Mailed thermoluminescent dosimeter determination of entrance skin exposure and half-value layer in mammography

A method of providing in vivo measurement of entrance skin exposure for mammography using mailed thermoluminescent dosimeters has been developed. The dosimeters are calibrated to 137Cs (662 keV), and a correction is applied to account for energy response. A mailed dosimeter packet which can be used to measure the half-value layer at mammography energies is also described. The results for both systems agree well (to within 10%) with careful ion chamber determinations. These dosimeter measurements provide a simple. Inexpensive means to reliably determine exposure and to monitor machine parameters on a periodic basis.