The skin dose of pelvic radiographs since 1896

Abstract

Objectives To derive conversions of antiquated exposure data into modern equivalents and to apply these in the assessment of the skin dose of pelvic radiographs since 1896. Methods The literature 1896–2018 was searched for implicit and explicit dose information. The early implicit dose data contained now obsolete descriptions of radiation quality and quantity for long since disappeared X-ray systems of limited efficiency. Converting the old information into modern specifications was achieved using contemporary data and computer simulations. Final dose calculations were done with modern software. Explicit radiation doses of later date reported in old quantities and units were adapted according to current recommendations. Results For the period before 1927 conversion algorithms for spark gap data and penetrometer hardnesses to high voltage could be derived. Electrical and X-ray efficiencies of several old röntgen systems were determined. Together they allowed reconstruction of 53 doses. After 1927 doses were generally explicitly specified; 114 were retrieved. Although an enormous spread was observed, the average skin dose was reduced by a factor of about 400. Conclusions Antiquated exposure data were successfully used for dose reconstruction. Extreme dose variability was a constant. Efforts to cut down doses were effective as skin doses went down from sub-erythema values to about one milligray. Electronic supplementary material The online version of this article (10.1186/s13244-019-0710-1) contains supplementary material, which is available to authorized users.

Gonad shielding in pelvic radiography: modern optimised X-ray systems might allow its discontinuation

“…Radiation dose of an AP pelvic radiograph over time Figure 3 shows all dose data, reconstructed and retrieved, as "entrance surface air kerma including backscatter" (ESAK) [61]. An enormous spread in dose can be observed at all times and an average dose decrease between 1896 and 2018 by a factor of about 400.…”

“…Please note the logarithmic y-axis. The solid line is a fit of a simple exponential function to all data ("exponential regression") [61] no negative side-effects as done for Table 5, gonad shielding causes a very small reduction in risk only.…”

“…Third, more recent insights into radiation biology have led to lower estimates of hereditary risks. According to current understanding, radiation-induced mutations generally do not come to expression in descendants, because, in the words of ICRP 103: "Most radiationinduced mutations are large multigene deletions, which are more likely to cause multisystem developmental abnormalities rather than single-gene (i.e., Mendelian) ESAK entrance surface air kerma which includes backscatter (dose in air but on the skin) [61], KAP product of kerma free in air and area of primary X-ray beam, DRL diagnostic reference level a With optimal shielding, these doses might be reduced by about 95% and 50%, respectively b…”

“…Pulsed voltages were used. The equivalent DC voltage was calculated on the basis of effective dose in the same way as kV peak was converted to DC-kV on the basis of kerma free in air [61] a Cumulative effective dose is the sum of the effective dose over all exposed persons in the 35 countries (k in kman-Sv stands for kilo, i.e. 1000) b Assuming AP projection dominates pelvic effective dose given in RP180 c Most common DRL in Europe is a KAP of 3.0 Gy cm 2 , also in the Netherlands [70].…”

“…All dose data, reconstructed and retrieved, were presented as "entrance surface air kerma including backscatter" (ESAK). Because of its large size, this study was published separately [61]. Using the ESAK values obtained, it is possible to estimate effective dose and gonad doses by first converting the ESAK values to kerma free in air (KfiA) (by dividing ESAK by the backscatter factor) and then using the KfiA as input in PCXMC [62,63].…”