This is a cross-sectional study about the evaluation of the knowledge and practices of health professionals on the optimisation of radiation protection in paediatrics and adults in the general hospitals of BUKAVU in South Kivu, DRC.

The three BUKAVU general referral hospitals were the site of our investigations. These were the BUKAVU General Referral Hospital (HPGRB), MWANZI clinic, CIRIRI General Referral Hospital and PANZI General Referral Hospital.

Our target population was radiologists and non-radiologists working in the health structures concerned by the study.

We surveyed a convenience sample of 73 health professionals, including 23 radiologists working in the four general referral hospitals concerned by the survey: BUKAVU General Referral Hospital, MWANZI Clinic, PANZI General Hospital and CIRIRI General Hospital. A questionnaire related to knowledge and practices on the optimisation of radiation protection in paediatrics and adults was submitted to them.

- To be a health professional radiologist or non-radiologist;

- To be an actual staff of the hospitals to be surveyed and to agree to answer our questions.

Apart from aspects related to the knowledge and practices of health care staff on optimising radiation protection, the following parameters were investigated for the eight examinations on the International Commission on Radiological Protection’s list for paediatrics and adults: X-ray penetration (voltage in kilovolts), focal spot distance (FDF in cm); X-ray quantity in milliampere-seconds (MAS); and entrance dose. The entrance dose for each radiology department was calculated on the basis of the above radiophysical parameters of the paediatric and adult radiology examination protocol using the following formula:

DE = 0.15 ∗ ( U / 100 ) 2 ∗ Q ∗ ( 100 / DFF ) 2

where:

U is the high voltage in KV;

Q is the load in MAS;

DFF is the distance between the focus and the film.

The entry doses obtained in each radiology unit of the hospitals concerned were compared to the ICRP diagnostic reference level (DRL) using the Student’s T test, as the parameters were comparable to the matched data. The chi-square test also allowed us to analyse the proportions of health care workers in relation to knowledge and practices on the optimisation of radiation protection.

The expected results will allow us to consider training or capacity building of health care workers on radiation protection on the one hand and on the other hand to conform the radio-physical parameters to the ICRP requirements in order to promote the optimisation of radiation protection for the safety of patients, the public and health care professionals.

Table 1 shows that many of our respondents were non-radiologists (68.5%). Table 2 shows that 75.5% of the health structures surveyed were public.

In view of Table 3, there was no association between professional category and the level of knowledge of radiologists versus non-radiologists on the effects of radiation (P > 0.005).

Looking at Table 4, an association was found between the professional category and the level of knowledge about radiation protection standards (P < 0.05).

According to Table 5, there is a statistically insignificant difference between healthcare professionals with knowledge of the principle of radiation protection related to their category and those without such knowledge (P > 0.05).

Looking at Table 6, there was no association between professional category and knowledge of International Commission on Radiological Protection’s diagnostic reference levels (P > 0.05).

According to Table 7, there is a statistically insignificant difference between radiologists and non-radiologists in terms of knowledge of the main source of artificial radiation (P > 0.05).

ICRP: International Commission on Radiological Protection; DRL: Diagnostic Reference Level.

According to Table 8, there was no association between the level of contribution to the optimisation of radiation protection of healthcare workers and the professional category (P > 0.05).

Many of our respondents were non-radiologists, i.e. 68.5%; this distribution was made possible by the weighted stratified sampling proportional to the number of staff in each category. Also 75% of the structures surveyed were state-owned (Table 1, Table 2).

Tables 3-6 show that there is a statistically insignificant difference between the proportion of radiologists who know about the effects of radiation compared to the other categories.

Radiologists with sufficient knowledge of radiation protection standards have a high proportion compared to other health professionals.

The majority of radiologists and non-radiologists alike are unaware of the diagnostic reference levels or entry doses for some common examinations given by the International Commission on Radiological Protection.

According to Table 6, only 34.5% of the radiologists surveyed know the diagnostic reference levels, while 64% do not. On the non-radiologist side, 36% were aware of the International Commission on Radiological Protection’s entry dose levels compared to 64% who were unaware of them.

Although these entry doses are calculated on the basis of data resulting from the radiophysical parameters used in the different radiology departments, it is of great importance that practitioners are aware of the ICRP diagnostic reference levels as an indicator for assessing the degree of irradiation in their department [3].

