Conversion factors for effective dose and organ doses with the air Kerma area product in hysterosalpingography

Histerosalpingography (HSG) remains the dominant diagnostic tool for investigation of infertility in women. Conversion factors used to estimate effective (E) and organ doses (H_T) from air Kerma area product (KAP) are needed to estimate patient doses in HSG, performed with state-of-the-art fluoroscopic X-ray systems with digital detectors. In this study, estimates of E and H_T for six critical organs/tissues, were derived on an individual basis in 120 HSG procedures and in 1410 irradiation events, performed on two X-ray systems from information available through the radiation dose structured report using Monte Carlo methods. Mean values of E and H_ovaries were1.0 ± 0.9 mSv and 5.6 ± 5.4 mGy. E/KAP conversion factors of 0.13; 0.18; 0.28 and 0.35 mSv Gy^-1cm^-2 were established for irradiation events with a Cu filtration of 0.0; 0.1; 0.4 and 0.9 mm. A high agreement was obtained between E estimated through Monte Carlo methods and E/KAP conversion factors accounting separately for the different modes of fluoroscopy and the radiography component of HSG, with a systematic error of 0 mSv and lower/upper limits of agreement of -0.6 and 0.5 mSv. On the contrary, the use of a single coefficient of conversion did not provide accurate estimates of E, showing a bias of -0.4 mSv and lower and upper limits of agreement of -1.9 and 1.2 mSv. An algorithm for the estimation of effective and organ doses from KAP has been established in HSG procedures depending on the Cu filtration in the X-ray irradiation events.