Tube housing leakiness radiation and patient related radiation protective measures - Gonads radiation exposure from panoramic radiography

Abstract

The purpose of this study was to compare patient- and apparatus related radiation protective measures considering gonad radiation exposure at panoramic radiography. The local dose (yGv) in the region of the gonads of a male Alderson-Rando-Phantom was measured by the dosimeter Tol-F (Berthold Technology, Germany) during panoramic radiography (PR) by the digital Orthophos XG plus®(Sirona / Bensheim, Germany). Different radiation protective measures was investigated during constant exposure parameters. In the second part of the survey the same ionisation chamber recorded the scattered radiation at the gonads level of the none protected phantom at various case shielding. Without protection apron the dose near to gonads amounted to 0,36 μGy in the mean (initial value), with ventrally applied X-ray apron 0,05 μGy (86% dosage reduction) and with ventral semi apron 0,025 μGy (93 % dosage reduction). At the investigation of tube housing leakiness radiation on the gonads level of the phantom 0,38 μGy was measured, at closed collimator (5mm lead) 0,36 μGy, at shielding the bottom of the apparatus 0,01 μGy. During a PR with opened Collimator (normal collimation) and additional basal shielding an equivalent dose of 0,03 μGy could be ascertained. The reinforced shielding at the bottom of the apparatus reduced the gonads radiation exposure to 92%. Concerning the gonadal protection the optimized patient related and the reinforced apparatus related radiation protection did not differ significantly. At Orthophos XG plus® the tube housing leakiness radiation is an significant factor of the nevertheless relative small radiation exposure of the gonads. The obvious reduction of the gonads exposure by ventral applying of apron or semi apron justifies this simple radiation protective precaution. An additional basal shielding on the apparatus fits the same way. At panoramic radiography the scattered radiation from the primary radiation beam is not significant determining the gonad dose. © 2009 Springer-Verlag.