The truth is that the technical constraints related to the lack of maintenance and lack of controlling equipment quality by radiophysics specialists push most radiologists to produce even irradiating doses with the probability of repeating examinations, even though the radiation protection standards advise against it.

The data in the three tables above are similar to those obtained by Health Canada in its 2015 report on radiation exposure in Canada [9].

Table 8 shows that there is a statistically insignificant difference between the proportion of radiologists who contribute positively to optimizing radiation protection in the diagnostic use of X-rays and those who do not.

Thus, only 56% of radiologists provide technical conditions that allow for dose limitation in their work. In view of this finding, radiation remains a real problem in BUKAVU hospitals. The results of Table 10 are significantly different from those found by Abbat, Lakey and Mathias in their study conducted in France on protection against radiation [11]. The survey carried out by the latter showed that radiologists as well as prescribers or applicants for examinations contribute in their great majority to the limitation of doses in the diagnostic use of X-rays.

Tables 9-16 give the different radio physical indices (voltage in KV, charge in MAS and focal spot to skin distance in Cm) which allowed us to calculate the doses at the entrance of the body for some common examinations in adults and children using the formula: 0.15 × (U/100) × Q × (100/DFP) [12].

As can be seen, these different radio physical indices vary according to the service, the level of maintenance and regular control of the service. For our study the brand does not matter as our main concern is the dose rate or input dose for each examination in both adults and paediatrics.

According to Table 17 and Table 18, there is a statistically insignificant difference between the entry doses produced by the radiology department of the BUKAVU Provincial General Reference Hospital and those of the ICRP for adults. As can be seen, the EDs of the HPGRB are slightly higher than or equal to those of the ICRP for adults for some common examinations.

This being the case, the HPGRB radiology department does not irradiate adults, all other things being equal. These data are similar to those found by Duriez in his study on the production of X-rays and their application in medical and industrial radiography.

On the other hand, for the data in Table 18, there is a statistically significant difference between the input doses produced by the HPGRB and those of the ICRP in paediatrics for some common examinations. In this respect, the radiology department of the HPGRB was found to be very irradiating for children. This finding is bitter because, as we have pointed out, children are among the people for whom particular attention must be paid to their protection against radiation, especially as in children the sensitive organs are closer to the part to be radiographed.

According to Table 19 and Table 20, a statistically insignificant difference was recorded between the entry doses of the radiology department of the MWANZI clinic for some examinations in adults. Thus the department is less radiating for adults but very radiating for children as the difference is statistically significant between the data used by the MWANZI clinic in paediatrics and that of the ICRP. The data or input doses produced by the MWANZI clinic radiology department are very high compared to the ICRP paediatric input data for the same examinations [13].

This is an unfortunate finding because in children, tissues develop rapidly and sensitive organs are closer to the part to be radiographed and also these organs must be subject to better and more effective radiation protection even in the case of a less irradiating radiology department.

Table 21 and Table 22 show a statistically insignificant difference between the input data or doses produced by the radiology department of PANZI Hospital and those of the ICRP in adults for some examinations. In terms of this result, the PANZI radiology department is less radiating for both children and adults. These results are similar to those obtained by Davenport MS, Cohan RH. Caoili EM in their study of X-ray devices for diagnostic use and baggage inspection-precautions in Canada [14].

The good results given by PANZI Hospital would be due to the regular monitoring that the radiology department receives.

According to Table 23 and Table 24, there is a statistically insignificant difference between the CIRIRI hospital’s entry doses and those of the ICRP for adults for the same examinations. On the other hand, a statistically significant difference was observed between the CIRIRI hospital entry doses for children and the ICRP entry doses. The CIRIRI radiology department is radiating to children.

The observation is generally deplorable because out of four radiology services in the major health structures in BUKAVU, three (75%) offer radiology services that are irradiating to children. However, according to the statistics, out of 100% of radiology examinations prescribed, 40% are for children and one can imagine the degree of irradiation for these children, for the public and for the environment. Also, as the service is irradiating, there is unfortunately the possibility of doing an examination more than once for the same cause with the risk of doubling the dose because X-rays have cumulative effects.

At a time when the world is advocating the reduction of the intense production of greenhouse gases, which is a measure of radioprotection against natural irradiation, it is imperative that the optimisation of radioprotection against the abundant and main source of artificial irradiation be put in place because the effects caused by the two sources of irradiation are almost similar.