically non-significant difference between radiology health personnel who declared the non-justification of radiological examinations prescribed for children compared to those of other categories ( Table 3 ). Looking at Table 4 , the vast majority of radiology health personnel emphasized that more than 30% of radiological examinations prescribed for children prove to be unjustified. Also, this same table shows that the difference is not statistically significant between the extent of unjustified examinations reported by radiologists and that reported by non-radiologists (P ≥ 0.05)

The analysis of the degree of contribution to the optimization of radiation protection in pediatric radiology in health establishments in Kongo Central shows a statistically significant difference between radiologists and other health personnel; consequently, the contribution is negative in both categories. Also, a statistically significant difference was found between radiologists and other health personnel who have knowledge of dosimetric evaluation of the department in the practice of pediatric radiology and those who do not have related knowledge (P > 0.05). ( Table 5 , Table 6 ). These results are almost close to those found by B. Bope Kwete M and others in the article “Knowledge and practices of Health professionals on the Optimization of Radiation Protection in Diagnostic Radiology in Children and Adults in the General Referral Hospitals of Bukavu in South Kivu, DRC, JBM, 2022”. But the bitter observation is that these results are very far from the recommendations of the ICRP [10] .

As can be seen, the various radiophysical indices varied according to the service and would also depend on the device but especially on the level of maintenance and regular control of the latter.

The General Hospital of Boma gave entrance surface doses in children that are significantly above the norm of the International Commission on Radiological Protection for the following examinations: pelvis 3mGy and lateral skull 2.7mGy. Also according to this same table, there is a statistically very significant difference in means between the DRLs/ESDs of the General Hospital of Boma and the DRLs/ESDs of the ICRP in pediatrics (p < 0.05). Thus, the radiology department of the General Hospital of Boma is highly irradiating in pediatrics ( Table 8 ). Also, Table 9 shows that there is a statistically very significant difference in means between the DRLs/ESDs of the General Hospital of Moanda and the DRLs/ESDs of the ICRP in pediatrics. Thus, the department is highly irradiating in pediatrics (p > 0.05).

According to Table 10 , there is a statistically significant difference in means between the DRLs/ESDs/PED. of the General Reference Hospital of Kisantu (GRH/KISANTU) in Kongo Central and the DRLs/ESDs/PED. of the ICRP in pediatrics (p < 0.05). Consequently, the department is irradiating for children at the General Reference Hospital of Kisantu in Kongo Central. According to Table 11 , there is a statistically significant difference in means between the DRLs/ESDs/PED. of the General Reference Hospital of Luozi in Kongo Central and the DRLs/ ESDs/PED. of the ICRP in pediatrics (p < 0.05). The department is irradiating for children at GRH/LUOZI. According to Table 12 , there is a statistically very significant difference in means between the DRLs/ESDs/PED. of the Provincial General Reference Hospital of Matadi and the DRLs/ESDs/PED. of the ICRP in pediatrics (p < 0.05). The department is highly irradiating for children at PGRH/Matadi. The results of Table 10 , Table 11 , and Table 12 deviate significantly from the recommendations on good practices in radiation protection included in the PRP-HOM and IRSN report (2014) [11] .

It is thanks to the various radiophysical indices (voltage in KV, charge in mAs, and focus-skin distance in cm) that we were able to calculate the entrance surface dose, which is equivalent to DRL, using the following formula: 0.15*(U/100)*Q* (100/DFP) in children (ICRP, 2011) [9] [12] .

For our study, the brand of the devices matters little because our main concern remains the dose rate or entrance dose for each examination in adults as well as in pediatrics. DRLs are dosimetric indicators of the quality of practices allowing to identify situations requiring corrective action in pediatric radiology for the protection of children and the environment [12] [13] . The observation is generally deplorable because radiological safety is far from being ensured as five radiology departments out of the six surveyed are irradiating in children. The reasons for the observed deviation from the ICRP recommendations include equipment malfunctions due to the lack of regular quality control of radiological installations and insufficient training of professionals in radiation protection. One can realize the level of exposure of children and the environment. Due to their increased sensitivity to radiation and their longer remaining lifespan, children deserve special attention in the practice of pediatric radiology, although radiation protection should benefit patients of all ages, health professionals, and the environment given the high risks associated with ionizing radiation [14] [15] .