This research measured the entrance surface radiationdose to the gonadal region of male patients’ who were underwent the lumbarspine X-ray examinations and analyzed the testicular radiation doses with thepatients’ BMI.Male patients’ testicular region received highradiation dose in lumbar spine X-ray examination after hip, pelvis andabdominal X-ray examinations (Wall, et al., 2011). ESD is also high for alumbar spine examination (Aliasgharzadeh, et al., 2015).
ESD vary with exposureparameters while exposure parameters vary with the patient body thickness, typeof the equipment, imaging method, FFD, image processing conditions and alsodifferent radiographic persons. With applying of same conditions for a specificprojection, one radiographer will use minimum possible exposure factors whileanother person using the maximum possible exposure parameters for the sameexamination. According to the above circumstances researchers wereused same X-ray equipment (Shimadzu), imaging method (CR), 100cm FFD and16*43cm FOV with same exposure factors specified for the lumbar spine region ondigital radiographic unit (300mA,80kV,71mAs for AP and 300mA,80kV,80mAs forlateral). According to test results total mean testicularradiation dose varies from 41.066µSv to 131.
990µSv while the mean value was73.356µSv. Previous researchers said that the doses as low as 0.15Gy willreduce the sperm count and doses greater than 0.5Gy and 6Gy will result absenceof living spermatozoa and permanent sterility, respectively (Amanda, et al., 1993).With conversion of these values in to equivalent dose values, shows that thereis no possible effect on testes with our test results for temporary orpermanent sterility. BMI was selected as a variable to compare the patient testicularradiation dose in two lumbar spine projections.
In this research 16.10 to 36.20BMI range was observed within the population with 23.47 mean value. Variationbetween above parameter and total testicular radiation dose, AP and lateral testicularradiation doses were analyzed separately.
According to the analyzed result lesspositive correlation was found between patient BMI and AP testicular radiation dose. Previous study conducted in Sri Lanka evaluatedthe testicular radiation dose during the KUB radiography also found the similarresult that there is a weak positive correlation between BMI and testicularradiation dose (Horadigala and Jayasinghe, 2014). In the present study, pearsoncorrelation test identified that the less negative significant correlationbetween testicular radiation dose in lateral projection and patient BMI whiletotal testicular radiation dose shows least negative correlation with patientBMI. Distribution of AP and lateral dose values, totaltesticular dose and BMI values were tested by normality test and determinedthat distribution of total testicular ESD, ESD in lateral and patient BMI werenot normally distributed (p<0.
05). Testicular radiation dose in APprojection was normally distributed with normality test. The result of this study shown that the meantesticular radiation dose in lumbar spine AP projection was 58.79µSv with34.05µSv to 79.99µSv dose range while mean testicular radiation dose in lumbarspine lateral projection was 14.55µSv with 1.37µSv to 52.
00µSv dose range. Froma simple calculation above two mean values, around 75% of testicular radiationdose reduction was achieved in lumbar spine lateral projection with respect to theAP projection. As a percentage, testicular dose reduction (72%) in lumbar spinelateral than the AP projection nearly equal to previous research done inIreland with 0.036mGy testicular AP dose and 0.
0102mGy testicular lateral dose(conor, et al., 2009). The previous study prove that lumbar spine lateralprojection already receives the testicular dose reduction due the laterallocation of the iliac bone (conor, et al.
, 2009). Present study result(14.55µSv) also compatible with their results. According to the literature, research study done inIndia found that mean SRD to the testes from lumbar spine AP as 282.29µGy in CRand 75.24µGy in DDR with 70% dose reduction in DR than CR while testes dosefrom lumbar spine lateral was 506.69µGy in CR and 96.
02µGy in DR with 78% dosereduction with DR than CR (Priyankara, et al). Present study test values wasnot compatible with these values and it may be due to manual selection ofexposure factors by radiographer in CR system and Philip medical systemsautomatic exposure control (AEC) based factors select for the DR system. Theywere proved that with the use of AEC in DR system could reduce the patienttesticular SRD. Present study also used the AEC for select the exposureparameters and test results revealed that lower doses received by the testeswith Sri Lankan practice. Another related research study on reduction ofradiation risks in patients underwent some X-ray examinations by using optimalprojections with monte-carlo mathematical calculation found that the 0.429mGymean absorbed dose with AP and 0.
053mGy mean testicular absorbed dose withlumbar lateral projection received for standard sized patient with 178.6cmheight and 73.2Kg weight (Chaparian, et al.
, 2013). Present study results weredeviate from these values and it may be due to use of different X-ray unit withdifferent exposure parameters and radiation field size.